Adaptation to water scarcity in glacier-dependent towns of the Indian Himalayas : impacts, adaptive responses, barriers, and solutions

Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning; and, (M. Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 195-203).Among the existing and projected impacts of climate change, impacts on water resources are expected to exacerbate the current and future threat of global water scarcity. Glacier-dependent societies are especially vulnerable to water scarcity due to the more pronounced effects of climate change on glacial systems that govern the water availability of these societies. In this thesis, water scarcity is examined as an impact of climate change in Dharamshala and Leh, two glacier-dependent towns of northern India, while recognizing that climate change is not the only factor causing depletion of water resources in these towns. In order to show the linkage between climate change and water scarcity, evidence is presented on changes occurring in the towns' local climate parameters such as snowfall, rainfall and temperature, as well as changes in the hydrology of the water bodies that make water available to these towns. This establishes that water scarcity in these towns has been induced not only by increasing demand, but also by decreasing supply of water. In light of the water scarcity facing these towns, an investigation of the measures taken by their local governments to address this issue is presented, which reveals that the primary adaptive response employed in both towns has been supply augmentation. The driver behind this response has been the pursuit of economic development to improve the standard of living of Dharamshala and Leh's constituents. It is argued that economic development as a driver has not been effective in inducing holistic adaptive responses to water scarcity. Additionally, climate change considerations have been largely absent in the policy/planning processes that govern water management in both towns, implying that the responses of Dharamshala and Leh to water scarcity have been influenced by the pursuit of short-term economic benefits in a local economy that fails to recognize the importance of the integrity of water resources to its sustenance. The perpetuation of unsustainable economic development and failure to account for climate change impacts in local water management points to the presence of several technological, structural, financial, and political barriers to the planning/implementation of holistic climate-centric strategies for adaptation to water scarcity in Dharamshala and Leh. Therefore, in the concluding part of this thesis, recommendations are offered to enable the local governments of Dharamshala and Leh to overcome these barriers.by Amruta Anand Sudhalkar.M.Eng.M.C.P

Treatment Algorithm in Proliferative Diabetic Retinopathy - From Protocols to the Real World

Diabetes mellitus is a global epidemic that leads to multiple macrovascular and microvascular complications. The complex interrelated pathophysiological mechanisms triggered by hyperglycemia underlie the development of diabetic retinopathy (DR). Proliferative diabetic retinopathy (PDR) is a microvascular complication, considered the main cause of irreversible blindness in patients of productive age in the world. On the other hand, diabetic macular edema (DME) remains the clinical feature most closely associated with vision loss. In general, both manifestations are due to an increase in inflammatory factors, such as specific pro-inflammatory prostaglandins, interleukins and angiogenic substances including vascular endothelial growth factor (VEGF). Laser photocoagulation and VEGF inhibitors have been shown to be effective in the treatment of PDR and DME. Currently, randomized protocols suggest that VEGF inhibitors therapy could displace laser photocoagulation in the treatment of PDR with and without the presence of DME. The ongoing discussion still prevails about the different treatment modalities for both retinal manifestations in real-world settings

Climate Change and Extreme Weather Adaptation Options for Transportation Assets in the Bay Area Pilot Project

The Metropolitan Transportation Commission (MTC), the San Francisco Bay Conservation and Development Commission (BCDC), the California Department of Transportation, District 4 (Caltrans) and San Francisco Bay Area Rapid Transit District (BART) have partnered on a collaborative sub- regional pilot project to assess adaptation options for a subset of key transportation assets vulnerable to sea level rise in Alameda County. This study builds on the Adapting to Rising Tides: Transportation Vulnerability and Risk Assessment Pilot Project which was completed in 2011 and identified representative critical transportation assets vulnerable to sea level rise. Both projects were funded by the Federal Highway Administration. The first study developed detailed risk profiles for approximately 30 transportation assets including road, rail and transit. Having identified the risks, and in order to move from assessment to action, three focus areas within Alameda County containing \u2018core\u2019 transportation assets and \u2018adjacent\u2019 community assets were selected for further study to ensure a thorough understanding of their vulnerabilities. Once that enhanced vulnerability had been assessed, a set of detailed, representative adaptation strategies have been developed as potential solutions to protect key bridge, highway, transit and community assets from future inundation

Pharmaceutics

The purpose of this study is to evaluate the visual acuity (VA) gain profiles between patients with drug-naive diabetic macular edema (DME) treated by dexamethasone implant (DEX-implant) and assess the baseline anatomical and functional factors that could influence the response to the treatment in real-life conditions. A retrospective, multi-center observational study included 129 eyes with drug-naive DME treated by DEX-implant. The Median follow-up was 13 months. Two groups of VA gain trajectories were identified-Group A, with 71% (n = 96) of patients whose average VA gain was less than five letters and Group B, with 29% (n = 33) of patients with an average gain of 20 letters. The probability of belonging to Group B was significantly higher in patients with baseline VA \textbackslashtextless 37 letters (p = 0.001). Ellipsoid zone alterations (EZAs) or disorganization of retinal inner layers (DRILs) were associated with a lower final VA (53.0 letters versus 66.4, p = 0.002) but without a significant difference in VA gain (4.9 letters versus 6.8, p = 0.582). Despite a low baseline VA, this subgroup of patients tends to have greater visual gain, encouraging treatment with DEX-implant in such advanced-stage disease. However, some baseline anatomic parameters, such as the presence of EZAs or DRILs, negatively influenced final vision

Scleral buckling surgery using multiple radial buckles: A valid option?

Purpose: To determine whether radial buckling surgery using two or more radial buckles with or without circumferential silicone tires is still a treatment option for rhegmatogenous retinal detachment (RRD) in the current scenario. Methods: Retrospective chart review. Patients with RRD with two or more horse-shoe tears with/without proliferative vitreoretinopathy up to grade C1 who underwent buckling surgery using at least two radial buckle segments without encircling bands or drainage and with at least a 3 year follow up were included in the study. Data collected included demographics, corrected distance visual acuity (CDVA) at baseline and final follow up, details of the examination, surgical procedure(s) and complications noted, if any. Appropriate statistical analysis was done. Statistical significance was set at p < 0.05. Outcome measures: Proportion of patients who had an attached retina at final follow up, improvement in CDVA and complications. Results: 25 patients (25 eyes; 12 males and 13 females; 9 pseudophakic) were included. Median age: 35.15 ± 8.32 years. Median baseline CDVA: 1.97 ± 1.12 logMAR. Median final CDVA: 0.65 ± 0.37 logMAR (significant improvement). Most common presenting complaint was decreased vision (87.5%). Number of radial buckle segments placed varied between 2 and 4 per eye. One patient required vitrectomy for persistent retinal detachment. One required buckle removal for infection 5 years after the primary procedure. One patient required strabismus surgery. Median follow up: 12.25 years ± 2.14 years. None of the other patients had any complications. Conclusion: Radial buckling surgery (two or more segments) is a reasonably safe and valid alternative to vitrectomy for RDs with multiple breaks in different planes. Keywords: Radial buckle, Scleral buckling, Rhegmatogenous retinal detachmen

Minimal surgery for tractional retinal detachment secondary to branch retinal vein occlusion: a case report

Abstract Background Tractional retinal detachment secondary to retinal vein occlusion is a complex entity that can be extremely difficult to manage due to an intricate association of the retinal tissue with the fibrovascular proliferation, making vitreous dissection an extraordinarily difficult procedure. Minimal surgery without endo-tamponade can reduce recovery time and avoid complications of surgery, which in some cases can lead to blindness and even phthisis. Case presentation A 64-year-old Indian woman presented with progressive worsening of vision (right eye) due to fovea involving tractional retinal detachment secondary to supero-temporal branch retinal vein occlusion. After anterior, core and peripheral vitrectomy, the epicenter of the fibrous bridge causing foveal split was identified and released. The corrected distance visual acuity improved from 6/60 pre-operatively to 6/12 post-operatively. At the 5-year follow-up, the patient remains stable both anatomically and visually. Conclusions This case illustrates how careful identification of the epicenter of traction helps maximize visual gain in patients with minimal risk of iatrogenic retinal tears and eliminates the need for endo-tamponade with either gas or silicone oil. Minimal surgery for tractional detachment provides excellent visual gains with minimal risks in select cases

Intravitreal dexamethasone implant for recalcitrant cystoid macular edema secondary to retinitis pigmentosa: a pilot study

cited By 0International audienceBackground: To determine the utility of the intravitreal dexamethasone implant as therapy for cystoid macular edema (CME) secondary to retinitis pigmentosa (RP) recalcitrant to carbonic anhydrase inhibitor therapy over 2 years as a pilot study. Methods: This was a prospective case series. Patients who showed either an incomplete or no response to topical dorzolamide for at least 1 month and oral acetazolamide therapy for at least 15 days were recruited for the study with informed consent. A complete anterior and posterior segment examination was performed including fundus fluorescein angiography (FFA), optical coherence tomography scan (OCT) and electroretinogram to confirm the diagnosis. The dexamethasone implant was injected using a standardized technique. Follow ups were scheduled on days 1, 7, and 30 and then monthly thereafter for 2 years. The primary outcome measure was the change in corrected distance visual acuity (CDVA) and central subfield thickness (CST) at months 1, 6, 12, 18, and 24. The secondary outcome measure was complications, if any. Appropriate statistical analysis was done. Results: Five patients (two males; six eyes; median age 49 years) were recruited for the study. All patients required at least two injections over 2 years. All patients demonstrated significant improvement in CDVA (p = 0.004) as well as CST measurements (p = 0.0038) over 2 years. No complications were noted. Conclusion: The intravitreal dexamethasone implant provides significant improvement in CDVA and CST measurements in patients with recalcitrant CME secondary to RP. © 2017, Springer-Verlag Berlin Heidelberg

Retinal circulation and its role in macular disorders in patients without systemic disease

<b>AIM:</b> To determine whether retinal circulatory changes play a role in the pathogenesis of macular disorders in patients who are otherwise healthy.<b>METHODS:</b>Patients with macular disorders that required angiographic imaging were included in this prospective case series. After a complete ocular exam, fluorescein angiography was performed using a standardized technique on the HRA-II (Heidelberg Engineering, Heidelberg, Germany) with special focus on the posterior pole. Only patients with good quality images were included in the analysis. Circulatory parameters recorded included the arm-choroid time, choroid-retinal artery, and finally the retinal artery-vein time. Zonal asymmetry (between the upper and lower zones divided by a line passing through the centre of the fovea) in transit times, if any was also noted. Appropriate statistical analysis was done. Circulation times were compared with age matched historical controls. Changes in retinal dye transit times relative to historical age matched controls, if any, were noted and compared between various disorders.<b>RESULTS:</b>A total of 156 eyes of 156 patients (120 males) were included in the study. Mean age:49.14±14.93y. Macular disorders studied were age related degeneration, polypoidal vasculopathy, central serous chorioretinopathy (CSCR) and parafoveal telangiectasia. Delayed circulation time was noted in CSCR patients only.<b>CONCLUSION:</b>CSCR patients appear to have delayed arterial filling, retinal circulatory disturbances do not seem to contribute to the pathogenesis of other macular disorders