Thesis (PH. D.)--Columbia university, 1920. / Vita. "Literature cited": p. 37-42. Also available in digital form on the Internet Archive Web site.

P. magnifica is an invasive freshwater bryozoan species which is native to the North America. The aim of this thesis is to ascertain the pace of the colonies' growth. The survey was carried out in three locations during twenty-one days in July 2018.

Bovine respiratory disease complex is the most common disease that causes sig-nificant economic loss, typically in feedlot cattle. Current treatment methods are focused on reducing inflammatory responses, control of airway reactivity and improvement of pulmonary functions without potential side effects. Neutrophils are the key contributors in acute lung inflammation. However, activated neutrophils live longer and cause exces-sive tissue damage upon migration into lungs. Therefore, modulation of their migration and lifespan are attractive approaches in treatment strategies of bovine respiratory dis-ease. Nanotechnology holds significant potential to design new compounds by our ability to manipulate at the nanoscale. Helical rosette nanotubes are a class of novel, biologi-cally inspired, water soluble and metal-free nanotubes. I used helical rosette nanotubes conjugated to arginine-glycine-aspartic acid (RGD-RNT) to study their effects on neu-trophil chemotaxis, cell signaling and apoptosis. Bovine neutrophils exposed to 5% RGD-RNT reduced their migration in response to fMLP (formyl-Methionyl-Leucyl-Phenylalanine), compared to the non-treated group (P<0.001). This inhibitory effect was the same as that of groups treated with ERK1/2 inhibitor (UO126) and p38 MAPK in-hibitor (SB239063). In addition, the phosphorylated ERK1/2 and p38 MAPK for the first time were quantified by sandwich ELISA to elucidate the mechanism of neutrophil mi-gration. The phosphorylation of both the ERK1/2 and p38 was inhibited at 5 minutes by RGD-rosette nanotubes (P<0.05). Furthermore, integrin ÑvÒ3 is possibly involved in mi-gration of bovine neutrophils. Moreover, RGD-RNT did not induce apoptosis of bovine neutrophils which was inversed by pre-exposing them to LPS for 30 minutes (P<0.001). These experiments provide the first evidence that RGD-rosette nanotubes suppress phos-phorylation of ERK1/2 and p38 MAPK and inhibit chemotaxis of bovine neutrophils.

Bovine respiratory disease complex is the most common disease that causes sig-nificant economic loss, typically in feedlot cattle. Current treatment methods are focused on reducing inflammatory responses, control of airway reactivity and improvement of pulmonary functions without potential side effects. Neutrophils are the key contributors in acute lung inflammation. However, activated neutrophils live longer and cause exces-sive tissue damage upon migration into lungs. Therefore, modulation of their migration and lifespan are attractive approaches in treatment strategies of bovine respiratory dis-ease. Nanotechnology holds significant potential to design new compounds by our ability to manipulate at the nanoscale. Helical rosette nanotubes are a class of novel, biologi-cally inspired, water soluble and metal-free nanotubes. I used helical rosette nanotubes conjugated to arginine-glycine-aspartic acid (RGD-RNT) to study their effects on neu-trophil chemotaxis, cell signaling and apoptosis. Bovine neutrophils exposed to 5% RGD-RNT reduced their migration in response to fMLP (formyl-Methionyl-Leucyl-Phenylalanine), compared to the non-treated group (P<0.001). This inhibitory effect was the same as that of groups treated with ERK1/2 inhibitor (UO126) and p38 MAPK in-hibitor (SB239063). In addition, the phosphorylated ERK1/2 and p38 MAPK for the first time were quantified by sandwich ELISA to elucidate the mechanism of neutrophil mi-gration. The phosphorylation of both the ERK1/2 and p38 was inhibited at 5 minutes by RGD-rosette nanotubes (P<0.05). Furthermore, integrin ÑvÒ3 is possibly involved in mi-gration of bovine neutrophils. Moreover, RGD-RNT did not induce apoptosis of bovine neutrophils which was inversed by pre-exposing them to LPS for 30 minutes (P<0.001). These experiments provide the first evidence that RGD-rosette nanotubes suppress phos-phorylation of ERK1/2 and p38 MAPK and inhibit chemotaxis of bovine neutrophils.

No description available.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

Important ecological processes happen over long periods of time and at the landscape scale. Effective conservation of biodiversity and management of natural resources and ecosystem services requires an understanding of these processes. Unfortunately, it is often impractical to conduct appropriate long-term, landscape-scale studies. Modelling offers an alternative approach. Complete ecosystems are too complex to model practically, but simulations of simplified systems provide useful insights of practical value. LandBaSE-P is an individual-based model for Puya hamata that provides information about impacts of fire on ecological processes in the páramo of the Reserva Ecológica El Ángel, Ecuador. Puya hamata is a flagship plant affected by fires and plays a key role in a number of ecological processes. This research found Puya hamata germinated much more frequently after fires, can form large aggregations of single recruitment cohorts, suffers very low mortality (with and without fires) once established, and lives up to 28 years. The spatial aggregation of Puya hamata plants reduced effective reproductive output, consistent with the theory that pollinator behaviour around large groups of Puya plants reduces cross-pollination, leading to inbreeding depression and poorer seed viability and germination. Puya hamata’s population structure can be an indicator of recent fire regime. LandBaSE-P simulations showed that population size is not affected by rare, long-distance seed dispersal. However, in the simulations of páramo grasslands, Puya relative germination is maintained in high numbers by burning. Puya hamata has an important role in ecology and biodiversity. The model LandBaSE-P is a complementary tool for conservation and sustainable land management. This thesis shows how fieldwork combined with laboratory studies and modelling, can provide a good understanding of complex dynamics of real-world populations, and generate ideas for management and future research.

Diss. (sammanfattning) Stockholm : Karol. inst., 2005. / Härtill 5 uppsatser.

E-rosette formation by human lymphocytes incubated with sheep red blood cells (sRBC) is inhibited by morphine. We studied the ability of the opiate antagonists naloxone and Tyr-MIF-1 (Tyr-Pro-Leu-Gly-NH2) to block this action. Active E-rosette formation by lymphocytes incubated with morphine was reduced from the control of 35.7±1.7% to 23.7±1.5% (p<0.001). Similarly, total E-rosette formation was reduced by morphine from the control of 65.8±1.3% to 53.2±2.9% (p<0.001). These effects were blocked by co-incubation of the lymphocytes with either Tyr-MIF-1 or naloxone (p<0.05). Tyr-MIF-1 was active (p<0.05) at concentrations as dilute as 10-13M. These results indicate that the neuropeptide Tyr-MIF-1 exerts an antiopiate effect at the human T-lymphocyte.

Pour la détermination des contraintes thermomécaniques au niveau du silicium, les capteurs piézorésistifs (en rosette) composés de 4nMOS et 4pMOS ont été développés et embarqués dans des produits de la microélectronique.Les relations caractéristiques liant les grandeurs piézorésistives, électriques et mécaniques ont été établies.La détermination des grandeurs piézorésistives nécessite un test de calibration effectué ici à l’aide d’une machine de flexion quatre-points. Cette machine a été conçue et fabriquée dans le cadre de cette thèse et permet d’appliquer une contrainte uniforme uni-axiale dans l’échantillon de silicium et de déterminer ainsi les trois coefficients piézorésistifs.Les capteurs intégrés sur différentes technologies telles que CMOS65, BiCMOS55, CMOS40, BSI140 et PIC25 ont été calibrés avec cette machine.Ces capteurs MOS ont été utilisés dans les cas d’études des contraintes induites par le TSV (technologie CMOS65), par la mise en boitier avec un empilement 3D (technologie CMOS65) et un empilement 2D (technologie BiCMOS55).Les résultats donnent des composantes de contraintes (σyy, σzz) qui ne sont pas en bonne corrélation avec les résultats de simulations. Les réponses électriques des MOS orientés à 90° (direction [010]) par rapport à l’axe des x (direction [100]) sont mises en question, car le coefficient (π12) obtenu à partir de ce MOS agit directement sur les deux composantes de contraintes.D’autre part, les variations de contraintes dans la zone des capteurs, les variabilités inter-puces et inter-plaques perturbent les résultats.Intégrées dans la même structure de test de la technologie CMOS40, différents composants ont été étudiés, notamment les transistors MOS rosette, la structure bandgap et les résistances poly-Si qui ont aussi été calibrés.Une étude de la contrainte thermomécanique induite par la mise en boitier de cette technologie a révélé un fort impact sur les réponses de sortie (mobilité des MOS, tension bandgap).Par une étude de minimisation paramétrique, cet impact a été réduit en agissant sur les dimensions géométriques des constituants et les propriétés matériaux de la résine de moulage.Ces résultats montrent que les MOS en rosette peuvent être utilisés comme capteurs de contraintes mais avec une efficacité limitée. L’utilisation des résistances actives comme capteurs de contraintes est donc envisageable. Par contre, ces MOS peuvent être utilisés pour déterminer l’impact des contraintes sur le fonctionnement de la puce. / For the thermomechanical stress assessment in silicon, piezoresistive sensors (in rosette) composed of 4nMOS and 4pMOS were developed and embedded into microelectronic products.The characteristic relations between piezoresistive, electrical and mechanical quantities were established.Piezoresistive quantities were identified thanks to a four-points bending calibration machine. This machine was designed and fabricated in the frame of this PhD and enables applying a known uniform uniaxial stress into silicon sample and then calculating the three piezoresistive coefficients.The sensors embedded into different technologies such as CMOS65, BiCMOS55, CMOS40, BSI140 and PIC25 were calibrated with this machine.These MOS sensors were used for studying stresses induced by TSV (CMOS65 technology), by packaging with 3D stacking (CMOS65 technology) and 2D stacking (BiCMOS55 technology).The results give stress components (σyy, σzz) which are not in a good agreement with simulation results. Electrical responses of the MOS oriented at 90° ([010] direction with respect to the x axis ([100] direction)) are questioned because the coefficients (π12) obtained from this MOS acts directly on the two components.In addition, stress variations in sensors area, as well as inter-chips and inter-wafers variabilities disturb the results.Integrated into the same test chip of the CMOS40 technology, different structures were studied, namely the MOS transistors, the bandgap structure and the poly-Si resistances which were also calibrated.For this technology, a study of thermomechanical stress induced by packaging revealed a significant impact on the output responses (MOS mobility, bandgap voltage). Through a minimization parametric study, this impact was reduced by controlling the geometrical dimensions of components and the material properties of the moulding compound.These results show that, MOS rosettes can be used as stress sensors but with a limited efficiency. The use of active resistances as stress sensors is therefore envisaged. However, these MOS can be used to study the impact of stresses on the chip operation.