Dissertations / Theses on the topic 'Poplar Clones'

Thesis (M.S.)--University of Missouri-Columbia, 2006.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (February 7, 2007) Includes bibliographical references.

The interest in renewables for energy has increased in the last 2-3 decades because of the negative environmental impact caused by the burning of fossil fuels, the raising prices of traditional fuels, the dependence on foreign oil, and the decrease in fossil fuels resources. Biomass energy represents one of the most promising alternatives. Many studies worldwide were devoted to investigate growth and yield of short rotation forestry plantations for energetic use and several empirical and process-based models were developed to predict the potential production of biomass. The current work was concentrated on modelling site productivity (potential of biomass production) of specific poplar clones planted on arable Saxon land under different stocking densities. Empirical data collected from several experimental areas were used. Site productivity has been predicted depending on stand age and site variables using a two-step model. In step one age and site variables were used to model stand dominant height and in step two the constructed dominant height was involved with stocking density to predict stand oven dried biomass. Depending on data availability the model was parameterized for four different groups of poplar clones: Androscoggin (clone Androscoggin), Matrix (Matrix and hybrid 275), Max (Max 1 …Max 5) and Münden (clone Münden). Both stand dominant height and stand dry biomass were modelled for ages 2 – 9 years for clone groups: Matrix and Max and for ages 2 – 7 years for clone groups: Androscoggin and Münden. The model has been tested and validated using several statistical and graphical methods. The relative bias (ē %) in the dominant height estimates ranged between 0.5 % > ē % > - 0.5 % in all clone groups and had a maximum bias of 10.41 % in stand biomass estimates. Model accuracy (mx %) in the dominant height estimates ranged between 12.25 and 17.56 % and between 8.05 and 27.32 % in stand biomass estimates. Two different scenarios were presented to show the potential of biomass that can be produced from poplar plantations on arable and former fallow Saxon lands at different stocking densities. ArcGIS has been used to visualize model application results. In order to produce a mean annual increment ≥ 8 [dry t/ha/a] from poplar plantations (Max group) for more than 50 % of arable or former fallow lands in the first rotation at least 9 years are required under stocking density of 4000 stems/ha and 7 years for both stocking densities 8333 and 10,000 stems/ha
Die Nachfrage nach Holz für energetische Zwecke nimmt in Deutschland und ganz Europa zu. Um diesen Bedarf künftig besser befriedigen zu können, müssen verstärkt Ressourcen aus verschiedenen Quellen wie z. B. Holz aus Niederwäldern oder Durchforstungsreserven im Hochwald mobilisiert und ergänzend Holz in Kurzumtriebsflächen produziert werden (Guericke, M. 2006). Ziel dieser Arbeit war es, das Ertragspotential von Pappelklonen in Kurzumtriebsplantagen unterschiedlicher Baumdichte auf sächsischen Ackerflächen zu untersuchen. Hierzu wurden die potentiellen Erträge anhand empirischer, auf verschiedenen Versuchsflächen erhobener Daten modelliert. Zur Schätzung des Ertragspotentials wurde ein zweistufiges Modell entwickelt: Im ersten Schritt erfolgte die Modellierung der Oberhöhe eines Bestandes (ho, m) in Abhängigkeit von Bestandesalter und Standortfaktoren unter Verwendung einer multiplen linearen Regressionsanalyse, dabei wurden Bestimmtheitsmaße (R²) von 0,975 bis 0,989 erreicht. In einem zweiten Schritt lässt sich dann der Biomassevorrat [tatro/ha/a] mittels nichtlinearer Regressionsanalyse durch die Bestandesoberhöhe schätzen. Das Bestimmtheitsmaß von R² ≥ 0,933 weist auch hier auf eine hohe Anpassungsgüte hin. Die Modellparametrisierung erfolgte für folgende vier Gruppen von Pappelklonen: • Max-Gruppe: Klone Max 1, Max 2, Max 3, Max 4 und Max 5, Altersbereich 2 – 9 Jahre, Baumdichten von 1150 – 13000 Stämmen/ha; • Matrix-Gruppe: Klon Matrix und Hybride 275, Altersbereich 2 – 9 Jahre, Baumdichte 1550 Stämme/ha; • Androscoggin-Gruppe: Klon Androscoggin, Altersbereich 2 – 7 Jahre, Baumdichte 1550 Stämme/ha; und • Münden-Gruppe: Klon Münden, Altersbereich 2 – 7 Jahre, Baumdichte 1550 Stämme/ha. Die Güte des Modells wurde mit Hilfe verschiedener statistischer Verfahren überprüft. Bei der Validierung anhand des Datensatzes, welcher für die Modellkonstruktion Verwendung fand, zeigte das Modell eine Verzerrung bzw. einen Bias von 0,5 % > ē % > - 0,5 % bei der Bestandesoberhöhenschätzung und einen maximalen Bias von 10,41 % bei der Schätzung der Bestandesbiomasse. Die Treffgenauigkeit (mx %) des Modells hingegen variierte zwischen 12,25 % und 17,56 % bzw. 8,05 und 27,32 % (bei Schätzung der Bestandesoberhöhe bzw. der Bestandesbiomasse). Zudem wies das Modell keinen systematischen Fehler zwischen den geschätzten und den realen Werten auf. Bei der Validierung mit einem unabhängigen Datensatz betrug die Treffgenauigkeit (mx %) für die Schätzung der Bestandsoberhöhe und des Biomassevorrates 15,72 bzw. 26,68 %. Um das Ertragspotenzial von Pappelplantagen für die gesamte sächsische Ackerfläche bzw. die gesamte ehemalige Stilllegungsfläche zu bestimmen, wurden die zu Schätzung erforderlichen Standortvariablen auf Gemeindebasis kalkuliert, mittels ArcGIS dargestellt sowie Simulationsrechungen für verschiedene Bestandsdichten vorgenommen und ebenfalls visualisiert. Den Ergebnissen der Simulationsrechnungen zufolge wäre bei einer Stammzahl von 4000 N/ha eine Rotationslänge von 9 Jahren, bei 8333 bis 10.000 N/ha von 7 Jahren erforderlich, um einen durchschnittlichen Gesamtzuwachs (dGz) von ≥ 8 [tatro/ha/a] auf mehr als 50 % der sächsischen Ackerflächen bzw. ehemaligen Stilllegungsflächen in erster Rotation zu erreichen. Würde die gesamte ehemalige sächsische Stilllegungsfläche mit einer Baumdichte von 10.000 Stämmen/ha bepflanzt werden, könnten Pappelplantagen im Alter 9 einen dGz von 520.000 [tatro/a] (entsprechend 250.000 Kubikmeter Diesel) erreichen. Bei Bestockung aller sächsischen Ackerflächen würde sich der Ertrag auf bis zu 9.087.000 [tatro/a] (entsprechend 4.367.000 Kubikmeter Diesel) erhöhen

The interest in renewables for energy has increased in the last 2-3 decades because of the negative environmental impact caused by the burning of fossil fuels, the raising prices of traditional fuels, the dependence on foreign oil, and the decrease in fossil fuels resources. Biomass energy represents one of the most promising alternatives. Many studies worldwide were devoted to investigate growth and yield of short rotation forestry plantations for energetic use and several empirical and process-based models were developed to predict the potential production of biomass. The current work was concentrated on modelling site productivity (potential of biomass production) of specific poplar clones planted on arable Saxon land under different stocking densities. Empirical data collected from several experimental areas were used. Site productivity has been predicted depending on stand age and site variables using a two-step model. In step one age and site variables were used to model stand dominant height and in step two the constructed dominant height was involved with stocking density to predict stand oven dried biomass. Depending on data availability the model was parameterized for four different groups of poplar clones: Androscoggin (clone Androscoggin), Matrix (Matrix and hybrid 275), Max (Max 1 …Max 5) and Münden (clone Münden). Both stand dominant height and stand dry biomass were modelled for ages 2 – 9 years for clone groups: Matrix and Max and for ages 2 – 7 years for clone groups: Androscoggin and Münden. The model has been tested and validated using several statistical and graphical methods. The relative bias (ē %) in the dominant height estimates ranged between 0.5 % > ē % > - 0.5 % in all clone groups and had a maximum bias of 10.41 % in stand biomass estimates. Model accuracy (mx %) in the dominant height estimates ranged between 12.25 and 17.56 % and between 8.05 and 27.32 % in stand biomass estimates. Two different scenarios were presented to show the potential of biomass that can be produced from poplar plantations on arable and former fallow Saxon lands at different stocking densities. ArcGIS has been used to visualize model application results. In order to produce a mean annual increment ≥ 8 [dry t/ha/a] from poplar plantations (Max group) for more than 50 % of arable or former fallow lands in the first rotation at least 9 years are required under stocking density of 4000 stems/ha and 7 years for both stocking densities 8333 and 10,000 stems/ha.
Die Nachfrage nach Holz für energetische Zwecke nimmt in Deutschland und ganz Europa zu. Um diesen Bedarf künftig besser befriedigen zu können, müssen verstärkt Ressourcen aus verschiedenen Quellen wie z. B. Holz aus Niederwäldern oder Durchforstungsreserven im Hochwald mobilisiert und ergänzend Holz in Kurzumtriebsflächen produziert werden (Guericke, M. 2006). Ziel dieser Arbeit war es, das Ertragspotential von Pappelklonen in Kurzumtriebsplantagen unterschiedlicher Baumdichte auf sächsischen Ackerflächen zu untersuchen. Hierzu wurden die potentiellen Erträge anhand empirischer, auf verschiedenen Versuchsflächen erhobener Daten modelliert. Zur Schätzung des Ertragspotentials wurde ein zweistufiges Modell entwickelt: Im ersten Schritt erfolgte die Modellierung der Oberhöhe eines Bestandes (ho, m) in Abhängigkeit von Bestandesalter und Standortfaktoren unter Verwendung einer multiplen linearen Regressionsanalyse, dabei wurden Bestimmtheitsmaße (R²) von 0,975 bis 0,989 erreicht. In einem zweiten Schritt lässt sich dann der Biomassevorrat [tatro/ha/a] mittels nichtlinearer Regressionsanalyse durch die Bestandesoberhöhe schätzen. Das Bestimmtheitsmaß von R² ≥ 0,933 weist auch hier auf eine hohe Anpassungsgüte hin. Die Modellparametrisierung erfolgte für folgende vier Gruppen von Pappelklonen: • Max-Gruppe: Klone Max 1, Max 2, Max 3, Max 4 und Max 5, Altersbereich 2 – 9 Jahre, Baumdichten von 1150 – 13000 Stämmen/ha; • Matrix-Gruppe: Klon Matrix und Hybride 275, Altersbereich 2 – 9 Jahre, Baumdichte 1550 Stämme/ha; • Androscoggin-Gruppe: Klon Androscoggin, Altersbereich 2 – 7 Jahre, Baumdichte 1550 Stämme/ha; und • Münden-Gruppe: Klon Münden, Altersbereich 2 – 7 Jahre, Baumdichte 1550 Stämme/ha. Die Güte des Modells wurde mit Hilfe verschiedener statistischer Verfahren überprüft. Bei der Validierung anhand des Datensatzes, welcher für die Modellkonstruktion Verwendung fand, zeigte das Modell eine Verzerrung bzw. einen Bias von 0,5 % > ē % > - 0,5 % bei der Bestandesoberhöhenschätzung und einen maximalen Bias von 10,41 % bei der Schätzung der Bestandesbiomasse. Die Treffgenauigkeit (mx %) des Modells hingegen variierte zwischen 12,25 % und 17,56 % bzw. 8,05 und 27,32 % (bei Schätzung der Bestandesoberhöhe bzw. der Bestandesbiomasse). Zudem wies das Modell keinen systematischen Fehler zwischen den geschätzten und den realen Werten auf. Bei der Validierung mit einem unabhängigen Datensatz betrug die Treffgenauigkeit (mx %) für die Schätzung der Bestandsoberhöhe und des Biomassevorrates 15,72 bzw. 26,68 %. Um das Ertragspotenzial von Pappelplantagen für die gesamte sächsische Ackerfläche bzw. die gesamte ehemalige Stilllegungsfläche zu bestimmen, wurden die zu Schätzung erforderlichen Standortvariablen auf Gemeindebasis kalkuliert, mittels ArcGIS dargestellt sowie Simulationsrechungen für verschiedene Bestandsdichten vorgenommen und ebenfalls visualisiert. Den Ergebnissen der Simulationsrechnungen zufolge wäre bei einer Stammzahl von 4000 N/ha eine Rotationslänge von 9 Jahren, bei 8333 bis 10.000 N/ha von 7 Jahren erforderlich, um einen durchschnittlichen Gesamtzuwachs (dGz) von ≥ 8 [tatro/ha/a] auf mehr als 50 % der sächsischen Ackerflächen bzw. ehemaligen Stilllegungsflächen in erster Rotation zu erreichen. Würde die gesamte ehemalige sächsische Stilllegungsfläche mit einer Baumdichte von 10.000 Stämmen/ha bepflanzt werden, könnten Pappelplantagen im Alter 9 einen dGz von 520.000 [tatro/a] (entsprechend 250.000 Kubikmeter Diesel) erreichen. Bei Bestockung aller sächsischen Ackerflächen würde sich der Ertrag auf bis zu 9.087.000 [tatro/a] (entsprechend 4.367.000 Kubikmeter Diesel) erhöhen.

Cilj ove doktorske disertacije predstavljalo je ispitivanje uticaja vodnog stresa izazvanog  sa polietilen glikolom (PEG)  6000 na biohemijske osobine klonova topole. Reznice tri klona topole (M-1, B-229 i PE19/66) su hidroponski gajene i izložene 100 mOsm i 200 mOsm PEG 6000  tokom šest dana. Nakon tretmana u kontrolnim i stresiranimbiljkama su  ispitane promene aktivnosti antioksidantnih enzima,  aktivnost dvaenzimska markera polifenolnog metabolizma, fenolni profil, antioksidantna aktivnost, kao i sadržaj prolina i glicin betaina  (GB). Takođe, ispitan je biohemijski odgovor kulture tkiva klona M-1 na vodni stres izazvan sa PEG 6000.U oba eksperimenta uočeno je da je akumulacija prolina i GB u uslovima vodnog stresa izazvanog sa PEG 6000 najvažnija strategija u otpornosti na stres i prevazilaženju vodnog deficita, tako da se ovi parametri mogu definisati kao najbolji indikatori otpornosti topole na sušu.Rezultati ovog istraživanjaupotpunjavaju saznanja o povezanosti oksidativnog stresa uzrokovanog vodnim stresom sa antioksidantnim odgovorom, nivoom oštećenja lipida i proteina, uključivanjem osmolita kao i promenama u polifenolnom profilu. Takođe, dobijeni rezultati su značajni za odabir klonova topola tolerantnih na vodni stres  i  zapošumljavanje sušnih staništa, kojih će biti sve više usled negativnog uticaja klimatskih promena.
The aim of presented doctoral thesis was investigation of the impact of water deficit caused by polyethylene glycol (PEG) 6000 on biochemical features of poplar clones.  During six days, cuttings of three poplar clones (M-1, B-229 and PE 19/66) were grown in hydroponics and subjected to 100 and 200 mOsm PEG 6000. Changes in the activity of antioxidant enzymes, polyphenol characterization, two enzymatic markers of polyphenol metabolism, antioxidant capacity, as well as proline and glycine betaine content were investigated in stressed plants. Furthermore,  assessment of  biochemical response of poplar clone M-1 tissue culture to water stress induced by PEG 6000 was performed.In both experiments, the most important strategy for stress resistance and overcoming water deficiency was accumulation of proline and glycine betaine so these parameters can be defined as the best indicators of poplar resistance to drought.The results of this study complete  the findings on the oxidative stress caused by water stress  and their relationship with the antioxidant response, the level of lipid andprotein damage, accumulation of the osmolites and changes in the polyphenol profile. Also, the obtained results may be important for the selection of poplar clones resistant to water stress and for afforestation in arid sites, which appeared to be more numerous due to the effects of  global climate change.

    U radu je ispitan uticaj vodnog deficita na fiziološke osobine klonova crne topole ipopulacija hrasta lužnjaka i cera, kao i mogućnost oporavka ovih biljaka nakon ponovnog uspostavljanja optimalnog vodnog režima. Cilj istraživanja je bio da se ukaže na potencijal ispitivanih genotipova topole i hrastova za opstanak u  promenljivim uslovima životne sredine, u skladu sa aktuelnim klimatskim promenama koje uključuju smanjenje količine padavina i ograničenu dostupnost vode. Dobijeni rezultati su pokazali specifično variranje ispitivanih morfo-anatomskih, fizioloških i biohemijskih parametara koje je zavisilo od momentalne vlažnosti zemljišta na primenjenom tretmanu (kontrola, suša praćena oporavkom, konstantna suša) i od genotipa biljke.    Negativan uticaj vodnog  deficita na tretmanu konstantne suše je u najmanjoj meri bio ispoljen na rastenje klona topole X/32, populaciju hrasta lužnjaka L1 i populaciju hrasta cera C1. Indeks tolerancije na stres izračunat na osnovu visine biljke (PHSI) takodje je potvrdio dobru morfološku prilagodjenost pomenutih genotipovana uslove suše. Dobijene vrednosti indeksa stoma ukazuju da vodni status ispitivanih populacija hrastova nije bio naroĉito pogodjen vodnim deficitom na sušnim tretmanima.    Tretman konstantne suše je u oba ogleda  doveo do najvećeg smanjenja vrednostiparametara razmene gasova kod skoro svih genotipova. S druge strane, primenjeni sušni tretmani nisu uslovili smanjenje sadržaja fotosintetiĉkih pigmenata, kao ni parametra Fv/Fm, kod većine ispitivanih biljaka. U odnosu na kontrolu, sadržaj prolina u listovima ispitivanih biljaka na tretmanu konstantne suše bio je    znaĉajno povećan, a aktivnost enzima nitrat-reduktaze značajno smanjena, kod većine genotipova.    Genotipovi kod kojih u uslovima jakog vodnog deficita nije došlo do značajne promene većine ispitivanih morfo-anatomskih, fizioloških i biohemijskih parametara mogu biti od velike važnosti kad je u pitanju njihov odabir i upotreba za uspešno pošumljavanje sušnih staništa, kojih će biti sve više usled negativnog uticaja brojnih ekoloških činilaca nastalih kao posledica klimatskih promena.
The impact of water deficit and recovery on physiological features of the black poplar clones, as well as of the oaks populations were analyzed. The aim of this research was to indicate the potential of the studied genotypes for survival under changing environmental conditions, in accordance with current climate changes, which include the reduction in amount of rainfall and limited water availability. Obtained results have shown a specific variation of studied morpho-anatomical, physiological and biochemical parameters which depended on soil humidity on the applied treatment (control, drought followed by recovery and permanent drought), as well as on plant genotype.Water deficit on permanent drought treatment had little negative effect on plant growth of poplar clone X/32, as well as oak populations L1 and C1. Plant height stress tolerance index also confirmed good morphological adaptation to drought of these genotypes. Stomatal index was not negatively affected by water deficit in oak plants.     In both experiments, a permanent drought treatment led to the largest reduction in the values of gas exchange parameters in almost all genotypes.On the other hand, concentration of  photosynthetic pigments was not considerably decreased in plants exposed to water deficit, as well as the parameter Fv/Fm, in most examined plants. Compared to the control, the impact of permanent drought treatment  on biochemical parameters was expected, in the most cases.     Compared to the control, proline content in leaves of most examined genotypes was significantly increased on permanent drought treatment, while nitrate reductase activity was significantly decreased.Examined genotypes exhibiting slight or no reduction in values of the most  examined parameters during severe  drought stress, could be used for afforestation in arid sites. Arid habitats appeared to be more numerous due to the effects of global climate changes.

Thesis (M.S.) -- University of Maryland, College Park, 2009.
Thesis research directed by: Dept. of Biological Resources Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

The aim of this thesis is to identify and illuminate Anyurus fictional portrayal of Islam and Muslims role in the future Swedish society. Furthermore, this thesis intends to shed light on the novels attitudes towards Islam and Muslims. This thesis hopes to add knowledge about how Islam and Muslims can be portrayed in popular cultural. The research questions are framed as follow: How can portrayal of Islam and Muslims in Anyurus novel be understood in relation to José Casanovas theory of the changing role of religions in the public and private spheres? Does Anyurus novel reflect open or closed attitudes about Islam and Muslims? The theoretical starting points that were used to answer the study’s purpose and research questions were José Casanovas secularization theory and The Runnymede Trust model of open and closed attitudes towards Islam and Muslims. The methodological approach was a qualitative content analysis with a focus on a thematic analysis. The material that was being analyzed is a novel called They will drown in their mother’s tears, written by Johannes Anyuru. The results showed that José Casanovas secularization theory could be used to understand Islam and Muslims role in the society. Results showed that their role did not disappear from the public to the private sphere, it was a choice that Muslims in the novel decided by themselves. The result also showed that it can be argued that the majority of Anyurus representation reflect closed attitudes towards Islam and Muslims. The open attitudes could not be identified and reflected in Anyurus novel. It is important to keep in mind that this is a study that is based on a fictional representation of the future of Sweden, which therefore means that it is not possible to draw a parallel to reality.

L'intérêt de l'humanité pour la connaissance se joue sur deux fronts : celui de la réduction de l'ignorance, et celui de l'action tant individuelle que collective. Aussi la manière dont nous acquérons le savoir est-elle essentielle, parce qu'elle préjuge aussi bien de notre perception du monde que de notre conscience de nous-mêmes et de la société. Car si, avec la raison comme alliée, l'homme se découvre des potentialités illimitées, nous aurions pourtant tort de passe outre une stricte réalité, celle de notre ignorance infinie, celle, au fond, de notre incapacité à cerner, de façon sûre et certaine, quoi que ce soit de ce monde complexe et en évolution constante qui nous accueille. C'est pourquoi, pour Karl Popper, toute rationalité véritable doit être critique, c'est-à-dire pluraliste et débattante, seule façon de considérer objectivement l'écart qui nous sépare de la vérité et, par suite, d'agir avec prudence et discernement, dans l'intérêt de la science comme dans celui de la collectivité.

On a l’habitude, concernant Bergson et Popper, de souligner que le second emprunte au premier la notion de « société ouverte » en la détournant de son sens. C’est une erreur : au moment où il met cette notion au centre de La société ouverte et ses ennemis, Popper est persuadé d’être l’inventeur de la notion. Lorsqu’il apprend que Bergson en a fait usage avant lui, il marque la différence entre les deux sociétés ouvertes tout en reconnaissant une similitude entre les deux sociétés closes. Mais comment, si la société close s’oppose, par définition, à la société ouverte, et si les deux notions de « société close » sont similaires, les deux notions de « société ouverte » pourraient-elles être fondamentalement dissemblables ? Nous nous demandons, dans une première partie, jusqu’où les deux sociétés closes peuvent être considérées comme similaires et s’il est possible d’en construire une conception unifiée. Nous cherchons d’abord à montrer comment Bergson et Popper, en partant de problèmes différents, finissent par se rejoindre sur la notion d’une morale naturelle close. Nous montrons ensuite que ces deux modalités du clos — exclusivisme guerrier et holisme conservateur — se trouvent chez les deux auteurs, sans qu’ils ne leur accordent la même importance : un certain nombre de différences souterraines annoncent les oppositions à venir sur la société ouverte. Ces différences n’empêchent toutefois pas l’élaboration d’une conception unifiée de la société close. Nous suivons Bergson pour articuler les deux modalités du clos en considérant que la cohésion sociale trouve en partie sa source dans l’hostilité à l’égard des ennemis. Notre deuxième partie se demande si ce qui apparaît au premier abord comme contradictoire entre les deux sociétés ouvertes ne pourrait pas plutôt être considéré comme des tensions au sein d’une même société ouverte. Nous insistons d’abord sur ce qui peut apparaître comme contradictoire en montrant que l’ouverture n’a pas le même sens chez Bergson et chez Popper : passage de la cité à une société comprenant l’humanité pour le premier, passage à une cité où sont libérés les pouvoirs critiques de l’homme pour le second. La société ouverte de Popper est close pour Bergson, la société ouverte de Bergson relève pour Popper d’une nostalgie pour la société close. Mais la contradiction vient du fait qu’on compare la modalité de l’ouvert que chacun privilégie et qui n’est pas la même. Il faut, pour avoir une vision plus juste, comparer la modalité rationaliste de l’ouverture chez les deux auteurs, et la modalité mystique de l’ouverture chez l’un et chez l’autre. En procédant à cette comparaison, on peut montrer que ces deux modalités sont l’une et l’autre une façon, pour une société, de transcender la nature, d’être créatrice. En ce qui concerne la modalité rationaliste de l’ouverture, c’est Popper qui parvient à en montrer le caractère créateur, sur le plan théorique comme sur le plan pratique — Bergson en étant empêché par sa conception de l’intelligence ; pour ce qui est de la modalité mystique, c’est Bergson qui montre comment elle permet à une société de transcender, au moins partiellement, la nature — Popper en étant empêché par sa conception de l’amour. A partir de là, il ne semble pas impossible d’élaborer une conception unifiée de la société ouverte articulant ces deux modalités : la modalité rationaliste de l’ouverture repose sur la foi en la fraternité humaine, laquelle ne peut trouver son plein élan que dans la modalité mystique. Il est vrai qu’il y a tension entre ces deux modalités de l’ouvert, mais leur équilibre est nécessaire à la société qui s’ouvre : la présence de la modalité mystique évite à la modalité rationaliste, qui permet le conflit, une dégénérescence guerrière ; la présence de la modalité rationaliste évite à la modalité mystique, qui transcende les conflits dans l’enthousiasme, de dégénérer en « nationalisme mystique »
It is usually said, when talking about Bergson and Popper, that the former borrows the notion of “open society” to the latter and diverts its meaning. It is a mistake: when he puts this notion in the center of The open society and its enemies, Popper is convinced that he is the one who came up with the notion. When he learns that Bergson used it before him, he underlines the differences between both open societies, while admitting a similarity between both closed societies. But how, if the closed society opposes, by definition, the open society, and if both notions of “closed society” are similar, could both notions of “open society” be fundamentally dissimilar?We are wondering, in our first part, to what degree the two closed societies can be considered similar, and if it is possible to build a unified conception of both of them. We are first seeking to show how Bergson and Popper, while starting from different issues, end up reuniting on the notion of a closed natural morality. We are then showing that these two modalities of the closed – warrior exclusivism and conservative holism – are found in both authors, although they don’t give it the same degree of importance: a number of underlying differences are announcing the upcoming oppositions on the open society. These differences, however, do not prevent the elaboration of a unified conception for the closed society. We are following Bergson to articulate both modalities of the closed while considering that social cohesion comes partly from hostility towards enemies. Our second part questions if what first shows up as a contradiction between both open societies could not be considered rather as tensions among one same open society. We first insist on what can appear as contradictory by showing that openness doesn’t have the same meaning for Bergson it does for Popper: for the former, it’s stepping from the city to a society containing humanity. For the latter, it’s stepping to a city where man’s critical powers are liberated. Popper’s open society is closed to Bergson, and Bergson’s open society is, to Popper, an expression of the longing for the unity of the closed society. But the contradiction comes from comparing each author’s preferred modality for openness, which differs. It is necessary, to have a better vision, to compare the rationalist modality of openness for both authors, as well as the mystical modality of openness for one and the other.By proceeding to this comparison, we can show that these two modalities are both a way for a society to transcend nature, for it to be inventive or creative. When it comes to the rationalist modality of openness, Popper is the one who manages to show its creative aspect, in both theory and practice – Bergson being restrained to do so by his conception of intelligence; when it comes to the mystical modality, it is Bergson who shows how it allows a society to transcend, at least partially, nature – Popper being restrained to do so by his conception of love.From this point, it doesn’t seem impossible to elaborate a unified conception for the open society articulating both of these modalities: the rationalist modality of openness is based on faith in human fraternity, which can only reach its fullest with the mystical modality. It is true that there is tension between these two modalities of openness, but their balance is necessary for a society that opens up: the mystical modality’s presence prevents the rationalist modality, that allows conflict, to fall into warrior degeneracy; the rationalist modality’s presence prevents the mystical modality, that transcends conflicts in enthusiasm, to degenerate into “mystical nationalism”

Thesis (M.S.)--University of Wisconsin--Madison, 1995.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 88-95).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1993.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 162-172).

Effects of mineral nutrition on drought and cavitation resistance of poplars were examined in two sets of greenhouse-grown trees. First, two drought-sensitive and two drought-resistant hybrid clones of black cottonwood (Populus trichocarpa Torr. & Gray) and eastern cottonwood (P. deltoides Bartr.) were grown at three concentrations of nitrogen (N) applied factorially with two concentrations of phosphorus (P) in a sub-irrigation sand-culture system. The trees were subjected to 0, 4, 6, and 8 days of gradual drought stress before measurements of cavitation, anatomical features affecting cavitation, and nutrient mobilization during drought. High foliar concentrations of N increased cavitation compared to barely adequate concentrations, whereas high concentrations o f P decreased cavitation as measured by both hydraulic flow apparatus and dye perfusion techniques. For one test, cavitation was 48% at high N and low P, but only 28% at high N and high P. Vessel pit membrane mean pore diameters were 0.132 μm at low P and 0.074 μm at high P: smaller pores would decrease air-seeding cavitation. No other significant effects of mineral nutrition on vessel dimensions were observed. Scanning election microscopy showed less damage to pit membranes, suggesting greater membrane strength in drought-resistant clones than in drought-sensitive clones. In the second experiment, three drought-resistant and three drought-sensitive poplar clones (including P. trichocarpa) were grown at two levels of N and three levels of potassium (K) and either well-watered, cyclically droughted, or droughted once. Cavitation, osmotic potential, gas exchange, and nutrient mobilization were measured at each stage of drought and re watering, and fall nutrient retranslocation was monitored. Cavitation was greater with adequate foliar N than at deficiency levels. Moderate supplies of K increased cavitation, but luxury levels sometimes reduced cavitation by decreasing foliar water loss and thus xylem tension. Preconditioning did not reduce vulnerability to cavitation, but there was some evidence of cavitation reversal in a drought resistant clone at high N supply. Vessel diameters were 36.6 μm at low N but 45.2 μm at high N, so within Populus, larger diameter vessels correlated with susceptibility to cavitation. High N supply increased water stress during the first drought, but also increased instantaneous water use efficiency (WUE) before drought occurred, and osmotic adjustment and hardening after drought. Increased K also increased WUE before drought and decreased water stress (decreasing transpiration and wilting) at luxury levels, but did not influence osmotic adjustment or hardening. Mobilization of nutrients differed with speed and intensity of drought. Gradual drought led to resorption of N and P. In the second experiment, drought was too rapid for retranslocation. Nutrients became more concentrated; some (e.g., N) facilitated hardening and osmotic adjustment, and some (e.g., K) moved out of the leaves on re watering. In fall, N, P, Cu and K were resorbed, the latter more proficiently with greater N supply at low levels of K. Clones which were more productive on dry sites resisted severe, but not moderate cavitation. Cavitation-resistant clones maintained high transpiration rates (and less negative water potentials) in drought, especially after hardening, had more, but smaller, stomata and decreased leaf loss in drought, but did not have increased WUE or osmotic adjustment. Nitrogen fertilization increased cavitation, greater P supply reduced this effect, and K fertilization may make vessels more vulnerable to cavitation but decrease the tension on the xylem that causes cavitation. Nitrogen fertilization levels should be tailored to site water supplies, and appropriate P, and possibly K additions may increase drought resistance.
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