Negative rebound and disinvestment effects in response to an improvement in energy efficiency in the UK economy

This paper uses a computable general equilibrium (CGE) framework to investigate the conditions under which rebound effects may occur in response to increases in energy efficiency in the UK national economy. Previous work for the UK has suggested that rebound effects will occur even where key elasticities of substitution in production are set close to zero. The research reported in this paper involves carrying out a systematic sensitivity analysis, where relative price sensitivity is gradually introduced into the system, focusing specifically on elasticities of substitution in production and trade parameters, in order to determine conditions under which rebound effects become a likely outcome. The main result is that, while there is positive pressure for rebound effects even where (direct and indirect) demands for energy are very price inelastic, this may be partially or wholly offset by negative income, competitiveness and disinvestment effects, which also occur in response to falling energy prices. The occurrence of disinvestment effects is of particular interest. These occur where falling energy prices reduce profitability in domestic energy supply sectors, leading to a contraction in capital stock in these sectors, which may in turn lead to rebound effects that are smaller in the long run than in the short run, a result that runs contrary to the predictions of previous theoretical work in this area.

NEW METHODS FOR DETECTION, SUSCEPTIBILITY TESTING AND BIOFILM ERADICATION OF DIFFICULT ORGANISMS

Aujourd'hui, les problèmes des maladies infectieuses concernent l'émergence d'infections difficiles à traiter, telles que les infections associées aux implants et les infections fongiques invasives chez les patients immunodéprimés. L'objectif de cette thèse était de développer des stratégies pour l'éradication des biofilms bactériens (partie 1), ainsi que d'étudier des méthodes innovantes pour la détection microbienne, pour l'établissement de nouveaux tests de sensibilité (partie 2). Le traitement des infections associées aux implants est difficile car les biofilms bactériens peuvent résister à des niveaux élevés d'antibiotiques. A ce jour, il n'y a pas de traitement optimal défini contre des infections causées par des bactéries de prévalence moindre telles que Enterococcus faecalis ou Propionibacterium acnés. Dans un premier temps, nous avons démontré une excellente activité in vitro de la gentamicine sur une souche de E. faecalis en phase stationnaire de croissance Nous avons ensuite confirmé l'activité de la gentamicine sur un biofilm précoce en modèle expérimental animal à corps étranger avec un taux de guérison de 50%. De plus, les courbes de bactéricidie ainsi que les résultats de calorimétrie ont prouvé que l'ajout de gentamicine améliorait l'activité in vitro de la daptomycine, ainsi que celle de la vancomycine. In vivo, le schéma thérapeutique le plus efficace était l'association daptomycine/gentamicine avec un taux de guérison de 55%. En établissant une nouvelle méthode pour l'évaluation de l'activité des antimicrobiens vis-à-vis de micro-organismes en biofilm, nous avons démontré que le meilleur antibiotique actif sur les biofilms à P. acnés était la rifampicine, suivi par la penicilline G, la daptomycine et la ceftriaxone. Les études conduites en modèle expérimental animal ont confirmé l'activité de la rifampicine seule avec un taux de guérison 36%. Le meilleur schéma thérapeutique était au final l'association rifampicine/daptomycine avec un taux de guérison 63%. Les associations de rifampicine avec la vancomycine ou la levofloxacine présentaient des taux de guérisons respectivement de 46% et 25%. Nous avons ensuite étudié l'émergence in vitro de la résistance à la rifampicine chez P. acnés. Nous avons observé un taux de mutations de 10"9. La caractérisation moléculaire de la résistance chez les mutant-résistants a mis en évidence l'implication de 5 mutations ponctuelles dans les domaines I et II du gène rpoB. Ce type de mutations a déjà été décrit au préalable chez d'autres espèces bactériennes, corroborant ainsi la validité de nos résultats. La deuxième partie de cette thèse décrit une nouvelle méthode d'évaluation de l'efficacité des antifongiques basée sur des mesures de microcalorimétrie isotherme. En utilisant un microcalorimètre, la chaleur produite par la croissance microbienne peut être-mesurée en temps réel, très précisément. Nous avons évalué l'activité de l'amphotéricine B, des triazolés et des échinocandines sur différentes souches de Aspergillus spp. par microcalorimétrie. La présence d'amphotéricine Β ou de triazole retardait la production de chaleur de manière concentration-dépendante. En revanche, pour les échinochandines, seule une diminution le pic de « flux de chaleur » a été observé. La concordance entre la concentration minimale inhibitrice de chaleur (CMIC) et la CMI ou CEM (définie par CLSI M38A), avec une marge de 2 dilutions, était de 90% pour l'amphotéricine B, 100% pour le voriconazole, 90% pour le pozoconazole et 70% pour la caspofongine. La méthode a été utilisée pour définir la sensibilité aux antifongiques pour d'autres types de champignons filamenteux. Par détermination microcalorimétrique, l'amphotéricine B s'est avéré être l'agent le plus actif contre les Mucorales et les Fusarium spp.. et le voriconazole le plus actif contre les Scedosporium spp. Finalement, nous avons évalué l'activité d'associations d'antifongiques vis-à-vis de Aspergillus spp. Une meilleure activité antifongique était retrouvée avec l'amphotéricine B ou le voriconazole lorsque ces derniers étaient associés aux échinocandines vis-à-vis de A. fumigatus. L'association échinocandine/amphotéricine B a démontré une activité antifongique synergique vis-à-vis de A. terreus, contrairement à l'association échinocandine/voriconazole qui ne démontrait aucune amélioration significative de l'activité antifongique. - The diagnosis and treatment of infectious diseases are today increasingly challenged by the emergence of difficult-to-manage situations, such as infections associated with medical devices and invasive fungal infections, especially in immunocompromised patients. The aim of this thesis was to address these challenges by developing new strategies for eradication of biofilms of difficult-to-treat microorganisms (treatment, part 1) and investigating innovative methods for microbial detection and antimicrobial susceptibility testing (diagnosis, part 2). The first part of the thesis investigates antimicrobial treatment strategies for infections caused by two less investigated microorganisms, Enterococcus faecalis and Propionibacterium acnes, which are important pathogens causing implant-associated infections. The treatment of implant-associated infections is difficult in general due to reduced susceptibility of bacteria when present in biofilms. We demonstrated an excellent in vitro activity of gentamicin against E. faecalis in stationary growth- phase and were able to confirm the activity against "young" biofilms (3 hours) in an experimental foreign-body infection model (cure rate 50%). The addition of gentamicin improved the activity of daptomycin and vancomycin in vitro, as determined by time-kill curves and microcalorimetry. In vivo, the most efficient combination regimen was daptomycin plus gentamicin (cure rate 55%). Despite a short duration of infection, the cure rates were low, highlighting that enterococcal biofilms remain difficult to treat despite administration of newer antibiotics, such as daptomycin. By establishing a novel in vitro assay for evaluation of anti-biofilm activity (microcalorimetry), we demonstrated that rifampin was the most active antimicrobial against P. acnes biofilms, followed by penicillin G, daptomycin and ceftriaxone. In animal studies we confirmed the anti-biofilm activity of rifampin (cure rate 36% when administered alone), as well as in combination with daptomycin (cure rate 63%), whereas in combination with vancomycin or levofloxacin it showed lower cure rates (46% and 25%, respectively). We further investigated the emergence of rifampin resistance in P. acnes in vitro. Rifampin resistance progressively emerged during exposure to rifampin, if the bacterial concentration was high (108 cfu/ml) with a mutation rate of 10"9. In resistant isolates, five point mutations of the rpoB gene were found in cluster I and II, as previously described for staphylococci and other bacterial species. The second part of the thesis describes a novel real-time method for evaluation of antifungals against molds, based on measurements of the growth-related heat production by isothermal microcalorimetry. Current methods for evaluation of antifungal agents against molds, have several limitations, especially when combinations of antifungals are investigated. We evaluated the activity of amphotericin B, triazoles (voriconazole, posaconazole) and echinocandins (caspofungin and anidulafungin) against Aspergillus spp. by microcalorimetry. The presence of amphotericin Β or a triazole delayed the heat production in a concentration-dependent manner and the minimal heat inhibition concentration (MHIC) was determined as the lowest concentration inhibiting 50% of the heat produced at 48 h. Due to the different mechanism of action echinocandins, the MHIC for this antifungal class was determined as the lowest concentration lowering the heat-flow peak with 50%. Agreement within two 2-fold dilutions between MHIC and MIC or MEC (determined by CLSI M38A) was 90% for amphotericin B, 100% for voriconazole, 90% for posaconazole and 70% for caspofungin. We further evaluated our assay for antifungal susceptibility testing of non-Aspergillus molds. As determined by microcalorimetry, amphotericin Β was the most active agent against Mucorales and Fusarium spp., whereas voriconazole was the most active agent against Scedosporium spp. Finally, we evaluated the activity of antifungal combinations against Aspergillus spp. Against A. jumigatus, an improved activity of amphotericin Β and voriconazole was observed when combined with an echinocandin. Against A. terreus, an echinocandin showed a synergistic activity with amphotericin B, whereas in combination with voriconazole, no considerable improved activity was observed.

On Measuring the Efficiency of Monetary Policy

Cecchetti et al. (2006) develop a method for allocating macroeconomic performance changes among the structure of the economy, variability of supply shocks and monetary policy. We propose a dual approach of their method by borrowing well-known tools from production theory, namely the Farrell measure and the Malmquist index. Following FÄare et al (1994) we propose a decomposition of the efficiency of monetary policy. It is shown that the global efficiency changes can be rewritten as the product of the changes in macroeconomic performance, minimum quadratic loss, and efficiency frontier.

Rebound Effects from Increased Efficiency in the Use of Energy by UK Households

In this paper, we use CGE modelling techniques to identify the impact on energy use of an improvement in energy efficiency in the household sector. The main findings are that 1) when the price of energy is measured in natural units, the increase in efficiency yields only to a modification of tastes, changing as a result, the composition of household consumption; 2) when households internalize efficiency, the improvement in energy efficiency reduces the price of energy in efficiency units, providing a source of improved competitiveness as the nominal wage and the price level both fall; 3) the short-run rebound can be greater than the long run rebound if the household demand elasticity is the same for both time frames, however, the short run rebound is always lower than in the long-run if the demand for energy is relatively more elastic in the long-run; 4) the introduction of habit formation changes the composition of household consumption, modifying the magnitude of the household rebound only in the short-run. In this period, household and economy wide rebound are lowest for external habit formation and highest when consumers’ preferences are defined using a conventional utility function.

Bargaining one-dimensional policies and the efficiency of super majority rules

We consider negotiations selecting one-dimensional policies. Individuals have single-peaked preferences, and they are impatient. Decisions arise from a bargaining game with random proposers and (super) majority approval, ranging from the simple majority up to unanimity. The existence and uniqueness of stationary subgame perfect equilibrium is established, and its explicit characterization provided. We supply an explicit formula to determine the unique alternative that prevails, as impatience vanishes, for each majority. As an application, we examine the efficiency of majority rules. For symmetric distributions of peaks unanimity is the unanimously preferred majority rule. For asymmetric populations rules maximizing social surplus are characterized.

Technique for the detection of Toxoplasma gondii antigens in mouse urine

A simple and rapid staphylococcal coagglutination test for the detection of Toxoplasma gondii antigens in mice urine is described. A suspension of protein-A containing Staphylococcus aureus coated with rabbit hyperimmune serum was used as reagent. The sensitivity of the antigen assay was found to be at least 118 ng of the antigen protein per ml. No coagglutination was observed when the reagent was challenged against antigenic solutions of other parasites. The suitability of the method for detecting antigens of T. gondii in urine samples was studied by experimental toxoplasma infection in mice. Before the staphylococcal test, the urine samples were double serially diluted in 0.1 M PBS. From the second day on all samples from infected mice were positive at 1/16 dilution. At this dilution, all samples from non infected mice were negative or did not produce coagglutination. This method might be used in the rapid etiological diagnosis also in human cases of acute toxoplasmosis.

The added value from a general equilibrium analyses of increased efficiency in household energy use

The aim of the paper is to identify the added value from using general equilibrium techniques to consider the economy-wide impacts of increased efficiency in household energy use. We take as an illustrative case study the effect of a 5% improvement in household energy efficiency on the UK economy. This impact is measured through simulations that use models that have increasing degrees of endogeneity but are calibrated on a common data set. That is to say, we calculate rebound effects for models that progress from the most basic partial equilibrium approach to a fully specified general equilibrium treatment. The size of the rebound effect on total energy use depends upon: the elasticity of substitution of energy in household consumption; the energy intensity of the different elements of household consumption demand; and the impact of changes in income, economic activity and relative prices. A general equilibrium model is required to capture these final three impacts.

Methods for field detection of resistance to temephos in simuliids. Larval esterase level and topical application of the insecticide to adults

Two practical field methods for indirect detection of simuliid populations resistant to temephos are proposed. The first is based on high esterase activity in resistant larvae and involves adaptations of a filter paper test in which faintly stained spots indicate susceptible populations and strongly stained ones reveal populations resistant to temephos. The second is based on the resistance to the larvicide when adults are topically exposed, and involves the use of diagnostic doses obtained by the comparison between the LD50 for susceptible and resistant populations. The relevance of such methods is discussed in order to help resistance detection in Simulium pertinax Kollar control programmes.

Overtime Working and Contract Efficiency

We present a wage-hours contract designed to minimize costly turnover given investments in specific training combined with firm and worker information asymmetries. It may be optimal for the parties to work ‘long hours’ remunerated at premium rates for guaranteed overtime hours. Based on British plant and machine operatives, we test three predictions. First, trained workers with longer tenure are more likely to work overtime. Second, hourly overtime pay exceeds the value of marginal product while the basic hourly wage is less than the value of marginal product. Third, the basic hourly wage is negatively related to the overtime premium.

Les nanoparticules, une nouvelle arme contre le crime ?

Nanoparticles, a new tool to deter crime? The detection of fingermarks at a crime scene or on evidence related with a criminal affair constitutes one of the main tasks of the investigators. Fingerprints, due to their uniqueness and invariability in time, remain a key element of an identification process (being for suspects or victims). The main difficulty resides in the fact that, most of the time, fingermarks are not visible through naked eye due to their chemical composition and the small amount of material that is left on the scene. There are said to be latent and their detection requires the application of specific techniques (optical or chemical). If numerous efficient techniques currently exist, there is a continuing quest for developing new techniques or reagents with an enhanced sensitivity towards secretions and with an increased efficiency. This article gives an outline about some currently performed researches based on the use of functionalized nanoparticles to detect latent fingermarks.

Automatic front-crawl temporal phase detection using adaptive filtering of inertial signals

This study introduces a novel approach for automatic temporal phase detection and inter-arm coordination estimation in front-crawl swimming using inertial measurement units (IMUs). We examined the validity of our method by comparison against a video-based system. Three waterproofed IMUs (composed of 3D accelerometer, 3D gyroscope) were placed on both forearms and the sacrum of the swimmer. We used two underwater video cameras in side and frontal views as our reference system. Two independent operators performed the video analysis. To test our methodology, seven well-trained swimmers performed three 300 m trials in a 50 m indoor pool. Each trial was in a different coordination mode quantified by the index of coordination. We detected different phases of the arm stroke by employing orientation estimation techniques and a new adaptive change detection algorithm on inertial signals. The difference of 0.2 +/- 3.9% between our estimation and video-based system in assessment of the index of coordination was comparable to experienced operators' difference (1.1 +/- 3.6%). The 95% limits of agreement of the difference between the two systems in estimation of the temporal phases were always less than 7.9% of the cycle duration. The inertial system offers an automatic easy-to-use system with timely feedback for the study of swimming.

Use of an indirect haemagglutination test, for the detection of Clostridium perfringens type A enterotoxin

An indirect haemagglutination (IH) test is described for the detection of Clostridium perfringens type A enterotoxin, produced by strains isolated from human cases of food poisoning and from contaminated food. Though no strict relationship could be observed between titers in the IH test and the time it took mice to die from the intravenous inoculation of mice (IIM), results of the supernatants examined by both methods demonstrated that the IH test was more sensitive than the ILM one. No unspecific reaction was obtanined int he IH wirh a negative control and the inhibitions of the IH and IIM tests by specific antiserum against C. perfringens enterotoxin showed that the IH test is very spcific. The IH assay is recommended for its sensitivity and easy performance by less-equipped laboratories, by these and other data.

Genomic determinants of the efficiency of internal ribosomal entry sites of viral and cellular origin

Summary : Internal ribosome entry sites (IRES) are used by viruses as a strategy to bypass inhibition of cap-dependent translation that commonly results from viral infection. IRES are also used in eukaryotic cells to control mRNA translation under conditions of cellular stress (apoptosis, heat shock) or during the G2 phase of the cell cycle when general protein synthesis is inhibited. Variation in cellular expression levels has been shown to be inherited. Expression is controlled, among others, by transcriptional factors and by the efficiency of cap-mediated translation and ribosome activity. We aimed at identifying genomic determinants of variability in IRES-mediated translation of two representative IRES [Encephalomyocarditis virus (EMCV) and X-linked Inhibitor-of-Apoptosis (XIAP) IRES]. We used bicistronic lentiviral constructions expressing two fluorescent reporter transgenes. Lentiviruses were used to transduce seven different laboratory cell lines and B lymphoblastoid cell lines from the Centre d'Etude du Polymorphisme Humain (CEPH; 15 pedigrees; n=209); representing an in vitro approach to family structure allowing genome scan analyses. The relative expression of the two markers was assessed by FACS. IRES efficiency varies according to cellular background, but also varies, for a same cell type, among individuals. The control of IRES activity presents an inherited component (h2) of 0.47 and 0.36 for EMCV and XIAP IRES, respectively. A genome scan identified a suggestive Quantitative Trait Loci (LOD 2.35) involved in the control of XIAP IRES activity. Résumé : Les sites internes d'entrée des ribosomes (IRES = internal ribosome entry sites) sont utilisés par les virus comme une stratégie afin d'outrepasser l'inhibition de traduction qui résulte communément d'une infection virale. Les IRES sont également utilisés par les cellules eucaryotes pour contrôler la traduction de l'ARN messager dans des conditions de stress cellulaire (apoptose, choc thermique) ou durant la phase G2 du cycle cellulaire, situations durant lesquelles la synthèse générale des protéines est inhibée. La variation des niveaux d'expression cellulaire de transcription est un caractère héréditaire. L'expression des gènes est contrôlée entre autre par les facteurs de transcription et par l'efficacité de la traduction initiée par la coiffe ainsi que par l'activité des ribosomes. Durant cette étude nous avons eu pour but d'identifier les déterminants génomiques responsables de la variabilité de la traduction contrôlée par l'IRES. Ceci a été effectué en étudiant deux IRES représentatifs : l'IRES du virus de l'encéphalomyocardite (EMCV) et l'IRES de l'inhibiteur de l'apoptose XIAP (X-linked Inhibitor-of-Apoptosis). Nous avons utilisés des lentivirus délivrant un transgène bicistronique codant pour deux gènes rapporteurs fluorescents. Ces lentivirus ont été utilisés pour transduire sept différentes lignées cellulaires de laboratoire et des lignées cellulaires lymphoblastoïdes B du Centre d'Etude du Polymorphisme Humain (CEPH; 15 pedigrees; n=209) qui représentent une approche in vitro de la structure familiale et qui permettent des analyses par balayage du génome. L'expression relative des deux marqueurs fluorescents a été analysée par FACS. Nos résultats montrent que l'efficacité des IRES varie en fonction du type de cellules. Il varie aussi, pour le même type de cellules, selon les individus. Le contrôle de l'activité de l'IRES est un caractère héritable (héritabilité h2) de 0.47 et 0.36 pour les IRES de EMCV et XIAP respectivement. Le balayage du génome a permis l'identification d'un locus à effets quantitatifs [QTL Quantitative Trait Loci (LOD 2.35)] impliqué dans le contôle de l'activité de l'IRES de XIAP.