Restoring the Lost Fishery: An Environmental History of Northern Nevada\u27s Pyramid Lake and Lower Truckee River Fishery

This thesis focuses on fisheries managers’ efforts to restore native cutthroats to northern Nevada’s Pyramid Lake for recreation, and the Paiutes’ battle to preserve them as a means of livelihood. Their efforts to reconstruct the fishery revealed the implausibility of environmental restoration, but more importantly underlined the motivations necessary to attempt it. Chapter 2 describes how the Pyramid Lake Lahontan cutthroat— historically an important subsistence resource for Northern Paiutes— were initially exploited for profit in the late 1800s and early 1900s, and gradually destroyed as agricultural interests diverted the Truckee River’s water and industrial pollution contaminated the trout’s aquatic habitat. Fisheries managers in Nevada turned to artificial propagation to meet the demands of fishermen and replace the native fish industrialization destroyed. The Nevada Fish and Game Commission experimented with non-native introductions and like most of the West became proponents of rainbow trout and their recreational potential. Chapter 3 narrates a history of the Nevada Fish and Game Commission’s project to restore trout to Pyramid Lake in the 1950s and 1960s after its native cutthroat became extinct in the early 1940s. For the Commission, restoring Pyramid Lake meant establishing trout and salmon populations— native or not— to feed the growing outdoor tourism industry. While the Commission made plans to restore natural spawning runs, these were unsuccessful, and the Commission relied on stocking the lake to maintain the fishery. However, these experiments failed and eventually cutthroats from other lakes in Nevada proved better occupants of the lake. Chapter 4 describes the native cutthroat’s role in the water debate carried out in government agencies and in the courts in the 1970s and 1980s to decide whether or not water diverted from the Truckee for agriculture should be returned to the Paiutes to support their shrinking lake and dwindling fishery. Environmentalist groups like the Sierra Club joined the Paiutes in their effort to gain water that would allow for the native fishery’s restoration. Their vision clashed with that of agriculturists who feared losing water they depended on for their crops. However, after a lengthy struggle, the Paiutes won an important victory toward preserving their lake

Empowerment through religious practice: a study of the medieval female pilgrim.

In a world run by men and religion, medieval women still found ways to proclaim their religious devotion. Though embarking on pilgrimage provided many specific (and sometimes dangerous) challenges for women, many still found ways to pay homage to the sacred, both at home and abroad. A closer look at the prayer books of German nuns, decorated with woodcut printed images and hand sewn elements will give insight to the aspect of imagined pilgrimage, a method available to women unable to partake in the physical journey due to their enclosed monastic lifestyle. Furthermore, an investigation of “Blood and Body” practices paired with the gruesome renditions of the crucifixion depicted by nuns in prayer books will show how women sought to experience the life and suffering of Christ, even when unable to walk where he walked. In contrast, Examining the life story of Margery Kempe, through the original copy of her autobiography will give understanding on what life was like for a journeying female pilgrim. This study will explore the roles women played in religion, both through struggle and empowerment, as they sought their own pilgrimage experiences

How far does the Work Discussion Method lend itself to facilitating change, to solve specific problems in work settings?

The aims of the study are firstly to investigate the suitability of the work discussion method as a consultancy change intervention in solving specific work issues in the organisational context of public sector services, and secondly to consider the viability of work discussion as a research method. This study has little substantiating research precedence to draw on and as such is one of discovery and understanding. The work discussion method is a systematic experiential small group process founded on the principle of the importance of emotional experiences, both conscious and unconscious, of work and the workplace in shaping understandings of role and of organisational life. This consultancy application of work discussion is a process of reflecting on specific issues with the intent of evoking a changed state in either thinking and or changed behaviours. As a method it is both concerned with individual learning and with shared learning. This is a small in-depth qualitative study following the principles of grounded theory and informed by systems psychodynamic theory. The research participants of this study come from a range of children’s and young people’s education and welfare services, predominantly in the public sector but also including one partner service from the voluntary sector. The findings of this study suggest that the word discussion method when applied as a consultancy change intervention has merit. The research participants during the life of the research study made notably changes to their understandings and or behaviours in their work situations

The growth of short fatigue cracks in titanium and aluminium alloys

An investigation has been made of the growth of An investigation has been made of the growth of short fatigue cracks in aluminium and titanium alloys, with special emphasis on the effects of microstructure. For the commercial aluminum alloys examined (7010 and 2014A) a degradation in short fatigue crack resistance accompanied an increase in the degree of ageing, as is commonly reported for long, through thickness cracks. The short cracks however, were seen to propagate at substantially faster rates than conventional, long cracks at the same apparent applied ΔK and R - ratio. The similar, faceted fracture produced for both types of crack suggests that the same propagation mechanism was operative, despite the differences in growth rate. Discontinuous growth was observed for microstructurally short cracks, associated with the crack tip being held up over large numbers of cycles at grain boundaries both at the surface and in the interior of the specimen. The discontinuous nature of propagation and the anomalously fast growth continued until the maximum plastic zone size ahead of the crack tip approximated to the grain size of the material. At greater crack depths propagation rates, at equivalent ΔKs, for long, through thickness cracks and short cracks showed reasonable agreement, small discrepancies being explained in terms of the variation in closure contribution for the two types of crack. Similar propagation characteristics were observed for the two titanium alloys studied (IMI 318 and IMI 550) with substantially faster propagation for microstructurally short cracks than for long cracks at equivalent ΔKs. In contrast to long crack behaviour however, an increase in grain size resulted in a deterioration in short crack propagation resistance. The microstructure which was found to be the most resistant to the growth of short cracks consisted of fine primary α and transformed β grains with the volume fraction of each type of α approximately equal. The grain boundaries between the two distinct α-morphologies were seen to be particularly effective in reducing the propagation rate. In contrast, a coarse, aligned, Widmanstätten α-morphology exhibited the worst resistance to short crack growth. Even though colony and prior β grain boundaries were useful in retarding crack growth, propagation across packets of Widmanstätten laths was very rapid. Crack shape effects were considered to be important. A study was made to assess the variation in crack shape and the effect on crack propagation, particularly in non-equiaxed microstructures. Cracks with depths approximating to the grain size were seen to vary significantly in shape, though they all eventually took a semi-elliptical form, with half surface length/ depth (a/c) ratios between 1.0 and 0.8, at greater crack depths. It is suggested that a better correlating parameter for short crack growth is crack area rather than surface crack length which is commonly used at present. In this way, the effects of crack shape can be accommodated

CoorsTek- Spine Discectomy

The objective is to design improved instrumentation for performing a spine discectomy. In particular, the instrument should remove the nucleus pulposus without damaging the annulus in order to prepare the spine disc for the insertion of an artificial spacer. As more nucleus pulposus is removed from the disc, the spine will fuse more quickly and completely after the artificial spacer is inserted. The current process involves removing the nucleus pulposus piece by piece with pituitary rongeurs. This process is slow and often incomplete

Cartas sobre o estudo e a utilidade da história

Trechos selecionados e traduzidos por Arthur Alfaix Assis. Texto original em The Works of Lord Bolingbroke, Vol. II, Philadelphia: Carey andHart, 1841, p. 173-334

The growth of short fatigue cracks in titanium and aluminium alloys

An investigation has been made of the growth of An investigation has been made of the growth of short fatigue cracks in aluminium and titanium alloys, with special emphasis on the effects of microstructure. For the commercial aluminum alloys examined (7010 and 2014A) a degradation in short fatigue crack resistance accompanied an increase in the degree of ageing, as is commonly reported for long, through thickness cracks. The short cracks however, were seen to propagate at substantially faster rates than conventional, long cracks at the same apparent applied ΔK and R - ratio. The similar, faceted fracture produced for both types of crack suggests that the same propagation mechanism was operative, despite the differences in growth rate. Discontinuous growth was observed for microstructurally short cracks, associated with the crack tip being held up over large numbers of cycles at grain boundaries both at the surface and in the interior of the specimen. The discontinuous nature of propagation and the anomalously fast growth continued until the maximum plastic zone size ahead of the crack tip approximated to the grain size of the material. At greater crack depths propagation rates, at equivalent ΔKs, for long, through thickness cracks and short cracks showed reasonable agreement, small discrepancies being explained in terms of the variation in closure contribution for the two types of crack. Similar propagation characteristics were observed for the two titanium alloys studied (IMI 318 and IMI 550) with substantially faster propagation for microstructurally short cracks than for long cracks at equivalent ΔKs. In contrast to long crack behaviour however, an increase in grain size resulted in a deterioration in short crack propagation resistance. The microstructure which was found to be the most resistant to the growth of short cracks consisted of fine primary α and transformed β grains with the volume fraction of each type of α approximately equal. The grain boundaries between the two distinct α-morphologies were seen to be particularly effective in reducing the propagation rate. In contrast, a coarse, aligned, Widmanstätten α-morphology exhibited the worst resistance to short crack growth. Even though colony and prior β grain boundaries were useful in retarding crack growth, propagation across packets of Widmanstätten laths was very rapid. Crack shape effects were considered to be important. A study was made to assess the variation in crack shape and the effect on crack propagation, particularly in non-equiaxed microstructures. Cracks with depths approximating to the grain size were seen to vary significantly in shape, though they all eventually took a semi-elliptical form, with half surface length/ depth (a/c) ratios between 1.0 and 0.8, at greater crack depths. It is suggested that a better correlating parameter for short crack growth is crack area rather than surface crack length which is commonly used at present. In this way, the effects of crack shape can be accommodated

High resolution radio observations of the colliding-wind binary WR140

Milli-arcsecond resolution Very Long Baseline Array (VLBA) observations of the archetype WR+O star colliding-wind binary (CWB) system WR140 are presented for 23 epochs between orbital phases 0.74 and 0.97. At 8.4 GHz, the emission in the wind-collision region (WCR) is clearly resolved as a bow-shaped arc that rotates as the orbit progresses. We interpret this rotation as due to the O star moving from SE to approximately E of the WR star, which leads to solutions for the orbit inclination of 122+/-5 deg, the longitude of the ascending node of 353+/-3 deg, and an orbit semi-major axis of 9.0+/-0.5 mas. The distance to WR140 is determined to be 1.85+/-0.16 kpc, which requires the O star to be a supergiant. The inclination implies the mass of the WR and O star to be 20+/-4 and 54+/-10 solar masses respectively. We determine a wind-momentum ratio of 0.22, with an expected half-opening angle for the WCR of 63 deg, consistent with 65+/-10 deg derived from the VLBA observations. Total flux measurements from Very Large Array (VLA) observations show the radio emission from WR140 is very closely the same from one orbit to the next, pointing strongly toward emission, absorption and cooling mechanism(s) that are controlled largely by the orbital motion. The synchrotron spectra evolve dramatically through the orbital phases observed, exhibiting both optically thin and optically thick emission. We discuss a number of absorption and cooling mechanisms that may determine the evolution of the synchrotron spectrum with orbital phase.Comment: Accepted by ApJ, to appear in v623, April 20, 2005. 14 pages, 13 figs, requires emulateapj.cls. A version with full resolution figs can be obtained from http://www.drao.nrc.ca/~smd/preprint/wr140_data.pd