48 research outputs found
Long-term evolution of an estuarine ecosystem (the Gironde estuary case study)
No full textLes estuaires font partie des écosystèmes les plus productifs de la planète. Ils constituent une zone d'importants échanges de matières et jouent à ce titre un rôle capital pour les cycles biogéochimiques. Du fait de leur position à l'interface entre domaines continental et marin, ils sont également un lieu de passage obligatoire pour de nombreuses espèces de poissons migrateurs ou encore de nourricerie et de refuge. Ces systèmes sont contraints par de nombreuses pressions de natures diverses dont certaines en lien avec les activités humaines locales (p. ex. pêcheries, transport maritime, dragages, pollutions accrues, etc.). Ces altérations viennent s'ajouter à la variabilité intrinsèque de ces systèmes naturellement complexes (variabilité spatio-temporelle de différents facteurs environnementaux ; c.-à-d. température, salinité, turbidité, etc.). Toutefois, une intensification de ces d'altérations, dont une partie est associée à la composante climatique des changements globaux, est observée depuis ces dernières décennies. Ces modifications avérées et leurs incidences sur les communautés biologiques constituent un enjeu en matière de gestion des écosystèmes estuariens. Cependant, par manque de chroniques de données continues suffisamment longues, peu d'études sur l’évolution à long terme de systèmes estuariens ont été réalisées à ce jour. Pour mes travaux, j'ai eu à ma disposition un ensemble de chroniques uniques - acquises depuis 35 ans - associées à plusieurs suivis écologiques de l'estuaire de la Gironde (notre site atelier). L'objectif général de cette thèse est de caractériser l’évolution globale du système dans son ensemble (physico-chimie et biologie) et d'identifier les forçages impliqués. L’originalité de ces travaux, par rapport aux études spécifiques déjà menées, consiste à analyser l’évolution de l’ensemble des descripteurs caractéristiques du fonctionnement d'un système modèle et de qualifier la part relative aux forçages globaux. L'étude des séries chronologiques, via une approche end-to-end basée sur des analyses multivariées, permet d'identifier deux changements abrupts d'état de l'écosystème de l'estuaire de la Gironde, associés à des fluctuations hydroclimatiques à large échelle (bassin Atlantique nord) mais aussi à une échelle plus locale (estuaire). Des hypothèses relatives aux possibles mécanismes impliqués, reliant les altérations climatiques à large échelle aux altérations observées à l'échelle des communautés biologiques estuariennes, sont discutées. Un deuxième volet de la thèse, au travers d’une approche modélisatrice basée sur le concept de niche d'Hutchinson, permet d'identifier un changement de répartition spatiale, longitudinale, des populations de copépodes estuariennes en réponse au réchauffement des masses d'eau et à la marinisation de l'estuaire. Enfin un troisième volet de mes travaux s'est consacré à l'étude spécifique d'une espèce de copépode invasive : Acartia tonsa. Suivant une double approche modélisatrice permettant d'estimer à la fois les niches fondamentale et réalisée de l'espèce, ces travaux illustrent l'importance relative des changements climatiques qui ont facilité la colonisation et l'essor de cette espèce dans l'estuaire.Estuaries are among the most productive ecosystems on Earth. They constitute important areas for materials exchanges and play therefore a crucial part in biogeochemical cycles. Because of their location at the interface between marine and continental realms, they are also a migratory path for different fish species and in some cases, a nursery or a refuge area. These systems are submitted to many pressures, some of them being related to anthropogenic activities (e.g fisheries, maritime traffic, dredging, rising pollutions, etc.). These changes are superimposed to the intrinsic variability of these naturally complex ecosystems (characterized by a spatio-temporal variability of different environmental factors; i.e., temperature, salinity, turbidity, etc.). However, since recent years, an intensification of these alterations, being partly linked to the climatic component of Global Change, is observed. These changes, already documented, and their incidence on biological communities, constitute a challenge for the future management of estuarine ecosystems. However, due to a lack of long-term continuous time series, for now few studies on the long-term evolutions of estuarine systems have been reported. In this work, I used a unique set of data (35 years) provided by an ecological monitoring of the Gironde estuary (the model of estuary used in the study). The main objective of this thesis is to characterize the evolution of the whole system (physico-chemistry and biology) over the last three decades and to identify the forcings involved. The originality of this work comes from a global analysis of the main estuarine descriptors and from the evaluation of the relative contribution of global forcings. A study based on multivariate analyses, through an end-to-end approach, reveals two abrupt shifts in the state of the ecosystem of the Gironde estuary. These two changes appear to be linked to hydroclimatic fluctuations at a regional scale (North Atlantic basin) and also at a local scale. Some hypotheses on the possible mechanisms involved, linking the large-scale climatic alterations to the changes observed on the biological estuarine communities are discussed. A second study that uses a modeling approach based on the ecological niche concept of Hutchinson, identifies a change in the spatial (longitudinal) distribution of estuarine copepod populations in response to warming and marinisation processes. Finally, a third work focuses on an invasive copepod species: Acartia tonsa. A double modeling approach estimates both the fundamental and realized niches of the species. The results highlight the relative importance of climate changes that facilitated the colonization of the estuary by A. tonsa
Production primaire et fonctionnement écologique en milieu estuarien turbide : cas de l’estuaire de la Gironde (France)
No full textLa compréhension des processus écologiques affectant la matière transitant ou produite dans les estuaires nécessite une bonne connaissance des facteurs qui contrôlent le développement des différents groupes biologiques et leurs relations trophiques dans le milieu.Les milieux estuariens macrotidaux sont le plus souvent caractérisés par des fortes turbidités qui limitent généralement la production primaire locale. Ils présentent cependant une forte productionsecondaire et des concentrations en chlorophylle non négligeables dans la colonne d’eau. L’une des problématiques demeure donc l’origine de cette production primaire dans les eaux turbides de ces milieux. Cette thèse s’inscrit dans cette logique ; dans la continuité des travaux réalisés précédemment. Elle vise à analyser l’importance et le rôle de la production primaire dans la production globale de l’estuaire de la Gironde. Le présent manuscrit résume ainsi l’ensemble des travaux réalisés et lesrésultats obtenus sur les principaux groupes de producteurs primaires (phytoplancton et microphyto-benthos) présents le long du continuum fluvio-estuarien de la Gironde. Les principales questions qui sont développées dans ce travail structurent ce rapport en trois axes de recherche. Le premier axe permet, au moyen d’une modélisation 1D de transport et réaction, de simuler,dans l’espace et le temps, la dynamique de la chlorophylle-a et des sels nutritifs, témoins d’uneproduction primaire dans le milieu. Les résultats indiquent que la dynamique de la chlorophylle-adans la Gironde reste fortement dépendante des débits et des temps de résidence très courts des massesd’eau, renforçant ainsi une origine allochtone du phytoplancton. Parmi les sources potentielles deproduction d’origine allochtone présents dans la colonne d’eau, les microalgues benthiques jouent unrôle majeur puisqu’elles peuvent être remises en suspension au cours de chaque marée. L’analyse dece compartiment et de sa production a permis dans un second axe de travail, de montrer que les zonesintertidales situées en aval de l’estuaire sont les plus productives et sont majoritairement autotrophes.Elles produiraient relativement plus de matière que les zones situées en amont qui elle, sont fortementinfluencées par les débits des fleuves.Finalement dans le troisième axe, les différentes voies de transfert de la matière organique au seindu réseau trophique, où les copépodes occupent une place prépondérante, sont analysées au moyendu traçage par les isotopes stables de carbone et de l’azote (13C et 15N)Abstrac
Dynamique de transfert des matières organiques et inorganiques le long du continuum fluvial de la Garonne (impact de la retenue de Malause)
No full textRivers are mainly responsible for organic and inorganic matter transfers from continents to oceans. These matters can be separated by filtration (generally at 0,45 or 0,22 m) into particulate and dissolved phases. The behaviour of organic fractions depends on their origin. The labile fractions are often rapidly mineralized during their transfer, whereas the refractory fractions have a conservative behaviour. We studied the dynamic of all organic and inorganic fractions (dissolved and particulate) along the river continuum of the middle Garonne as soon as accross the Malause reservoir. This dam represents the last hydrological discontinuity along the river continuum. Our results show that, over all the hydrological periods, the river continuum of the middle Garonne is an important sink for suspended matters, POC and PON, while it is a source for phytoplankton. Chla and dissolved silica are stored during the low water periods and remobilized during the high flows. TDP only shows important remobilizing downstream from the urban agglomeration of Toulouse. Retentions of matters during the high water periods take place along the river continuum in meanders and in areas covered by dense riparian vegetation. During low water periods, retentions are due to biological uptakes (vegetation, phytoplankton, biofilm, bacteria ). Adsorption processes on periphyton-sediment complexes are also responsible for storage of some elements, particularly phosphorus. Exportations towards the macroporous riverine environment also contribute to matter storage (TSM, DOC). The phytoplanctonic production remains very low along the river continuum. It is supplied to the Garonne river by benthic algae drift which could be produced by biofilm. Nevertheless, the main phytoplankton production originates from the different tributaries. The isotopic signatures ( 13C) of organic matters (POC, DOC) carried by the Garonne river show very few differences between the different hydrological periods. On the opposite, nitrogen isotopic signatures ( 15N) exhibit a strong enrichment during the low water periods on the different tributaries. This 15N increase is due to a high microbial activity which is responsible for biodegradation of nitrogen from sewage effluents. Specific surface areas of Garonne river bottom sediments are very low compared to other world rivers (Amazon, Mississippi) because of low clay contents in the Garonne bottom sediments. These low clay contents did not allow us to put in evidence a relationship between POC content and specific surface areas. The Malause reservoir shows on a yearly basis retentions of TSM, POC, phytoplankton, Chla and phosphorus, contrary to the river continuum, and, to a lesser extend, of dissolved silica. We can observe a low remobilizing of DOC and TDN. In the reservoir, the phytoplankton is mainly supplied by the Tarn tributary. Even if we can observe a net Chla production within the reservoir during low water periods, we never found specific phytoplanctonic species in the reservoir. Those measured during low water periods, originate from spring and summer blooms in the Tarn tributary. The Garonne contribution to the Malause reservoir phytoplankton is low and originate mainly from benthic diatoms. Whereas in the Tarn tributary, the production is rather pelagic.POC contents in the reservoir bottom sediments show a clear increase. The Malause reservoir represents a discontinuity which is trapping the POC, contrary to other sediment deposition areas like estuaries and deltas in which POC is partly mineralized. Carbon and nitrogen isotopic signatures exhibit a sequence of sediment deposits (13C impoverished and 15N enriched, and vice versa), showing an overlapping of sedimentary materials from different origins (soil erosion, phytoplankton production). It corresponds also to a mixed influence of Garonne and Tarn river contributions to the sedimentary deposits of Malause reservoirLes fleuves sont à l'origine des transferts de matières organiques et inorganiques des continents vers les océans. Ces matières peuvent être séparées par filtration (généralement à 0,45 ou 0,22 m) entre une phase particulaire et une phase dissoute. Le devenir des formes organiques va dépendre de leurs origines. Les formes labiles sont souvent rapidement minéralisées lors de leur transfert tandis que les formes réfractaires ont un comportement conservatif. Nous avons étudié la dynamique de toutes les formes (dissoutes et particulaires) de matières organiques et inorganiques le long du continuum fluvial de la Garonne moyenne ainsi que dans la retenue de Malause. Cette retenue constitue la dernière discontinuité hydrologique sur le continuum fluvial. Nos résultats montrent que le continuum fluvial de la Garonne moyenne est un important puits de matières en suspension, COP, NOP et une source de phytoplancton, toutes périodes hydrologiques confondues. Chla et silice dissoute sont stockées en périodes de basses eaux et remobilisées en périodes de hautes eaux. Seul le phosphore total dissous montre une forte remobilisation à l'aval de l'agglomération toulousaine. Les rétentions de matières ont lieu en hautes eaux sur le continuum au niveau des méandres et dans les zones couvertes de végétation riparienne dense. En étiage les rétentions sont dues à la consommation biologique (végétation, phytoplancton, biofilm, bactéries, ). Les phénomènes d'adsorption sur le complexe périphyton-sédiments sont également responsables du stockage de certains éléments, notamment le phosphore. Des exportations vers le milieu macroporeux du fleuve contribuent également aux stockages de matières (MES, COD). La production phytoplanctonique reste faible sur le continuum fluvial. Elle est apportée sur la Garonne par la dérive des algues benthiques qui pourraient provenir du biofilm. L'essentiel de la production du phytoplancton est cependant apportée par les affluents. Les signatures isotopiques ( 13C) des matières organiques (COD, COP) transportées par la Garonne montrent une très faible différence entre les périodes hydrologiques. Les signatures isotopiques de l'azote ( 15N) montrent par contre un très fort enrichissement en étiage au niveau des affluents. Cet enrichissement traduit une forte activité microbienne qui est à l'origine d'une biodégradation de l'azote issu des rejets anthropiques. L'analyse des surfaces spécifiques des sédiments de fond du continuum montre que la Garonne possède des surfaces faibles par rapport à d'autres fleuves du monde (Amazone, Mississipi) du fait des teneurs faibles en argiles dans ses sédiments de fond. Ces faibles teneurs en argiles n'ont pas permis de mettre en évidence de relation entre les teneurs en COP et les surfaces spécifiques. La retenue de Malause montre à l'échelle annuelle une rétention de MES, COP, phytoplancton, Chla et phosphore, contrairement au continuum fluvial, et dans une moindre mesure, de la silice dissoute. On observe une faible remobilisation de COD et NTD. Le phytoplancton de la retenue est apporté principalement par le Tarn, bien que nous observions une nette production de Chla en étiage dans la retenue, nous n'avons pas trouvé d'espèces spécifiques à la retenue. Celles qui se développent en basses eaux sont issues des blooms printanier et estival du Tarn. La contribution de la Garonne au phytoplancton de Malause est faible et vient des diatomées essentiellement benthiques alors que le Tarn montre une production plutôt pélagique. Les teneurs en COP des sédiments de fond de la retenue montrent une nette augmentation. On est donc dans le cas d'une discontinuité qui piège le COP contrairement à d'autres zones d'accumulation de sédiments tels les estuaires ou les deltas où le COP est en partie minéralisé. L'étude des signatures isotopiques du carbone et de l'azote montre une succession de dépôts sédimentaires (appauvris en 13C et enrichis en 15N puis l'inverse), mettant en évidence une superposition de matériaux d'origines différentes (érosion des sols, production phytoplanctonique). Cette succession traduit aussi la double influence de la Garonne et du Tarn sur les dépôts sédimentaires de la retenue de Malause.TOULOUSE-ENSAT-Documentation (315552324) / SudocSudocFranceF
Integrated approach to the physico-chemical conditions affecting the biological components in the fluvial section of the Gironde estuary
No full textLes estuaires, situés à l’interface entre les domaines continental et marin, constituent des zones essentielles dans les échanges de matières. Ils jouent dès lors un rôle capital pour les cycles biogéochimiques et biologiques et subissent, par ailleurs, des pressions climatiques et anthropiques croissantes depuis plusieurs décennies. Le présent travail a été focalisé sur les peuplements benthiques et pélagiques présents dans la partie fluviale (Garonne et Dordogne) de l’estuaire de la Gironde, zone àtrès faible salinité où ces peuplements n’avaient encore jamais été étudiés. Alors que la méiofaune, composée principalement de Nématodes, s’est avérée relativement abondante dans les domaines intertidal et subtidal, le macrobenthos est apparu composé essentiellement d’Oligochètes en intertidal et complètement absent en subtidal. La grande plasticité du copépode dominant Eurytemora affinis a été confirmée, celui-ci occupant une niche écologique différente dans la partie fluviale de l’estuaire par rapport à la zone haline. L’importance de la température plutôt que la qualité du pool nutritif sur la productivité d’E. affinis a été démontrée, mettant en évidence une fois de plus la grande adaptabilité de cette espèce dans un habitat très fluctuant. L’étude de l’habitat benthique et pélagique, notamment en terme de qualité du pool nutritif disponible pour les organismes, a démontré que la contribution de la matière organique réfractaire d’origine terrestre est dominante. La contribution du micro phytobenthos à la composition de la matière organique sédimentaire et pélagique a aussi été mise en évidence. Enfin,l’étude des communautés planctoniques dans la partie fluviale de l’estuaire de la Gironde a montré que l’espèce E. affinis y occupe une position clef.Being at the interface between continental and marine systems, estuaries are essential areas for matter exchanges. Therefore, they play a crucial role in biological and biogeochemical cycles. In addition to natural fluctuations, these systems have also undergone increasing climate and anthropogenic pressures for several decades. The present work focused on the benthic and pelagic assemblages in the fluvial section (Garonne and Dordogne rivers) of the Gironde estuary, a low salinity area where these communities had never been studied. Meiofauna, mainly composed ofnematodes, was found in relatively high abundance in both intertidal and subtidal zones.Macrozoobenthos was essentially composed of oligochaetes in the intertidal, while it was totally absent in the subtidal areas. The high plasticity of the dominant copepod Eurytemora affinis was confirmed, with a different ecological niche in the freshwater section of the estuary compared to the haline area downstream. The importance of temperature rather than the quality of the nutrient pool on the productivity of E. affinis was demonstrated, thereby confirming the great adaptability of thisspecies to a highly fluctuating habitat. Study of benthic and pelagic habitat, especially in terms of quality of the nutrient pool available to the organisms, showed that the contribution of refractoryorganic matter with a terrestrial origin is dominant. A significant contribution of microphytobenthos to the composition of sedimentary and pelagic organic matter was also highlighted. Finally, the study of planktonic communities in the fluvial part of the Gironde estuary showed that the species E. affinis occupies a key position in this part of the estuary
The predation impact of juvenile herring Clupea harengus and sprat Sprattus sprattus on estuarine zooplankton
No full textThe consumption of estuarine copepods by juvenile herring and sprat during estuarine residency was estimated using fish biomass data and daily rations calculated from two models of feeding in fish: a bioenergetic model and a gastric evacuation model. The bioenergetic model predicted daily rations that were, on average, three times higher than those estimated by a model based on field records of stomach contents. The biomass of herring and sprat in the estuary was negatively correlated with the daily ration suggesting that the clupeid fish populations were resource-limited. Copepod production decreased towards the winter and peaked in spring and summer. The relative importance of predation changed seasonally in function of the migration pattern of herring and sprat. In the spring and the summer, in situ production of␣copepod biomass was higher than the in situ consumption by fish. During the fall and the winter, consumption exceeded production. This suggests that top–down control exerted by marine pelagic fish may be an important force structuring estuarine copepod populations
Hourly Matching of renewable electricity production with demand of large-scale electricity consumers
No full textThis research aims to provide a method for large-scale commercial electricity consumers to procure towards 100% hourly matched renewable electricity. A problem with the current electricity balancing system is that the energy produced by Variable Renewable Energy sources (VRES), such as wind and solar PV, has a weather-dependent production profile and is thus non-controllable and intermittent. The balance between the total energy demand of the large-scale electricity (LSE) consumer and the production of electricity from VRES in their contract is only based on a yearly scale and not on an hourly scale. At moments when there is little wind, mainly coal & gas- powered plants need to be dispatched to secure uninterrupted power supply. Procurement of renewable energy is realized with the use of Guarantees of origin (GOs). GOs are an instrument that tracks the origin of electricity generated from renewable resources on a yearly basis but does not differentiate in hourly production profile. Therefore, this system will not be able to address the challenge of balancing VRES and demand on an hourly scale. In the future, with the ambition of moving towards substantially higher proportion of RES, the balancing on hourly base is needed to decrease the dependency on the conventional plants as backup. Therefore, with the current setup with yearly tracked RES, companies are limited in their role in the energy transition. This research aims to provide a novel method for large-scale commercial electricity consumers to procure towards 100% hourly matched renewable electricity. In this thesis, a techno-economic analysis was conducted to examine possible hourly-matched renewable energy portfolio for Dutch LSE consumers. First, an analysis was conducted of the production and storage technologies that could potentially be used for the application of hourly matching. Secondly, a methodology was developed to analyse the match between an LSE consumer’s demand and the production profile. The degree to which these profiles are matched was defined as the green score. The higher the green score, the higher the percentage of the demand that is covered by the portfolio on an hourly base. The demand profile is kept consistent, and a comparison is made of scenarios of different portfolios containing production and storage technologies. Third, using a Levelised Cost of Portfolio (LCOP) the cost per MWh for the whole portfolio is compared for different scenario’s. This study shows that the hourly match measured using the percentage green score can be significantly increased by adapting the LSE consumer portfolio, however a 100% hourly match is not shown. Much of the research to date has focused on national-scale scenarios, but only provides limited incentives and insights into the role that large companies can play. This study provides a tool which is suitable to perform a techno-economic analysis to increase the hourly match of LSE consumers using various electricity production and electrical energy storage technologies. The insights found on the impact of different combinations of technologies in a portfolio can be used to understand a further possible role of these companies in the energy transition.Industrial Ecolog
Genetics of the estuarine copepod Eurytemora affinis with regard to improving water quality
No full textAbstract: As an estuary being restored, the Scheldt (Belgium/The Netherlands) offers an interesting setting to study the response of organisms and ecosystems to changing conditions. In this regard, this study specifically deals with the spatio-temporal distribution and possible genetic differentiation among the species complex Eurytemora affinis (Copepoda, Calanoida). Until the 1990s, E. affinis typically occurred downstream the estuary. In parallel to water quality improvement, E. affinis since recently also occurs upstream in the estuary and in some of the tributaries. In a former study, Gasmi et al. (2014), found little genetic differentiation between the upstream population and downstream one, which is probably at the origin of the upstream population. However, surprisingly, two different genetic entities of the E. affinis complex were present: one in the main stream of the Scheldt estuary and one in its tributaries. This present work aims at understanding how independent tributaries, situated at opposite sides of the estuary, can host a single genetic entity while another one is present only in the main estuary. A dense sampling in the main stream and the two main tributaries was made in May 2014 (12 locations) and four ISSR primers producing 78 polymorphic loci were used to perform a molecular analysis. Bayesian and hierarchical analysis revealed that the results are more mixed and the different genetic entities are less well delimited than reported in our former study based on samples collected in 2012. A genetical mix between tributary and upstream populations is now observed. This suggests that a homogenization process of the E. affinis populations is in progress in parallel to the improvement of water quality. These results are discussed and several explanations are proposed
Selective feeding of bdelloid rotifers in river biofilms.
No full textIn situ pigment contents of biofilm-dwelling bdelloid rotifers of the Garonne River (France) were measured by high performance liquid chromatography (HPLC) and compared with pigment composition of surrounding biofilm microphytobenthic communities. Among pigments that were detected in rotifers, the presence of carotenoids fucoxanthin and myxoxanthophyll showed that the rotifers fed on diatoms and cyanobacteria. Unexpectedly, while diatoms strongly dominated microphytobenthic communities in terms of biomass, HPLC results hinted that rotifers selectively ingested benthic filamentous cyanobacteria. In doing so, rotifers could daily remove a substantial fraction (up to 28%) of this cyanobacterial biomass. The possibility that the rotifers hosted symbiotic myxoxanthophyll-containing cyanobacteria was examined by localisation of chlorophyll fluorescence within rotifers using confocal laser scanning microscopy (CLSM). CLSM results showed an even distribution of quasi-circular fluorescent objects (FO) throughout rotifer bodies, whereas myxoxanthophyll is a biomarker pigment of filamentous cyanobacteria, so the hypothesis was rejected. Our results also suggest that rotifers converted β-carotene (provided by ingested algae) into echinenone, a photoprotective pigment. This study, which is the first one to detail in situ pigment contents of rotifers, clearly shows that the role of cyanobacteria as a food source for meiobenthic invertebrates has been underestimated so far, and deserves urgent consideration
Mindfulness training for smoking cessation in adults participating in Alcoholics Anonymous
No full textPurpose: Smoking is the leading cause of preventable disease. Smokers die an average of ten years earlier than individuals who do not smoke. Over 34 million adults in the United States smoke. The goal of this study is to use mindfulness training to increase smoking cessation rates.
Methods: This quality improvement study examined the effectiveness of mindfulness training exercises and smoking cessation rates in adults who attended an alcoholics anonymous meeting in Central New Jersey. Participants completed a pre-test and were then taught how to use mindfulness training exercises when the urge to smoke a cigarette arises. After four weeks of using mindfulness training, the same participants completed a post-test to examine whether mindfulness training exercises aided in smoking cessation.
Results: This study showed that the mean number of cigarettes smoked in a day decreased from 17.5 to 14.77 (n=44, p=<0.001, 95% CI) after mindfulness training exercises were used. There was a 15.58% change in the number of cigarettes smoked after using the mindfulness training exercises. 70.4% of participants in this study found mindfulness training helpful in smoking cessation.
Implications: This study showed a statistically significant reduction in the number of cigarettes smoked after mindfulness training exercises. Mindfulness training was more effective with individuals who have smoked for five years or less. Habit and stress were shown to be the main reasons why individuals in this study smoked. There was no correlation between living with a smoker and cessation rates.D.N.P.Includes bibliographical reference
Struggles with empathy and optimal responsiveness : an intersubjective view
No full textIncludes bibliography.This dissertation reviews the psychotherapeutic techniques of empathy and optimal responsiveness from within a Self Psychology framework. Self Psychologists view these techniques as essential for the activation of the selfobject experience, the core requirement for the restoration of a cohesive sense of self. However, numerous factors arising in the therapeutic situation mitigate against empathic listening, and there is no real consensus amongst Self Psychologists about what constitutes an optimal response. This presents a particular difficulty for trainee therapists who seek guidelines in how to use these techniques. This dissertation aims to demonstrate that empathy and optimal responsiveness are inextricably bound up with the intersubjective field, an inclusive system of which each individual is a part. A psychoanalytically informed clinical study of the intersubjective field is used to illustrate this notion. Through analysis of the patient's responses and the therapist's countertransference responses, it is shown that empathy and optimal responsiveness arise from the interface between the subjective experiences of both therapist and patient and thus include the dynamics of both. Retrospective analysis which has enabled the author to grow as a psychotherapist, is highlighted, with the hope that this may be useful to future trainee therapists
