Desmonte de Maciços Rochosos: optimização da perfuração

Este trabalho pretende avaliar e melhorar o modo de execução da aplicação da técnica de perfuração, não comprometendo a jusante, no ciclo de operações, a qualidade do desmonte, visando assim, uma optimização técnico-económica. Este manuscrito irá centrar-se na optimização da etapa da perfuração, visando assim a optimização do ciclo total da perfuração. As tarefas realizadas numa pedreira constituem um ciclo de operações. Uma das operações envolvidas no desmonte de maciços rochosos é a perfuração. A forma como esta é executada é determinante para o sucesso do desmonte. O correcto dimensionamento dos acessórios de perfuração, afiação de bits, manutenção preventiva dos equipamentos de perfuração e a constante formação dos operadores fazem parte de um conjunto de acções que irão determinar o sucesso da operação de perfuração, tendo sempre em vista, uma optimização técnico-económica, ou seja, produzir mais a um custo mais baixo. O estudo dos parâmetros do maciço rochoso aliado a uma perfuração cuidadosa e alinhada é evidenciado com o intuito de uma abordagem de geoengenharia integrada dos maciços rochosos. O estudo foi realizado na pedreira da APS, S.A. (Pedreira de Monte Chãos), tendo como análise os dados desde o início do projecto até à data. Para fundamentar este estudo, aborda-se os parâmetros geológico-geotécnicos e geomecânicos do maciço remanescente, verificando assim as ferramentas de corte mais adequadas ao caso e averiguar a influência da afiação de bits, quer seja manual ou semiautomática, e de que forma a mesma irá influenciar nos rendimentos e vidas úteis obtidas, tendo como objectivo, melhorar o custo por metro de furação realizado.

Cartografia de zonamento geotécnico em frentes de escavação de maciços rochosos heterogéneos (túnel do Marão): aplicação da classificação geomecânica GSI|2013

Este estudo pretende discutir a validade da aplicação da mais recente versão do “GSI – Geological Strength Index” (Hoek et al., 2013) em maciços rochosos heterogéneos por aplicação num projecto de obra subterrânea em execução. O estudo envolveu a caracterização geológicageotécnica nas duas frentes de escavação da frente “Poente” da empreitada de construção do Túnel do Marão (N de Portugal) tendo sido cartografados 305 metros no conjunto das duas frentes em 74 avanços consecutivos. Para esta caracterização foram coligidos e uniformizados dados geológicos, geotécnicos e geomecânicos relativos aos levantamentos realizados a cada avanço. A técnica da amostragem linear foi aplicada para a cartografia das descontinuidades que permitiu estabelecer o grau de compartimentação do maciço rochoso. Além disso, procedeu‐se a um tratamento estatístico das descontinuidades, bem como dos parâmetros geológico‐geotécnicos e geomecânicos associados. Os zonamentos geotécnicos e geomecânicos das secções em análise foram realizados sempre em estreita ligação com o conhecimento das características do maciço in situ. Procurou‐se estabelecer termos de comparação entre a versão do GSI|2013 e as versões anteriores (GSI|98, GSI|2001) por aplicação para os avanços cartografados. Pretende‐se que este trabalho contribua para um maior conhecimento da mais recente versão do “Geological Strength Index” (2013) para a sua aplicabilidade em projectos de geoengenharia.

Taludes rochosos. Metodologias de inspecção e de avalialição de segurança. Caso de estudo das vertentes rochosas de S. Simão

A instabilização de taludes rochosos, com consequências mais ou menos gravosas, repete-se com frequência no território nacional. Os enquadramentos destes incidentes são diversos, sendo mais comum e mais visível a sua ocorrência em taludes adjacentes a vias de comunicação. No entanto, o fenómeno repete-se também em vertentes naturais, geralmente em alturas de pluviosidade mais prolongada e intensa. No presente trabalho reveem-se conceitos associados a maciços rochosos, nomeadamente as principais classificações geotécnicas e as diferentes tipologias de instabilidade em taludes rochosos. Desenvolve-se um caso de estudo de uma vertente localizada em S. Simão, concelho de Amarante. Percorrem-se as sucessivas fases de estudo, incluindo a realização da fotografia aérea com recurso a um veículo não tripulado, a geração de um modelo 3D de elevada precisão da vertente e a caracterização e a classificação dos diferentes afloramentos rochosos. Desenvolve-se uma metodologia de inspeção com a criação de dois conjuntos de fichas e propõe-se o agravamento da classificação das anomalias perante a simultaneidade de ocorrência de anomalias de idêntica gravidade e a hierarquização dos blocos potencialmente instáveis, de acordo com os respetivos níveis de gravidade (NGB). Recorre-se ao programa de modelação da queda de blocos, “Rocfall (4.0”, da “Rocscience”, a partir de trajetórias definidas no modelo 3D gerado e propõem-se soluções de reforço e de proteção da vertente.

Estudo sobre viabilidade de produção descentralizada de energia à custa do efeito chaminé

A procura por alternativas ao atual paradigma energético, que se caracteriza por uma predominância indiscutível das fontes combustíveis fósseis, é o motivo primário desta investigação. A energia emitida pelo Sol que chega à Terra diariamente ultrapassa em várias ordens de grandeza a energia que a nossa sociedade atual necessita. O efeito chaminé é uma das formas de aproveitar essa energia. Este efeito tem origem no diferencial de temperaturas existente entre o interior e o exterior de uma chaminé, que provoca um gradiente nas massas volúmicas do fluido entre o interior e o exterior da chaminé, induzindo assim um fluxo de ar. Esta diferença de temperaturas radica na exposição da face exterior da chaminé à radiação solar. No sistema que nos propomos estudar, o ar entra na chaminé por pequenos orifícios situados na sua base, e, ao tomar contacto com as paredes internas da chaminé, aquece desde a temperatura ambiente, Ta, até à temperatura interna, Ti . Este aumento de temperatura torna o ar dentro da chaminé mais “leve” em comparação com o ar mais frio do exterior levando-o a ascender ao longo do interior da chaminé. Este escoamento contém energia cinética que pode, por exemplo, ser transformada em energia elétrica por intermédio de turbinas. A eficiência de conversão da energia será tanto maior quanto menor for a velocidade do ar a jusante da turbina. Esta tecnologia poderá ser instalada de forma descentralizada, como acontece com as atuais centrais concentradoras solares térmicas e fotovoltaicas localizadas na periferia de grandes cidades ou, alternativamente, poderá ser inserida no próprio tecido urbanístico. A investigação demonstra que as dimensões da chaminé, a irradiação e a temperatura do ar são os fatores com maior impacto na potência hidráulica gerada.

The Shading Sign: Is It Exclusive of Endometriomas?

OBJECTIVES: To investigate if the shading sign is an exclusive MRI feature of endometriomas or endometrioid tumors, and to analyze its different patterns. METHODS: Three hundred and fourty six women with adnexal masses who underwent 1.5/3-T MRI were included in this retrospective, board-approved study. The shading sign was found in 56 patients, but five cases were excluded due to lack of imaging follow-up or histological correlation. The final sample included 51 women. The type of tumor and the pattern of shading were recorded for each case. RESULTS: Thirty endometriomas and five endometrioid carcinomas were found. The remaining 16 cases corresponded to other benign and malignant tumors. The overall sensitivity, specificity, positive predictive value, and negative predictive value were 73%, 93%, 59%, and 96%, respectively. Restricting the analysis to cystic lesions without solid or fat component, sensitivity, specificity, positive predictive value, and negative predictive value were 73%, 96%, 94%, and 80%. Five shading patterns were identified: layering (15.7%), liquid-liquid level (11.8%), homogenous (45.1%), heterogeneous (11.8%), and focal/multifocal shading within a complex mass (19.6%). No significant correlation was found between these patterns and the type of tumor. CONCLUSIONS: The shading sign is not exclusive of endometriomas or endometrioid tumors. Homogenous shading was the most prevalent pattern in endometriomas and half of the cases with focal/multifocal shading within a complex mass were endometrioid carcinomas.

Conjunctival MALT lymphoma: utility of FDG PET/CT for diagnosis, staging, and evaluation of treatment response.

A 67-year-old woman was referred for staging of a mucosa-associated lymphoid tumor lymphoma involving the left conjunctiva. CT scan had shown paravertebral and pelvic masses, and a breast nodule. FDG PET/CT demonstrated moderately increased uptake in the left ocular conjunctiva and confirmed the paravertebral and pelvic masses and the breast nodule. Moreover, abnormal FDG uptake was shown in 2 breast nodules, the flank, the gluteus maximus, and the gastric cardia. The patient received 6 cycles of rituximab-bendamustine chemotherapy with a complete clinical and metabolic response at the 6-month follow-up PET/CT and remained relapse-free without visual acuity problem after a 36-month follow-up.

Biología y pesquería del perico o dorado Coryphaena hippurus, febrero 2010

La prospección para evaluar la biología y pesquería de Coryphaena hippurus perico o dorado, se efectuó del 10 de febrero al 1 de marzo 2010, a bordo del BIC Imarpe V. El área de extracción fue de 4°59’32,8’’ a 10°15’20,1’’S y de 79°55’16,2’’ a 84°35’04,2’’W; la captura total fue 1.500,5 kg. La CPUE varió de 0,9 a 18,2 kg/Nº Anzuelos/1000*hora efectiva de pesca. Se encontró alta selección interespecífi ca del espinel superfi cial, al capturar 87,8% de perico y 8 especies de peces, tortugas y cefalópodos. El rango de tallas para hembras fue 79 - 141 cm de LT, en machos fue 100 - 157 cm LT. El factor de condición de Fulton en machos varió de 0,30 a 0,46 y en hembras de 0,32 a 0,40. Se determinó para hembras: L∞=148,92 cm, tasa de crecimiento anual (K) 1,081, se estimó t0 = -0,076 años, el Índice de performance Ǿ= 4,38; para machos, estos parámetros fueron L∞=169,75 cm, tasa de crecimiento anual (K) de 0,893, t0 = -0,115, índice de performance Ǿ= 4,40. La curva de crecimiento en talla para hembras, indica que a un año de edad la LT es 102,4 cm y en machos 107 cm. El máximo crecimiento en peso para hembras y machos fue a 1,5 años de vida. El Índice gonadosomático (IGS) fl uctuó de 3,2 a 4,6 mostrando comportamiento heterogéneo. La proporción sexual fue de 2:1 favorable a las hembras. La fecundidad parcial fue de 324.416 ovocitos por tanda de desove. La fecundidad relativa fue 56 ovocitos/ gramo de peso corporal. El tipo de alimento fue peces, cefalópodos y crustáceos con dominancia de Exocoetus volitans (%IRI = 31,6), Argonauta spp. (%IRI = 26,4) mostrando variaciones según zonas y tallas. El consumo de alimento fue 472,7 g/ind./día correspondiente a 7,4% de su peso corporal, presentando fl uctuaciones con respecto a la talla; alimentándose en horas de la mañana, con un máximo entre las 8:00 y 9:59 horas. Se encontraron 5.762 parásitos, identifi cándose 8 especies en cuatro taxas. La prevalencia parasitaria indica que Tentacularia coryphaenae y Bathycotyle coryphaenae alcanzan el 100%, seguido por Hysterothylacium sp. 62% y Caligus coryphaenae 46%. El mayor número de parásitos se encontró en el estómago. Los peces entre 96–100 cm de LT son los más parasitados. La mayor incidencia parasitaria se encontró en la zona norte, en el tramo Paita-Salaverry. Los registros de temperatura en la columna de agua fueron de 12,7 a 27,3 °C y las ATSM de 0,2 a 4,1 °C. Por el frente oceánico se observaron comportamientos térmicos cálidos asociados a las masas de Aguas Ecuatoriales Superfi ciales y Aguas Subtropicales Superfi ciales y por la zona costera se localizaron Aguas Costeras Frías tanto en Chimbote como en Chicama con temperaturas próximas a 22,0 °C. La concentración de oxígeno disuelto superfi cial se presentó favorable para el perico.

A reconnaissance study of the metamorphic petrology and volcanic geochemistry of a portion of the Island Lake greenstone belt, Manitoba /

The Island Lake greenstone belt is one of the major Archean supracrustal exposures in the northwestern part of the Superior Province of the Canadian Shield. This belt is subdivided into two units: 1) a lower sequence characterised by pillowed to massive, locally pyroclastic, basalt to andesite with a thin central zone of felsic derivatives, all of which are interbedded with and overlain by thick sequences of turbidite facies rock; 2) the upper unit which consists of thick stratified conglomerate overlain by thickly bedded arkose and feldspathic greywacke. Reconnaissance sampling traverses were completed across both the strike of the belt and along its margins with adjacent granitoids. Most of the belt is within the greenschist metamorphic f acies with amphibolite facies occurring in certain areas near t he margins. A post-tectonic, low pressure thermal event may be responsible for the development of a unit of cordierite schi s t which stretches southeastwards from the east end of Cochrane Bay. Volcanism is cyclical in nature changing from tholeiitic to calc-alkaline. There is a general progression in the character of the lavas from mafic t o felsic with stratigraphic height. Chemica l d a ta sugges t that h i gh level fractionation of a mantle- derived ' dry' magma i s t he s ource of the thole i iti c lavas. Contamination of this magma with 'we t' sia l and subsequent fractionation may be r esponsi b l e for the calcalkaline phases .Observations of stratigraphic relationships (in particular the contact between the supracrustals and the granitoids) coupled with the metamorphic and chemical studies, allow the construction of a preliminary model for the evolution of the Island Lake greenstone belt. The following sequential development is suggested: 1) a platform stage characterised by the subaqueous effusion of mafic to intermediate lavas of alternating tholeiitic and calc-alkaline affinities; 2) an edifice stage marked by the eruption of felsic calc-alkaline rocks; 3) an erosional stage characterised by the deposit~on of thick sequences of turbidite facies rocks; 4) the impingement of granitic masses into the margins of the greenstone belt, which was probably related to a downward warping of the supracrustal pilei 5) the erosion of sialic massifs surrounding and within the greenstone belt and of early supracrustal piles, to give the clastic upper unit.

Gypsy moths (Lymantria dispar) in the Niagara Region : population density variation, introduction of an entomopathogenic fungus (Entomophaga maimaiga) and occurrence of nuclear polyhedrosis virus

The gypsy moth, Lymantria dispar, a major defoliator of broad leaf trees, was accidentally introduced into North America in 1869. Much interest has been generated regarding the potential of using natural pathogens for biological control of this insect. One of these pathogens, a highly specific fungus, Entomophaga maimaiga, was accredited with causing major epizootics in populations of gypsy moth across the north-eastern United States in 1989 and 1990 and is thought to be spreading northwards into Canada. This study examined gypsy moth population densities in the Niagara Region. The fungus, .E.. maimaiga, was artificially introduced into one site and the resulting mortality in host populations was noted over two years. The relationship between fungal mortality, host population density and occurrence of another pathogen, the nuclear polyhedrosis virus (NPV), was assessed. Gypsy moth population density was assessed by counting egg masses in 0.01 hectare (ha) study plots in six areas, namely Louth, Queenston, Niagara-on-the-Lake, Shorthills Provincial Park, Chippawa Creek and Willoughby Marsh. High variability in density was seen among sites. Willoughby Marsh and Chippawa Creek, the sites with the greatest variability, were selected for more intensive study. The pathogenicity of E. maimaiga was established in laboratory trials. Fungal-infected gypsy moth larvae were then released into experimental plots of varying host density in Willoughby Marsh in 1992. These larvae served as the inoculum to infect field larvae. Other larvae were injected with culture medium only and released into control plots also of varying host density. Later, field larvae were collected and assessed for the presence of .E.. maimaiga and NPV. A greater proportion of larvae were infected from experimental plots than from control plots indicating that the experimental augmentation had been successful. There was no relationship between host density and the proportion of infected larvae in either experimental or control plots. In 1992, 86% of larvae were positive for NPV. Presence and intensity of NPV infection was independent of fungal presence, plot type or interaction of these two factors. Sampling was carried out in the summer of 1993, the year after the introduction, to evaluate the persistence of the pathogen in the environment. Almost 50% of all larvae were infected with the fungus. There was no difference between control and experimental plots. Data collected from Willoughby Marsh indicated that there was no correlation between the proportion of larvae infected with the fungus and host population density in either experimental or control plots. About 10% of larvae collected from a nearby site, Chippawa Creek, were also positive for .E.. maimaiga suggesting that low levels of .E.. maimaiga probably occurred naturally in the area. In 1993, 9.6% of larvae were positive for NPV. Again, presence or absence of NPV infection was independent of fungal presence plot type or interaction of these two factors. In conclusion, gypsy moth population densities were highly variable between and within sites in the Niagara Region. The introduction of the pathogenic fungus, .E.. maimaiga, into Willoughby Marsh in 1992 was successful and the fungus was again evident in 1993. There was no evidence for existence of a relationship between fungal mortality and gypsy moth density or occurrence of NPV. The results from this study are discussed with respect to the use of .E.. maimaiga in gypsy moth management programs.

The pancreatic islet system of the rock bass /|nby Edward Francis Squires. -- 260 St. Catharines, Ont. : [s. n.],

The endocrine pancreas of the rock bass (Ambloplites rupestris) was examined by light and electron microscopy. Two cell types with staining properties similar to mammalian A and B cells, and a third, non-staining cell type were found in the spherical pancreatic islets that were surrounded by a connective tissue capsule and embedded in two small masses of exocrine tissue. From an analysis of the ultrastructure of the A and B cells, a secretory cycle for each of these cell types was proposed. The secretory cycle of the A cell consisted of three well defined stages: (1) A cell production stage: during which A granule formation occurred in the sacs of the Golgi apparatus and the cell was characterized by the presence of numerous secretory granules, some elements of lamellar endoplasmic reticulum, and a homogeneously granular nucleus. The cytoplasm contained few distended cisternae, variable numbers of free ribosomes, microtubules and small vesicles. (2) A cell release stage: during which the release of A granules occurred and the cell usually contained several large distended cisternae and variable numbers of secretory granules. Granule release mechanisms included exocytosis, by which individual granules were released into the extracellular space after their membranes fused with the plasmalemma, and emiocytosis, by which one or more granules were released into a large cisterna whose membrane fused with the plasmalemma and formed a pore through which the cisternal contents passed out of the cell. (3) A cell reorganization stage: during which the changeover from the release stage to the production stage occurred and the reorganization of organelles and membrane structures took place. The cell contained few secretory granules and numerous small endoplasmic reticular cisternae. The cytoplasm exhibited less electron density than either of the other two stages. The A granule after formation underwent a series of morphological changes which were described in four numerically identified phases. The secretory cycle of the B cell consisred of two stages: (1) B cell production stage: during which the B granule formation occurred in the sacs of the Go1gi apparatus. The cell was characterized by an irregular outline, the presence of numerous secretory granules, and an irregularly shaped nucleus which contained variable amounts of clumped chromatin. The cytoplasm contained moderate amounts of lamellar endoplasmic reticulum studded with ribosomes, several small vesicles, and an active Go1gi apparatus. (2) B cell release stage: during which the release of B granules occurred. The cell contained a rounded nucleus with dispersed chromatin, several distended endoplasmic reticular cisternae and a variable number of secretory granules. Granule release occu~ by emiocytosis and exocytosis similar to that found for the A cell.

Diversity among bacteria causing blotch disease on the commercial mushroom, agaricus bisporus /

A total of 251 bacterial isolates were isolated from blotched mushroom samples obtained from various mushroom farms in Canada. Out of 251 stored isolates, 170 isolates were tested for pathogenicity on Agaricus bisporus through mushroom rapid pitting test with three distinct pathotypes observed: dark brown, brovm and yellow/yellow-brown blotch. Phenotypic analysis of 83 isolates showed two distinct proteinase K resistant peptide profiles. Profile group A isolates exhibited peptides with masses of 45, 18, 16 and 14 kDa and fiirther biochemical tests identified them as Pseudomonasfluorescens III and V. Profile group B isolates lacked the 16-kDa peptide and the blotch causing bacterial isolates of this group was identified as Serratia liquefaciens and Cedecea davisae. Comparative genetic analysis using Amplified Fragment Length Polymorphism (AFLP) on 50 Pseudomonas sp. isolates (Group A) showed that various blotch symptoms were caused by isolates distributed throughout the Pseudomonas sp. clusters with the exception of the Pseudomonas tolaasii group and one non-pathogenic Pseudomonas fluorescens cluster. These results show that seven distinct Pseudomonas sp. genotypes (genetic clusters) have the ability to cause various symptoms of blotch and that AFLP can discriminate blotch causing from non-blotch causing Pseudomonasfluorescens. Therefore, a complex of diverse bacterial organisms causes bacterial blotch disease

Isolation and analysis of a corprinus cinereus DNA fragment showing homology to a fimbrial cDNA from ustilago violacea

Surface proteinaceous fibrils, termed fimbriae, were first identified on gram negative bacteria in the 1940s. Fungal fimbriae, discovered some 25 years later, are found on members of all fungal classes. In the present study, polyclonal antiserum raised against the fimbrial proteins of U. vio/acea were used in order to identify antigenically related proteins from Coprinus cinereus and Schizophy//um commune. Two polypeptides with molecular masses of 37 and 39 kDa from C. cinereus were observed and confirm earlier results. A single previously unidentified 50 kDa polypeptide in S. commune crossreacted with the antiserum. The 50 kDa protein was found to consist of 3 isoforms with isoelectric points ranging from 5.6 to 5.8. A fimbrial cDNA derived from U. vio/acea was used to identify DNA restriction fragments from C. cinereus and S. commune showing homology to the fimbrial transcript of U. vio/acea. Heterologous hybridization with this cDNA was used in order to screen a C. cinereus genomic DNA library. A single clone, A2-3A, with a 14 kbp insert showed strong homology to the pfim3-1 cDNA. The region of homology, a 700 bp Xba I fragment, was subcloned into pUG19. This plasmid was refered to as pXX8. DNA sequence determinations of pXX8 and adjacent fragments from A2-3A suggested that the cloned DNA was a portion of the rONA repeat encoding the small subunit rRNA. DNA sequence analysis of pfim3-1 yielded an incomplete open reading frame. The predicted amino acid sequence codes for a 206 amino acid, 22 kDa polypeptide which contains a domain similar to a transmembrane domain from rat leukocyte antigen, GDS3. As well, an untranslated 576 nucleotide domain showed 81 % homology to pXX8 and 830/0 homology to the 188 rRNA sequence of Ustilago maydis. This sequence was found adjacent to a region of adenine-thymine base pairs presumed to represent the polyadenylation sequence of the fimbrial transcript. The size and extent of homology is sufficient to account for the hybridization of pfim3-1 to rDNA. It is suggested that this domain represents a completely novel regulatory domain within eukaryotes that may enable the observed rapid regeneration of fimbriae in U. violacea.

Intracellular antioxidant and DNA repair enzymes as correlates of stress resistance and longevity in vertebrates

In animals, both stress resistance and longevity appear to be influenced by the insulin/insulin-like growth factor-l signaling (lIS) pathway, the basic organization of which is highly conserved from invertebrates to vertebrates. Reduced lIS or genetic disruption of the lIS pathway leads to the activation of forkhead box transcription factors, which is thought to upregulate the expression of genes involved in enhancing stress resistance, including perhaps key antioxidant enzymes as well as DNA repair enzymes. Enhanced antioxidant and DNA repair capacities may underlie the enhanced cellular stress resistance observed in long-lived animals, however little data is available that directly supports this idea. I used three. experimental approaches to test the association of intracellular antioxidant and DNA base excision repair (BER) capacities with stress resistance and longevity: (1) a comparison of multiple vertebrate endotherm species of varying body masses and longevities; (2) a comparison of long-lived Snell dwarf mice and their normallittermates; and (3) a comparison of hypometabolic animals undergoing hibernation or estivation with their active counterparts. The activities of the five major intracellular antioxidant enzymes as well as the two rate-limiting enzymes in the BER pathway, apurininc/apyrimidinic (AP) endonuclease and polymerase ~, were measured. These measurements were performed in one or more of the following: (1) cultured dermal fibroblasts; (2) brain tissue; (3) heart tissue; (4) liver tissue. My results indicate that antioxidant enzymes are not universally upregulated in association with enhanced stress resistance and longevity. I also did not find that BER enzyme activity was positively correlated with longevity, in an inter-species context, though there was evidence for enhanced BER in long-lived Snell dwarf mice. Thus, while there were instances in which enhanced antioxidant and BER enzyme activities were associated with increased stress resistance and/or longevity, this was not universally the case, indicating that other mechanisms must be involved. These results suggest the need to re-examine existing 'oxidative stress' hypotheses of longevity and probe further into the molecular physiology of longevity to discover its mechanistic basis.

Palynology and foraminiferal geochemistry of the Lower Pleistocene Olduvai Subchron (ca. 1.8 Ma) in DSDP Hole 603C, western North Atlantic

Marine palynology and benthic and planktonic foraminiferal geochemistry are combined to reveal long- and short-term (Milankovitch-scale) paleoceanographic changes across the upper half of the Olduvai Subchron (ca. 1.86--1.77 Ma, lower Pleistocene) in DSDP Hole 603C from the lower New Jersey continental rise. Planktonic foraminiferal Mg/Ca ratios reveal annual sea-surface temperatures between 14.5° and 25°C, whereas modern values vary between 16° and 20°e. Despite evidence of downslope transport in much of the studied interval, dinoflagellate cyst and acritarch assemblages appear to reflect fluctuating temperate to subtropical water masses. These assemblages comprise both neritic and oceanic species, and are marked by a transition upsection from warm conditions, dominated by Lingulodinium machaerophorum, Polysphaeridium zoharyi and Cymatiosphaera? invaginata, to cooler conditions dominated by Filisphaera filifera. Combining dinoflagellate cyst proxies with planktonic foraminiferal geochemistry allows downslope transport events to be recognized during glacial episodes, and events dominated by intensified bottom-water circulation during interglacial episodes. Sixtytwo in-situ dinoflagellate cyst and acritarch taxa were recorded including several not previously described.

Correlation of Protein Homeostasis With Maximum Lifespans in Endothermic Vertebrates

Cellular stress resistance has been shown to be highly correlated with longevity. However, the mechanisms conferring this stress resistance have yet to be identified. Maintenance of protein homeostasis is a critical component of cellular maintenance and stress resistance. Superior protein homeostasis capacities may thus underlie the greater stress resistance observed in longer-lived animals; however, little vertebrate data have been provided supporting this idea. I used two different experimental approaches to test the associations of protein homeostasis capacities with stress resistance and lifespan: 1) a comparison between a large set of vertebrate species with varying body masses and lifespans and 2) a comparison of long-lived Snell dwarf mice and their normal littermates. Protein homeostasis mechanisms including protein degradation activity, protein repair activity and molecular chaperone levels were examined. These measurements were performed in liver, heart and brain tissues, and isolated myoblasts. My results indicated that neither protein degradation nor protein repair were upregulated in association with enhanced stress resistance and longevity in an inter-species and intraspecies context. Furthermore, my results did show that there is a positive correlation between molecular chaperone levels and maximum lifespan (MLSP). However, there was no elevation of chaperone levels in the long-lived Snell dwarf mouse, indicating there are other mechanisms linked to their increased lifespan. Therefore, these results suggest that molecular chaperones are involved in increasing animal lifespan in an interspecies context.