Low-income communities in World Heritage Cities : revitalizing neighborhoods in Tunis and Quito

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Architecture, 2000.Includes bibliographical references (leaves 44-49).Since the 1970s, international preservation and funding agencies have promoted revitalization projects in developing countries aiming to, among other things, benefit low-income communities. For the most part, these projects have resulted in visibly improved physical spaces, reflecting upgraded infrastructure along with conservation of the architectural fabric. These outcomes are impressive in light of decades of neglect and decay. The impact on low-income residents, however, remains obscure. In what cases have the poor really benefited from these revitalization projects? Through what specific channels can low-income communities benefit from interventions? How have governments in these countries responded to the external pressure to benefit low-income residents given their often limited institutions and budgets? This thesis seeks address these questions. In particular, it aims to understand the conditions under which revitalization projects in historic cities of developing countries can benefit low-income communities. It begins by considering the evolution of international philosophy, following the shift from a central focus on monument preservation to that of urban revitalization, with a notable difference being the incorporation of social objectives in the latter phase. It then turns to exploring how these goals of revitalization have played out in two World Heritage Cities, Tunis and Quito. Findings indicate that low-income residents have indeed benefited from revitalization projects in both cases. Drawing from these experiences, this thesis reveals four common elements in the process through which this favorable outcome was achieved: 1) a significant component of public participation, 2) a semi-public development agency with operational flexibility and innovative financing strategies, 3) international catalysts in the form of World Heritage recognition and collaboration with international organizations and agencies, and 4) image improvement leading to a renewed self-image of the neighborhood. While these four elements by no means offer a template for success, they do indicate institutional structures that may support developing countries' efforts to reach the poor while revitalizing their cities.by T. Luke Young.S.M

A Hybrid Monitor Assisted Fault Injection Environment

Coordinated Science Laboratory was formerly known as Control Systems LaboratoryJoint Services Electronics Program / N00014-91-J-1116Tandem Computers, Inc.Department of the Navy, Office of the Chief of Naval Research / N00014-91-J-111

Barley foliage diseases, Field pea diseases

A. Experimental Notes. Barley foliage diseases: B. Scald: Effect of various fungicides. c. Scald: Response of cultivars to fungicides. D. Scald: Effect of seeding rate on infection and yield. E. Scald: Testing of fungicides S3308L. F. Net blotch: Potential yield losses. G. Net blotch: Screening fungicides. H. Spot type net blotch: Simulated stubble retention. I. Spot type net blotch: Potential yield losses. J. Powdery mildew: Effect of simulated stubble retention. K. Powdery mildew: Time of fungicide application. L. Powdery mildew: Comparing fungicides. M. Powdery mildew: Testing fungicide S3308L. N. Powdery mildew: Response to Erex in farmer\u27s crops. o. Disease development and yield in barley cultivars. P. Response to Bayleton in farmer\u27s crops. Q. Disease resistance in stage 4 barley cultivars. Field pea diseases R. Black spot: Seed dressing and spray timing. S. Field Pea disease survey

Collective modes and sound propagation in a p-wave superconductor: Sr2_2RuO4_4

There are five distinct collective modes in the recently discovered p-wave superconductor Sr$_2$RuO$_4$; phase and amplitude modes of the order parameter, clapping mode (real and imaginary), and spin wave. The first two modes also exist in the ordinary s-wave superconductors, while the clapping mode with the energy $\sqrt{2} \Delta(T)$ is unique to Sr$_2$RuO$_4$ and couples to the sound wave. Here we report a theoretical study of the sound propagation in a two dimensional p-wave superconductor. We identified the clapping mode and study its effects on the longitudinal and transverse sound velocities in the superconducting state. In contrast to the case of $^3$He, there is no resonance absorption associated with the collective mode, since in metals $\omega/(v_F |{\bf q}|) \ll 1$, where $v_F$ is the Fermi velocity, {\bf q} is the wave vector, and $\omega$ is the frequency of the sound wave. However, the velocity change in the collisionless limit gets modified by the contribution from the coupling to the clapping mode. We compute this contribution and comment on the visibility of the effect. In the diffusive limit, the contribution from the collective mode turns out to be negligible. The behaviors of the sound velocity change and the attenuation coefficient near $T_c$ in the diffusive limit are calculated and compared with the existing experimental data wherever it is possible. We also present the results for the attenuation coefficients in both of the collisionless and diffusive limits at finite temperatures.Comment: RevTex, 12 pages, 2 figures, Replaced by the published versio

Charge-spin correlation in van der Waals antiferromagenet NiPS3

Strong charge-spin coupling is found in a layered transition-metal trichalcogenide NiPS3, a van derWaals antiferromagnet, from our study of the electronic structure using several experimental and theoretical tools: spectroscopic ellipsometry, x-ray absorption and photoemission spectroscopy, and density-functional calculations. NiPS3 displays an anomalous shift in the optical spectral weight at the magnetic ordering temperature, reflecting a strong coupling between the electronic and magnetic structures. X-ray absorption, photoemission and optical spectra support a self-doped ground state in NiPS3. Our work demonstrates that layered transition-metal trichalcogenide magnets are a useful candidate for the study of correlated-electron physics in two-dimensional magnetic material.Comment: 6 pages, 3 figur

Single Top Quark Production via FCNC Couplings at Hadron Colliders

We calculate single top-quark production at hadron colliders via the chromo-magnetic flavor-changing neutral current couplings $\bar tcg$ and $\bar tug$. We find that the strength for the anomalous $\bar tcg$ ($\bar tug$) coupling may be probed to $\kappa_c / \Lambda = 0.092 {TeV}^{-1}$ ($\kappa_u / \Lambda = 0.026 {TeV}^{-1}$) at the Tevatron with $2 {fb}^{-1}$ of data and $\kappa_c / \Lambda = 0.013 {TeV}^{-1}$ ($\kappa_u / \Lambda = 0.0061 {TeV}^{-1}$) at the LHC with $10 {fb}^{-1}$ of data. The two couplings may be distinguished by a comparision of the single top signal with the direct top and top decay signals for these couplings.Comment: 18 pages, 6 figures, 3 table

Blood pressure vs altitude in hypertensive and non-hypertensive himalayan trekkers

Introduction: Determine blood pressure (BP) response to changes in altitude in Himalayan trekkers with and without hypertension (HTN). Methods: BP was measured in Lukla (2800m), Namche (3400m), and either Pheriche or Dingboche (4400m) on ascent and descent. Hypertensive subjects were defined by self-reported diagnosis of HTN. Results: Trekkers had HTN (H, n=60) or no HTN (NH, n=604). Of those with HTN, 50 (83%) took one or more BP medications including ACEIs/ARBs (n=35, 48%), Ca++ channel blockers (n=15, 22%), beta-blockers (n=9, 13%), thiazide diuretics (n=7, 10%), and others (n=5, 7%). At 2800m, systolic BP (SBP) and diastolic BP (DBP) were greater in the H group than in the NH group [mean SBP= 151mmHg (95% CI 145.4-155.7) vs 127mmHg (95% CI 125.5 128.0); mean DBP=88mmHg (95% CI 85.1-91.7) vs 80mmHg (95% CI 79.3-80.8)] and remained higher at both 3400m [mean SBP=150mmHg (95% CI 143.7-156.9) vs 127mmHg (95% CI 125.8-128.5); mean DBP=88mmHg (95% CI 84.3-90.8) vs 82mmHg (95% CI 80.7-82.5)] and 4400m [mean SBP=144mmHg (95% CI 136.7-151.7) vs 128mmHg (95% CI 126.4-129.5); mean DBP=87mmHg (95% CI 83.2-91.7) vs 82mmHg (95% CI 81.3-83.2)]. Between 2800m and 3400m, BP increased in 37% of trekkers, decreased in 25%, and did not change in 38%; from 3400m to 4400m, BP increased in 35% of trekkers, decreased in 26%, and did not change in 40%. Prevalence of severe hypertension (BP\u3e180/120mmHg) was similar across altitudes but higher in the H group (9%; 10%; 8% vs 0.7%; 0.6%, 0.3%) at 2800m, 3400m, and 4400m, respectively. No subjects reported symptoms of hypertensive emergency (chest pain, stroke, etc.). Conclusion: Blood pressure response to altitude is variable. High prevalence of severe hypertension in hypertensive trekkers warrants further study regarding BP control at high altitude

Projecting ozone hole recovery using an ensemble of chemistry-climate models weighted by model performance and independence

Calculating a multi-model mean, a commonly used method for ensemble averaging, assumes model independence and equal model skill. Sharing of model components amongst families of models and research centres, conflated by growing ensemble size, means model independence cannot be assumed and is hard to quantify. We present a methodology to produce a weighted-model ensemble projection, accounting for model performance and model independence. Model weights are calculated by comparing model hindcasts to a selection of metrics chosen for their physical relevance to the process or phenomena of interest. This weighting methodology is applied to the Chemistry-Climate Model Initiative (CCMI) ensemble to investigate Antarctic ozone depletion and subsequent recovery. The weighted mean projects an ozone recovery to 1980 levels, by 2056 with a 95 % confidence interval (2052-2060), 4 years earlier than the most recent study. Perfect-model testing and out-of-sample testing validate the results and show a greater projective skill than a standard multi-model mean. Interestingly, the construction of a weighted mean also provides insight into model performance and dependence between the models. This weighting methodology is robust to both model and metric choices and therefore has potential applications throughout the climate and chemistry-climate modelling communities

Half-quantum vortex and d-soliton in Sr2_2RuO4_4

Assuming that the superconductivity in Sr$_2$RuO$_4$ is described by a planar p-wave order parameter, we consider possible topological defects in Sr$_2$RuO$_4$. In particular, it is shown that both of the ${\hat d}$-soliton and half-quantum vortex can be created in the presence of the magnetic field parallel to the $a$-$b$ plane. We discuss how one can detect the ${\hat d}$-soliton and half-quantum vortex experimentally.Comment: 8 pages, 3 figure