Via de sinalização mTOR no carcinoma urotelial da bexiga

Trabalho de Projeto apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Análises Laboratoriais Especializadas, área de especialização em Análise Biomédica

Cytocidal amino acid starvation of Saccharomyces cerevisiae and Candida albicans acetolactate synthase (ilv2{Delta}) mutants is influenced by the carbon source and rapamycin.

The isoleucine and valine biosynthetic enzyme acetolactate synthase (Ilv2p) is an attractive antifungal drug target, since the isoleucine and valine biosynthetic pathway is not present in mammals, Saccharomyces cerevisiae ilv2Delta mutants do not survive in vivo, Cryptococcus neoformans ilv2 mutants are avirulent, and both S. cerevisiae and Cr. neoformans ilv2 mutants die upon isoleucine and valine starvation. To further explore the potential of Ilv2p as an antifungal drug target, we disrupted Candida albicans ILV2, and demonstrated that Ca. albicans ilv2Delta mutants were significantly attenuated in virulence, and were also profoundly starvation-cidal, with a greater than 100-fold reduction in viability after only 4 h of isoleucine and valine starvation. As fungicidal starvation would be advantageous for drug design, we explored the basis of the starvation-cidal phenotype in both S. cerevisiae and Ca. albicans ilv2Delta mutants. Since the mutation of ILV1, required for the first step of isoleucine biosynthesis, did not suppress the ilv2Delta starvation-cidal defects in either species, the cidal phenotype was not due to alpha-ketobutyrate accumulation. We found that starvation for isoleucine alone was more deleterious in Ca. albicans than in S. cerevisiae, and starvation for valine was more deleterious than for isoleucine in both species. Interestingly, while the target of rapamycin (TOR) pathway inhibitor rapamycin further reduced S. cerevisiae ilv2Delta starvation viability, it increased Ca. albicans ilv1Delta and ilv2Delta viability. Furthermore, the recovery from starvation was dependent on the carbon source present during recovery for S. cerevisiae ilv2Delta mutants, reminiscent of isoleucine and valine starvation inducing a viable but non-culturable-like state in this species, while Ca. albicans ilv1Delta and ilv2 Delta viability was influenced by the carbon source present during starvation, supporting a role for glucose wasting in the Ca. albicans cidal phenotype.

MYC activity mitigates response to rapamycin in prostate cancer through eukaryotic initiation factor 4E-binding protein 1-mediated inhibition of autophagy.

Loss of PTEN and activation of phosphoinositide 3-kinase are commonly observed in advanced prostate cancer. Inhibition of mammalian target of rapamycin (mTOR), a downstream target of phosphoinositide 3-kinase signaling, results in cell cycle arrest and apoptosis in multiple in vitro and in vivo models of prostate cancer. However, single-agent use of mTOR inhibition has limited clinical success, and the identification of molecular events mitigating tumor response to mTOR inhibition remains a critical question. Here, using genetically engineered human prostate epithelial cells (PrEC), we show that MYC, a frequent target of genetic gain in prostate cancers, abrogates sensitivity to rapamycin by decreasing rapamycin-induced cytostasis and autophagy. Analysis of MYC and the mTOR pathway in human prostate tumors and PrEC showed selective increased expression of eukaryotic initiation factor 4E-binding protein 1 (4EBP1) with gain in MYC copy number or forced MYC expression, respectively. We have also found that MYC binds to regulatory regions of the 4EBP1 gene. Suppression of 4EBP1 expression resulted in resensitization of MYC-expressing PrEC to rapamycin and increased autophagy. Taken together, our findings suggest that MYC expression abrogates sensitivity to rapamycin through increased expression of 4EBP1 and reduced autophagy.

Cutting edge: distinct glycolytic and lipid oxidative metabolic programs are essential for effector and regulatory CD4+ T cell subsets.

Stimulated CD4(+) T lymphocytes can differentiate into effector T cell (Teff) or inducible regulatory T cell (Treg) subsets with specific immunological roles. We show that Teff and Treg require distinct metabolic programs to support these functions. Th1, Th2, and Th17 cells expressed high surface levels of the glucose transporter Glut1 and were highly glycolytic. Treg, in contrast, expressed low levels of Glut1 and had high lipid oxidation rates. Consistent with glycolysis and lipid oxidation promoting Teff and Treg, respectively, Teff were selectively increased in Glut1 transgenic mice and reliant on glucose metabolism, whereas Treg had activated AMP-activated protein kinase and were dependent on lipid oxidation. Importantly, AMP-activated protein kinase stimulation was sufficient to decrease Glut1 and increase Treg generation in an asthma model. These data demonstrate that CD4(+) T cell subsets require distinct metabolic programs that can be manipulated in vivo to control Treg and Teff development in inflammatory diseases.

Inter-annual variability of precipitation constrains the production response of boreal Pinus sylvestris to nitrogen fertilization

© 2015 Published by Elsevier B.V.Tree growth resources and the efficiency of resource-use for biomass production determine the productivity of forest ecosystems. In nutrient-limited forests, nitrogen (N)-fertilization increases foliage [N], which may increase photosynthetic rates, leaf area index (L), and thus light interception (IC). The product of such changes is a higher gross primary production and higher net primary production (NPP). However, fertilization may also alter carbohydrate partitioning from below- to aboveground, increasing aboveground NPP (ANPP). We analyzed effects of long-term N-fertilization on NPP, and that of long-term carbon storing organs (NPPS) in a Pinus sylvestris forest on sandy soil, a wide-ranging forest type in the boreal region. We based our analyses on a combination of destructive harvesting, consecutive mensuration, and optical measurements of canopy openness. After eight-year fertilization with a total of 70gNm^-2, ANPP was 27±7% higher in the fertilized (F) relative to the reference (R) stand, but although L increased relative to its pre-fertilization values, IC was not greater than in R. On the seventh year after the treatment initiation, the increase of ANPP was matched by the decrease of belowground NPP (78 vs. 92gCm^-2yr^-1; ~17% of NPP) and, given the similarity of IC, suggests that the main effect of N-fertilization was changed carbon partitioning rather than increased canopy photosynthesis. Annual NPPS increased linearly with growing season temperature (T) in both treatments, with an upward shift of 70.2gCm^-2yr^-1 by fertilization, which also caused greater amount of unexplained variation (r²=0.53 in R, 0.21 in F). Residuals of the NPPS-T relationship of F were related to growing season precipitation (P, r²=0.48), indicating that T constrains productivity at this site regardless of fertility, while P is important in determining productivity where N-limitation is alleviated. We estimated that, in a growing season average T (11.5±1.0°C; 33-year-mean), NPPS response to N-fertilization will be nullified with P 31mm less than the mean (325±85mm), and would double with P 109mm greater than the mean. These results suggest that inter-annual variation in climate, particularly in P, may help explaining the reported large variability in growth responses to fertilization of pine stands on sandy soils. Furthermore, forest management of long-rotation systems, such as those of boreal and northern temperate forests, must consider the efficiency of fertilization in terms of wood production in the context of changes in climate predicted for the region.

Big or fast: two strategies in the developmental control of body size.

Adult body size is controlled by the mechanisms that stop growth when a species-characteristic size has been reached. The mechanisms by which size is sensed and by which this information is transduced to the growth regulating system are beginning to be understood in a few species of insects. Two rather different strategies for control have been discovered; one favors large body size and the other favors rapid development.

Structural Capital of University Spin-Out Firms: The Moderating Role of University Incubators

University incubators (UI) are generally believed to be important in the successful commercialisation of university spin-outs (USO) with over half of all UK Universities having established an on-campus UI. In this chapter we examine the value of UIs in the spin-out process, focusing on the structural networks of USOs located in a UI as compared to USOs in a University with no access to a UI. Our primary research question is therefore: to what extent does the structural network of USOs with access to an on-campus UI differ from USOs without? The research therefore con-tributes to a growing critique of the effectiveness of UIs in commercialis-ing academic research and the recognition of positive direct and indirect externalities from participation in networks. Through network mapping of all USOs from two research intensive universities, we profile and ana-lyse the formal and informal network ties of USOs to various partners in-ternal and external to the host university. Through interviews we also consider how these networks enhance the resources and capabilities of USOs. Our findings highlight significant differences, with USOs located in a UI having more informal but fewer formal ties, both to other USOs as well as within the host University. In contrast, location in an incuba-tor was not found to affect the extent and nature of ties with external or-ganisations. Reasons for these differences are examined through inter-views with the USOs and point to various factors including the proactive brokering role of incubator and university staff, university bureaucracy, the hidden networks of executive board members across USOs, university equity investment policy and complementary technologies.

STC-1 Cells

Gastrointestinal hormones such as cholecystokinin (CCK), glucagon like peptide 1 (GLP-1), and peptide YY (PYY) play an important role in suppressing hunger and controlling food intake. These satiety hormones are secreted from enteroendocrine cells present throughout the intestinal tract. The intestinal secretin tumor cell line (STC-1) possesses many features of native intestinal enteroendocrine cells. As such, STC-1 cells are routinely used in screening platforms to identify foods or compounds that modulate secretion of gastrointestinal hormones in vitro. This chapter describes this intestinal cell model focussing on it’s applications, advantages and limitations. A general protocol is provided for challenging STC-1 cells with test compounds.

Estudo de otimização de imagem e dose em mamografia digital

O objetivo deste trabalho foi efetuar um estudo de otimização dos parâmetros de exposição do mamógrafo digital da marca GE, modelo Senographe DS instalado no Instituto Português de Oncologia de Coimbra (IPOC) baseado numa análise contraste detalhe e avaliar o impacto do resultado obtido na melhoria da capacidade de detecção clínica das estruturas da mama. O mamógrafo em estudo dispõe de um sistema de controle automático da exposição designado por sistema AOP (Automatic Optimization of Parameters) que foi otimizado pelo fabricante a partir da razão contraste ruído. O sistema AOP é usado na prática clínica na quase totalidade dos exames de mamografia realizados no IPOC. Tendo em conta o tipo de estrutura que se pretende visualizar na mamografia, nomeadamente estruturas de baixo contraste como as massas e estruturas de dimensão submilimétrica como as microcalcificações, a análise contraste detalhe poderia constituir uma abordagem mais adequada para o estudo de otimização dos parâmetros de exposição uma vez que permitiria uma avaliação conjunta do contraste, da resolução espacial e do ruído da imagem. Numa primeira fase do trabalho foi efetuada a caracterização da prática clínica realizada no mamógrafo em estudo em termos de espessura de mama comprimida “típica”, dos parâmetros técnicos de exposição e das opções de processamento das imagens aplicadas pelo sistema AOP (combinação alvo/filtro, tensão aplicada na ampola - kVp e produto corrente-tempo da ampola - mAs). Numa segunda fase foi realizado um estudo de otimização da qualidade da imagem versus dose na perspectiva dos parâmetros físicos. Para tal foi efetuada uma análise contrastedetalhe no objeto simulador de mama CDMAM e usada uma figura de mérito definida a partir do IQFinv (inverted image quality figure) e da dose glandular média. Os resultados apontaram para uma diferença entre o ponto ótimo resultante do estudo de otimização e o ponto associado aos parâmetros de exposição escolhidos pelo sistema AOP, designadamente no caso da mama pequena. Sendo a qualidade da imagem na perspectiva clínica um conceito mais complexo cujo resultado da apreciação de uma imagem de boa qualidade deve ter em conta as diferenças entre observadores, foi efetuado na última parte deste trabalho um estudo do impacto clínico da proposta de otimização da qualidade de imagem. A partir das imagens realizadas com o objeto simulador antropomórfico TOR MAM simulando uma mama pequena, seis médicos(as) radiologistas com mais de 5 anos de experiência em mamografia avaliaram as imagens “otimizadas” obtidas utilizando-se os parâmetros técnicos de exposição resultantes do estudo de otimização e a imagem resultante da escolha do sistema AOP. A análise estatística das avaliações feitas pelos médicos indica que a imagem “otimizada” da mama pequena apresenta uma melhor visualização das microcalcificações sem perda da qualidade da imagem na deteção de fibras e de massas em comparação com a imagem “standard”. Este trabalho permitiu introduzir uma nova definição da figura de mérito para o estudo de otimização da qualidade da imagem versus dose em mamografia. Permitiu também estabelecer uma metodologia consistente que pode facilmente ser aplicada a qualquer outro mamógrafo, contribuindo para a área da otimização em mamografia digital que é uma das áreas mais relevantes no que toca à proteção radiológica do paciente.

Metodologia de apoio à gestão energética de edifícios e iluminação pública dos municípios: caso de estudo: "Município de Albufeira"

Dissertação de mest., Engenharia do Ambiente (Avaliação e Gestão Ambiental), Faculdade de Ciências e Tecnologia, Univ. do Algarve, 2010

Estudo do processo de reorientacão do campo do director por acção de um campo magnético numa fase nemática confinada

Estudamos teoricamente as transi ções de Fr éedericksz nas geometrias interm édias entre: (i) afunilamento e tor ção (ii) tor ção e flexão; e (iii) fexão e afunilamento. Foram determinadas as condi ções em que a transi ção entre o estado não deformado e o estado homogeneamente deformado (transi ção de Fr éedericksz usual) e substituída pela transi ção entre o estado não deformado e o estado deformado com estrutura peri ódica. Tamb ém estudamos te órica e experimentalmente a dinâmica de reorienta ção do campo do director ap os rota ção s ubita da amostra num campo magn ético uniforme. Consideramos monodomí nios de cristais l íquidos nem áticos uniaxiais não quirais diamagnéticos de baixo peso molecular, contidos entre duas fronteiras planas uniformes paralelas e r ígidas com alinhamento planar. Simulamos e reproduzimos, na geometria de tor ção toda a evolu ção do campo do director desde o momento em que se impõe uma rota ção s úbita e at é ao instante em que se observa a forma ção de bandas.

Mammalian Target of Rapamycin Complex 2 Controls CD8 T Cell Memory Differentiation in a Foxo1-Dependent Manner.

Upon infection, antigen-specific naive CD8 T cells are activated and differentiate into short-lived effector cells (SLECs) and memory precursor cells (MPECs). The underlying signaling pathways remain largely unresolved. We show that Rictor, the core component of mammalian target of rapamycin complex 2 (mTORC2), regulates SLEC and MPEC commitment. Rictor deficiency favors memory formation and increases IL-2 secretion capacity without dampening effector functions. Moreover, mTORC2-deficient memory T cells mount more potent recall responses. Enhanced memory formation in the absence of mTORC2 was associated with Eomes and Tcf-1 upregulation, repression of T-bet, enhanced mitochondrial spare respiratory capacity, and fatty acid oxidation. This transcriptional and metabolic reprogramming is mainly driven by nuclear stabilization of Foxo1. Silencing of Foxo1 reversed the increased MPEC differentiation and IL-2 production and led to an impaired recall response of Rictor KO memory T cells. Therefore, mTORC2 is a critical regulator of CD8 T cell differentiation and may be an important target for immunotherapy interventions.

Recueil de lettres et de pièces originales, et de copies de pièces indiquées comme telles dans le dépouillement qui suit.

Contient : 1 Lettre de « MARIE,... royne de Hongrye... au roy » ; 2 Lettre de « MARGUERITE,... royne de Navarre... à monseigneur de Villandry, secretaire des finances du roy... septembre » ; 3 Lettre de « FRANÇOYS [Ier]... A l'abbaie de Long Pont, le deuxiesme jour de may mil V.C.XXXIIII » ; 4 Lettre de « CLAUDE DE LORRAINE,... au roy... De Joimville, le XIIIIe jour de febvrier » ; 5 Lettre de « FRANÇOYS [DE BOURBON, comte] DE ST POL,... à monseigneur le grant maistre... Au camp de Loca, le Ve de septembre... V.C.XXVIII » ; 6 « Roolle des dons, voyages, recompences et menuz plaisirs de monseigneur le duc d'Orleans. Du mois de juillet l'an mil cinq cens quarente quatre » ; 7 Lettre, en italien, de « el cardinale TRIVULTIO,... al re... Di Roma, X agosto M.D.XXXIIII » ; 8 Lettre de « FRANÇOYS [DE BOURBON, comte]... DE SAINT POL », à « monseigneur de Barbezieulx,... A Vallence, ce dimenche matin XVIIIe d'octobre » ; 9 Lettre de « LOYS, cardinal DE BOURBON,... à monseigneur de Villandry,... A Paris, se XVIIIe decembre » ; 10 Lettre de « MARAVELIA,... au roy... De Lyon, le IXme jour de novembre » ; 11 Lettre de « POMPONIO TRIVULTIO,... au roy... A Lyon, le IIIIme jour d'apvril mil V.C.XXIX » ; 12 Lettre de « POMPONIO TRIVULTIO,... au roy... A Lyon, le XXIXme jour d'octobre mil V.C.XXVIII » ; 13 « Copie » de « lettres de NICOLAS RAINCE,... à monseigneur de Lautrec,... De Viterbe, ce mardi XXIIIe jour de juin mil V.C.XXVIII » ; 14 Lettre du « president des comptes de Provence, JOACHIN,... à monseigneur... le grant maistre... De Viterbe, ce XXIIIIe jour d'aoust M.V.C.XXVIII » ; 15 Lettre de « DE BAYF,... à monseigneur... de Villandry,... De Venize, ce XXXe jour d'octobre... 1532 » ; 16 Lettre de « BREZE,... au roy... A Rouen, le XXme jour d'octobre » ; 17 Lettre de « POMPONIO TRIVULTIO,... au roy... A Lyon, le XIIIIme jour de may » ; 18 Lettre de « GALEAS VISCONTE,... au roy... De Chambery, ce XXVIe de may » ; 19 Lettre du roi FRANÇOIS Ier « à la royne de Honguerye, par monseigneur Helyn. De Chantilly, le XXVIe jour de novembre 1538 ». Double ; 20 Copie d'une lettre du roi FRANÇOIS Ier à « monseigneur de Vaulx » ; 21 Lettre, en italien, de « GALEATIO VESCONTE,... al re... In Alexandria, a lo penultimo de mazo » ; 22 Lettre de « POMPONIO TRIVULTIO,... au roy... A Lyon, le Xme jour d'aoust... 1528 » ; 23 Lettre, en italien, de « GALEATIO VESCONTE,... al... re... De Lyone, alli XXX di maggio » ; 24 Lettre, en italien, de « GALEAZ VESCONTE » à « Angelo Bolano,... Da Alexandria, a li XII de ottobre 1528 » ; 25 « Lettre de monseigneur l'evesque d'Ast à N. Raince,... Dal Campo, alli XXVII di jugno M.V.C.XXVIII ». En italien. Copie ; 26 Lettre de « messieurs DE GRIGNAN et » du « juge mage de Nismes... au roy... De Suze, ce Xme d'octobre ». En italien ; 27 Mémoire, en italien, à Louise de Savoie, sur l'armée française en Lombardie. « Della Tor du Pin, XII februarii » ; 28 Lettre de « POMPONIO TRIVULTIO,... au roy... A Lyon, le Xme jour d'aoust » ; 29 Lettre, avec chiffre, de ROBERT CENALIS, « evesque d'Avranches... au roy... A Venyse, le XIIIe d'octobre » ; 30 Lettre de « NICOLAS RAINCE,... au roy... De Rome, ce mardi XIIIe jour de juillet M.V.C.XXXV » ; 31 Lettre de GEORGES « DE SELVE, evesque de Lavaur... au roy... A Venise, ce cinquiesme de juillet mil cinq cent XXXVI » ; 32 Lettre de « JACQUES DE ROHAN,... au roy... A Yheric, ce dixme de juign » ; 33 Lettre de « P[IERRE FILLEUL], arcevesque d'Aix... à monseigneur... de Bury,... A Paris, le XXVIIIe jour d'aoust » ; 34 Lettre de « MYCHEL DE LUPPE,... au roy... A Troyes en Champaigne, le XVIe jour de juing » ; 35 Lettre du « baron DE MONTMOREAU,... au roy... A Troyes en Champaigne, le XVIe jour de juing » ; 36 Lettre de « ROBERT GEDOYN » à « monseigneur d'Alluye,... A Calays, le derrenier jour de septembre » ; 37 Lettre de « DE PONTHIER » à « monseigneur [d'A]lluye,... A Paris, le XXVIIIme d'aoust » ; 38 Lettre de « LA FAYETE,... au roy... A Boullongne, ce XXe jour de septembre » ; 39 Lettre de « LA FAYETE,... au roy... A Boullongne, ce XVIe jour de septembre » ; 40 Placet au roi concernant « les terres... de Gournay et Gaillefontennes... et... le duché de Longueville ». Copie ; 41 Lettre de « JAQUES OLIVIER,... à... monseigneur d'Alluye,... A Paris, le XXIIIe jour d'aoust » ; 42 Lettre de « LA FAYETE,... au roy... A Boullongne, ce lundy XVIIe jour de juuing » ; 43 Lettre de « JAQUES OLIVIER,... à monseigneur... d'Alluye,... A Paris, le XXVIme juillet » ; 44 Lettre de « JEHAN MARTELLI » à « monseigneur de [C]ourcelles,... De Rome, ce IIe jour de decembre » ; 45 Lettre de « JAQUES OLIVIER,... à monseigneur... d'Alluye,... A Paris, ce dernier jour d'aoust » ; 46 Lettre des « gens des comptes en Bretaigne », signée : « Burillon,... à monseigneur... d'Aluye,... A Nantes, en la chambre des comptes, le tiers jour de decembre » ; 47 Lettre des habitants « de Tournay » au roi. « A Tournay, ce XXIIe jour de septembre » ; 48 Fragment d'un traité d'alliance offensive et défensive entre le « roy tres chrestien » et ses « alliez » ; 49 Lettre de « THOMAS BOHIER » au trésorier Robertet. « A Mylan, ce mercredi XIe jour d'avril » ; 50 Copic de lettre avertissant le roi François Ier que « les differens qui estoient entre l'Empereur et » lui « ont esté vuydez, appoinctez et paciffiez » ; 51 Lettre, en latin, de LOUIS DE BOURBON, « laudunensis cardinalis », au roi François Ier. « Rome, ex palatio apostolico, die XX martii M.D.XXI » ; 52 Lettre du baron de « SAINT BLANCARD » à la reine. « A Marseille, ce penultime jour de may » ; 53 Lettre de « JAQUES DE MUILLY » au roy. « Devant Saulce, ce IIIe jour d'octobre » ; 54 Lettre de « CHARLES [HEMART-DENONVILLE], evesque de Mascon... à monseigneur... de Villandry,... De Rome, le Vme jour de febvreier 1535 » ; 55 Lettre de « POMPONIO TRIVULTIO,... au roy... A Lyon, le XXIme jour de juillet 1528 » ; 56 Lettre, en italien, de « GIULIANO DE LA SPEZA,... al... principe de Orangio... In La Mirandola, a X de giugno 1528 ». Copie ; 57 Lettre de « NICOLAS RAINCE,... à monseigneur... de Villandry,... De Rome, ce mercredi XIe jour de may M.V.C.XXX » ; 58 Lettre de « NICOLAS RAINCE,... à monseigneur... de Villandry,... De Rome, ce mercredi XIe jour de may 1530 » ; 59 Inventaire des munitions de l'artillerie demandées par Lautrec en Italie ; 60 Lettre de « PIERRE [CASTELNAU DE] CLERMONT [LODEVE] à monseigneur de Vilandry,... De Bayonne, le IIIme de juing » ; 61 Lettre de « GUY DE LAVAL,... à monseigneur de Villeandry,... De Viterbe, ce XXIIIIe de may » ; 62 Lettre, en italien, de « BONAVENTURA PISTOPHILUS », secrétaire du duc de Ferrare ; 63 Mémoire adressé au roi par un ambassadeur de l'Empereur, concernant la délivrance des corsaires sujets de l'Empereur ; 64 Lettre de « l'abbé de Chesau Benoist,... au roy... De Chesau Benoist » ; 65 Lettre de « DE GRIGNAN,... à monseigneur... de Vilandry,... De Romme, ce XXIIIe jour de novembre 1588 » ; 66 Lettre, en italien, d'« il vescovo di Lodi... a... monsignore... di Villandry,... Di Venetia a Murano, a di XIX di settembre M.D.XXX » ; 67 Lettre de « NICOLAS DE BOUSSUT, [Sr DE] LONGUEVAL, au roy... Au camp, à Anconne, le XXVIIIe janvier » ; 68 Lettre de « GLAUDE DURRE,... au roy... D'Aix, ce XXVIe d'aoust » ; 69 Lettre de « POMPONIO TRIVULTIO,... au roy... A Lyon, le VIIIme jour de septembre... V.C.XXVIII » ; 70 Lettre de « LAMBERT MEIGRET,... à monseigneur... le legat... De Salleurre, le IIme jour de novembre » ; 71 Lettre de « NICOLAS RAINCE,... à monseigneur... de Villandry,... De Bolongne, ce lundi soir XXVIIIe jour de novembre 1530 » ; 72 « Copie des lettres mandées par la court de parlement de Grenoble à monseigneur de Savoye,... A Grenoble, le XVIe de janvier mil cinq centz trente quatre » ; 73 Minute d'une lettre de FRANÇOIS Ier à « monseigneur du Puy Sainct Martin,... A Angolesme, juillet mil V.C.XXX » ; 74 Lettre de « GALEAS VISCONTE,... au roy... A Lion, ce XXVIe de fevrier » ; 75 Lettre du « cappitaine LA CLAYETE,... à monseigneur... le trésorier Robertet,... A Bayonne, le XXe jour d'aoust »

The use of diatom assemblages to determine paleotrophic changes in lakes

The purpose of this study was to develop a classifi cation scheme for l ake trophic status based on the relative abundance of l ake sediment diatom trophic indicator species. A total of 600 diatom frustules were counted from the surface sediments of e a ch of 30 lakes selected to repr e seni~ a continuum from u.lt ra-oligotrophic t,o fairly eutrophic but not hype r-' eutrophic conditions. Published autecological information was used to determine the trophic indicator status of each of the s pecies. A quotieht was derived by dividing the s um of all the e utrophic indicator species by the sum of all oligotrophic indicai.-:.or species. Oligo'- mesotrophic. mesotrophic and meso-eutrophic species were added to both the numerator and denomina tor. Five categories of diatom i.nferred trophic status were recognized : ultra-oligotrophic - 0'-0.2:3, oligotrophic::: 0.24-0 . 70, mesotrophic :: 0.'71 -0.99, meso-elxtrophic :: 1. 00-1. '78 and eutrophic:: 1.. 79-2. 43. But only three of these (oligotrophic:: 0-0.69, mesotrophic ::: 0 . 70'-1.69 j and eutrophic:: 1.70-2.50) proved usef ul. The present study of the relationship between diatom inferred trophic status and the literature-derived trophic status of SO lake s (which were purposely chosen to represent a broad spectrum of lakes in Canada) indicated that: 1) Based on diatom species (assemblages ) it is possible to segregate the lakes from which. th",)se diatoms were taken into three basic categories : o ligotrophic, mesotrophic and eutrophic lake types. ~~) It was not possible t,o separate meso-eutrophic and o l igo-mesotrophic lakes f rom mesotrophic l akes as the the degree of overlap betwee n the diat,om species in these lake types was extremely high. 3) Ha d mo r e ul tra-oligotroph,ic lakes been sampled it might have been possible to more a ccurately s eparate them f rom oligotrophic Jakes. 4 ) Had. more humic lakes been sampled in this s tudy I f eel it would have been possible to identify a unique diatom a ssemblage which would h a ve chara cterized t his lake type . Re gression analyses were performed using the aforementioned diatom inferred trophic index as a f unction of 1) log Sec chi transparency (r = - 0.70) 2) total phosphorus (r = 0. 77 ) and 3) chlorophyll-a (r = 0.74). Once e ach of these rel ationships had been established , it was possible to infer paleotrophic (downcore) changes in an oligotrophic lake (Barbara Lake) and in a eutrophic lake (Chemung Lake) . Barbara Llake was dominated by oligotrophic s pecies and remained oligotrophic throughout the 200-·year history r epresented by i t s 32 em long sediment core. Chemung Lake is currently dominated. by eutrophic species but went through a mesotrophic st,age which was associated with a rise in the water level of the lake followi n g dam construction in its watershed in the early 1.900 J ::;. This was followed by its reversion to it,s present day eutrophic stage (dominated by eutrophic species) possibly as a r esult of shallowing process which can be attributed to " silting' up" of the reservoir and the invasion of the l ake by Myriophyllum spjcatum (Eurasian milfoil) i n the 1970's . In addition, nutrient .:r':l.ch run"'offwhich resulted from increased human a.ctivities associated with cottage development along its shores has contribut ed to its eutrophication. There is some evidence that the rat,e o :f its prog ressive eutrophication has declined during the last decade. This was correlated with legislation enacted in the 60's and 70's in Ontario which was aimed at reducing nutrient loading from cottages.

Crystal growth, characterization and point contact spectroscopy on CuxTiSe₂

Various s e t s of single c rys t a l s and poly c rys t a l s of Cux TiSe2 were grown. X- r ay diffraction and ene rgy dispersive spe c t ros copy r e sul t s verified tha t the c rys t a l s were the cor r e c t compos i t ion and c rys t a l s t ruc tur e . Re s i s t ivi ty me a sur ement s and magne t i c sus c ept ibi l i ty me a sur ement s de t e rmined the supe r conduc t ing t r ans i t ion t empe r a tur e s for the c rys t a l s . The c rys t a l s in each growth had various supe r conduc t ing t r ans i t ion t empe r a tur e s . Also, the me a sur ement s indi c a t ed tha t the c rys t a l s were inhomogeneous. Point cont a c t spe c t ros copy expe r iment s were employed on various single c rys t a l s . Inspe c t ion of the da t a indi c a t ed tha t the ma t e r i a l ha s a single ene rgy gap . A progr am was bui l t ut i l i z ing the Levenbe rg-Ma rqua rdt me thod and theory on point cont a c t spe c t ros copy to de t e rmine the supe r conduc t ing ene rgy gap. Plot s of the supe r conduc t ing ene rgy gap a t various t empe r a tur e s were in di s agr e ement wi th wha t was expe c t ed for a convent iona l supe r conduc tor .