Perspectiva del Rubro Energ´etico en Bolivia y Gas Natural

El proceso de reformas econ´omicas y estructurales en Latinoam´erica destaca a Bolivia, que ya en los a˜nos 80 iniciaba elcamino de “reducci´on del Estado”, resultando de esto, transformaciones que infringieron consecuencias en su desarrollo socioecon´omico, en particular en el sectorenerg´etico y el de la sostenibilidad

Energy Transition Planning with High Penetration of Variable Renewable Energy in Developing Countries: The Case of the Bolivian Interconnected Power System

The transition to a more environmentally friendly energy matrix by reducing fossil fuel usage has become one of the most important goals to control climate change. Variable renewable energy sources (VRES) are a central low-carbon alternative. Nevertheless, their variability and low predictability can negatively affect the operation of power systems. On this issue, energy-system-modeling tools have played a fundamental role. When exploring the behavior of the power system against different levels of VRES penetration through them, it is possible to determine certain operational and planning strategies to balance the variations, reduce the operational uncertainty, and increase the supply reliability. In many developing countries, the lack of such proper tools accounting for these effects hinders the deployment potential of VRES. This paper presents a particular energy system model focused on the case of Bolivia. The model manages a database gathered with the relevant parameters of the Bolivian power system currently in operation and those in a portfolio scheduled until 2025. From this database, what-if scenarios are constructed allowing us to expose the Bolivian power system to a set of alternatives regarding VRES penetration and Hydro storage for that same year. The scope is to quantify the VRES integration potential and therefore the capacity of the country to leapfrog to a cleaner and more cost-effective energy system. To that aim, the unit-commitment and dispatch optimization problem are tackled through a Mixed Integer Linear Program (MILP) that solves the cost objective function within its constraints through the branch-and-cut method for each scenario. The results are evaluated and compared in terms of energy balancing, transmission grid capability, curtailment, thermal generation displacement, hydro storage contribution, and energy generation cost. In the results, it was found that the proposed system can reduce the average electricity cost down to 0.22 EUR/MWh and also reduce up to 2.22 × 106 t (96%) of the CO2 emissions by 2025 with very high penetration of VRES but at the expense of significant amount of curtailment. This is achieved by increasing the VRES installed capacity to 10,142 MW. As a consequence, up to 7.07 TWh (97%) of thermal generation is displaced with up to 8.84 TWh (75%) of load covered by VRES

Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to <90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], >300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years

Decades in crisis: adapting a social-ecological framework to assess structural elements impacting asthma rates in the South Bronx

Disturbingly high rates of asthma-related hospitalizations have been documented in the South Bronx for several decades. The crisis has been typified by structural violence, health inequity, and disproportionate exposure to environmental harms, with the disease burden of poorly controlled asthma falling primarily on socioeconomically vulnerable racial and ethnic minorities. This review adapts the Social-Ecological Model (SEM) as a theory-based framework to critically analyze disparities in asthma care and control in the South Bronx. The analysis is grounded in historical considerations of structural violence, particularly the legacy of brownfields, toxic dumping, backroom politics and social arrangements that perpetuate disparities in medical care and health. This model can guide the development of multi-level interventions, including the sustainable medical management of asthma, particularly in the context of the ongoing asthma crisis in the South Bronx and its more recent disastrous overlap with the COVID-19 outbreak that has devastated New York City

Gynecological and obstetrical outcomes after laparoscopic repair of a cesarean scar defect in a series of 38 women

OBJECTIVE: To evaluate gynecological and obstetrical outcomes, as well as remaining myometrial thickness, after laparoscopic repair of a cesarean scar. DESIGN: Observational study and prospective evaluation of the remaining myometrium before and after repair. SETTING: Academic department in a university hospital. PATIENT(S): A series of 38 symptomatic women with cesarean scar defects and remaining myometrial thickness of less than 3 mm, according to magnetic resonance imaging. INTERVENTION(S): Laparoscopic repair of the defect. MAIN OUTCOMES MEASURE(S): Increase in myometrial thickness at the site of cesarean section, gynecological and obstetrical outcomes, and histological analysis of the defect after excision. RESULT(S): The mean thickness of the myometrium increased significantly from 1.43 ± 0.7 mm before surgery to 9.62 ± 1.8 mm after surgery. All but three patients were free of symptoms. Among the 18 women with infertility, eight (44%) became pregnant and delivered healthy babies by cesarean section at 38-39 weeks of gestation. Histological analysis, performed in all 38 cases, revealed the presence of endometriosis in eight women (21.1%). Muscle fiber density was significantly lower compared with adjacent myometrium. CONCLUSION(S): In symptomatic women with residual myometrial thickness of less than 3 mm who wish to conceive, laparoscopic repair could be considered an appropriate approach. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved. KEYWORDS: Cesarean scar defect; hysteroscopy; laparoscopic repair; myometrial thickness; nich

Energy transition planning in developing countries: The case of Bolivian interconnected power system

The transition to a more environmentally friendly energy matrix has become one of the most important goals to control the climate change. Variable renewable energy sources (VRES) are a central low-carbon alternative but their variability and lower predictability require a flexible power system capable of balancing the variations. The aim of this paper is to determine a possible transition pathway to reach high penetrations of non-conventional renewable sources for Bolivia. To that aim, a Bolivian long-term scenario (2050 horizon) is developed based on the international targets, with the purpose to distribute economic resources optimally in the next 30 years. This is achieved by combining a unitcommitment and dispatch model with the forecast demand for the upcoming years, the already-known power system plan for the Bolivian system (5 years), and various scenarios of VRES deployment. For each scenario, the flexibility of the power generation system is evaluated in terms of energy balancing, transmission grid, system inertia, ancillary services requirement, and energy generation cost. Results indicate a need to add 8.31 GW of transmission lines, increase storage capacity, and enhanced ancillary services up to 73.31TWh (in particular frequency containment reserve) in the next 30 years. Finally, the environmental and economic gains are evaluated with comparison to the baseline it is found that the proposed system can reduce 62% of the CO2 emissions by 2050 with high penetration of VRES. This will result into significant economic savings for the country by enhancing natural gas exportations.Energy transition planning in developing countries: The case of Bolivian interconnected power syste

Techno-economic evaluation of rural electrification in Bolivia: lessons learned from the “El Espino” micro-grid

peer reviewedIn the last ten years, Bolivia has gone through a period of economic growth and political stability without precedent in its 200 hundreds years of history. The national government has the ambition to reach a 100 % of rural electrification coverage by 2025. One of the key components for this purpose is the construction and operation of isolated hybrid micro-grids. In order to test this technology a pilot plant was built in September 2015 in the rural village of ‘El Espino’.The Objective of this study is the evaluation of the current operation strategy of this micro-grid and the implementation of the project. To that end, monitoring data is used, covering the period 1 of January of 2016 to 31 of july of 2017.The data analysis shows that the average PV efficiency is 9.34 %, the efficiency of the diesel generator is 31.4 % and the round trip efficiency of the battery is 74%. Using the data collected and the techno-economic information of the place, the operation cost of the system for the analyzed period is computed. Finally, an optimal dispatch model based in a mixed-integer linear programming (MILP) is used to find the optimal energy flows in the system that minimize the diesel consumption

Endometriosis and infertility

Endometriosis remains a very enigmatic and perplexing disease. The exact mechanism by which endometriosis causes infertility is still unclear. In the present paper, we will review possible mechanisms leading to subfertility or infertility in women with endometriosis and examine them according to location. Endometriosis in the pelvic cavity is a pathology associated with a general inflammatory response and should therefore be considered an inflammatory disease. Inflammatory changes affect the peritoneal fluid and hence the intratubal milieu, since the ampulla (where fertilization takes place) is exposed to peritoneal fluid through the fimbria. Any inflammatory change at this level may therefore impact fertilization and natural conception. The relationship between ovarian endometriomas and infertility may, of course, be explained by the presence of periovarian endometriosis. In the ovary, fibrosis observed in some cortical areas is induced by the inflammatory reaction caused by the presence of endometriomas. The association between fibrosis and a reduced ovarian reserve was demonstrated. Upregulated recruitment and the subsequent demise of early follicles may result in focal exhaustion of primordial follicles. Burn-out of early follicles by a local pelvic inflammatory environment caused by endometriomas may therefore be suggested. However, intraovarian inflammation, subsequent fibrosis and depletion of the ovarian reserve constitute another reason that should also be given due consideration. In addition, surgery should not be ruled out as a possible cause of ovarian reserve depletion. In conclusion, potential mechanisms leading to infertility are numerous, and while some of them remain hypothetical for now, others are supported by clear evidence. These possible mechanisms were reviewed in the present paper

Important role of collective cell migration and nerve fiber density in the development of deep nodular endometriosis.

Objective To evaluate deep nodular endometriotic lesions induced in baboons over 12 months and analyze collective cell migration and nerve fiber density. Design Morphologic and immunohistochemical analysis of endometriotic lesions induced in baboons over the course of 1 year. Setting Academic research unit. Animal(s) Three female baboons (Papio anubis). Intervention(s) Recovery of induced deep nodular endometriotic nodules from baboons. Main Outcome Measure(s) Evaluation of the morphology of glands by analysis of the center of lesions and the invasion front; immunohistochemical staining with Ki67, E-cadherin, and β-catenin for investigation of mitotic activity and cell-cell junctions, and with protein gene product 9.5 and nerve growth factor (NGF) for study of nerve fiber density (NFD). Result(s) All (100%) of the lesions were invasive 1 year after induction, compared with 42.29% after 6 months. Glands from the invasion front showed significantly reduced thickness but significantly higher mitotic activity. E-Cadherin and β-catenin expression were similar between the center and front. NFD was significantly higher in lesions induced after 1 year than after 6 months, and NGF expression was significantly lower in 1-year lesions than in 6-month lesions. Conclusion(s) Nodular endometriotic lesions induced in the baboon model were found to be significantly more invasive and innervated after 12 months than after 6 months. The invasive phenotype was highly expressed in glands at the invasion front, and our study suggests that nerve fibers play a role in the development of lesions as observed in women

Invasion process of induced deep nodular endometriosis in an experimental baboon model: similarities with collective cell migration?

OBJECTIVE: To determine the implications of collective cell migration in the invasion phenomenon observed in deep endometriotic lesions induced in a baboon model. DESIGN: Study of morphology and collective cell migration markers in invasive and noninvasive deep endometriotic lesions induced in a baboon model. Invasive lesions were defined as the presence of endometrial glands and stroma in surrounding organs, and a distinction was made between the center of the lesion (glands present in the main lesion) and the invasion front (glands present in surrounding organs). SETTING: Academic research unit. ANIMAL(S): Ten female baboons (Papio anubis). INTERVENTION(S): Recovery of induced deep nodular endometriotic nodules. MAIN OUTCOME MEASURE(S): Evaluation of the morphology of glands by analysis of noninvasive and invasive lesions (center of the lesion and invasion front); staining with specific antibodies (Ki67, E-cadherin, β-catenin) for immunohistochemical study of mitotic activity and cell-cell junctions. RESULT(S): Glands from invasive lesions, particularly from the invasion front, showed a significantly lower thickness coefficient, higher mitotic activity, and lower expression of E-cadherin and β-catenin than glands from noninvasive lesions and the center of invasive lesions. CONCLUSION(S): We report altered morphology, increased mitotic activity, and fewer adhesion molecules in invasive glands present in induced nodular endometriosis, particularly along the invasion front, suggesting that collective cell migration is involved in the invasion process of deep endometriotic lesions induced in a baboon model