Santiago Research Articles

Comparative Analysis of Very Reduced vs Full Dose BCG Treatment for High-Risk Non-Muscle Invasive Bladder Cancer: A Contemporary Experience from Chile.

Adjuvant bacillus Calmette-Guérin (BCG) is recommended for high-risk (HR) non-muscle invasive bladder cancer (NMIBC), but BCG shortages have led to exploration of reduced-dose regimens and shortened maintenance durations out of necessity, with limited data on treatment efficacy in Latin America. Oncological outcomes of HR-NMIBC patients treated with reduced (RD,1/4th dose) vs full dose (FD) BCG instillations of Danish Strain 1331 BCG. We performed a retrospective study of HR-NMIBC patients treated with BCG between 2003 and 2022 at our center in Santiago Chile. We stratified patients according to either RD (1/4th dose) or FD BCG. Univariate and multivariable Cox regression models were used to predict recurrence. Kaplan-Meier method was used to calculate survival estimates. Of a total of 200 patients, 116 (58%) had RD and 84 (42%) FD BCG. Median follow-up was 57 months (IQR: 29-100). Patients who received FD BCG had a lower risk of recurrence (HR: 0.41, 95% CI 0.22-0.74) and high-grade (HG)-recurrence (HR: 0.30, 95% CI 0.15-0.61; p = 0.001). More patients in the RD vs FD group progressed to MIBC (10/84 vs 2/116; p = 0.18). Additionally, patients were less likely to stop BCG treatment in the RD group compared to the FD group due to toxicity (5% vs 11%, p = 0.14). A 1/4th dose of Danish Strain 1331 BCG treatment was associated with worse recurrence free rate and HG-recurrence rate in our cohort. Patients with RD had lower discontinuation treatment rates due to a reduced toxicity profile. These findings would suggest that RD BCG would compromise oncological outcomes in HR-NMIBC patients.

Configurations for Four Urban Tree Species in the Santiago Metropolitan Region and Their Impact on the Environment According to CO2, PM2.5, Biogenic Volatile Organic Compounds and Water Resource Criteria

The rapid and disproportionate growth of many cities in South America, such as Santiago de Chile, has not included a design that considers the impact caused. Furthermore, industrial and housing growth has been based mainly on unsustainable economic criteria, attributing less importance to environmental criteria. This has caused problems related to global warming, pollution, water scarcity and health, especially harming populations with fewer resources. This study estimates and compares the impact of four tree species commonly used at the urbanization level, according to variables such as carbon dioxide (CO2), fine particulate matter (PM2.5), water resources, and biogenic volatile organic compounds (BVOCs). Then, we will use the variable PM2.5 to assess the trees’ impact on the population and their economic resources using these tree species as a method of capturing this pollutant. The results obtained will be used to determine which one of the four species is the most suitable in each type of space within the Metropolitan Region of Chile (small spaces, uncultivated areas, large spaces near industrial areas, areas with patients with breathing problems, etc.) according to three criteria: a comparison between species using the number of trees in the investigated territory; contrasting the species with the amount of social housing; and a comparison between the species according to the total number of dwellings.

Testing Housing Price Drivers in Santiago de Chile: A Hedonic Price Approach

Hedonic modelling is an empirical analysis technique that is widely used to review the housing market and unpack the main determinants of price. A correct determination of housing price drivers allows a weighted prediction of the value of each dwelling for sale or rent. This paper reviews the fundamental determinants of housing prices that have been published in the literature to see which ones have a better predictive fit for the case of the housing market in the city of Santiago, Chile. From a record of 456,000 property transactions, a dataset composed of 11 explanatory variables is elaborated. Through a semi-logarithmic regression, 4 variables that contribute to explaining the formation of housing prices in Santiago, Chile, are identified. The results indicate that the socioeconomic characterisation of urban areas where housing is traded, the price of copper on the London Metal Exchange, the mortgage interest rate, the age of residential buildings are the main drivers for the main drivers of prices in Santiago. Given the crisis of access to housing in Chile, the article provides relevant information for decision-makers in housing policy.

On subaltern urban historiography: Locating Nona Fernández’s Mapocho between decolonization and urban social movements

This article makes a triple intervention into discussions about the relationship between subaltern collective memory, urban historiography and urban social movements. First, and more theoretically, I argue that grassroots urban social movements require a corresponding history to unite people into a collective urban social agent. In short, there are no urban social movements without a shared urban history to bring them together. The cultural struggle over defining a city’s urban meaning is waged not only by material political fights, but also over how we represent the past of our cities. Second, I argue that ruling urban classes circulate and popularize their own urban history in order to disrupt autonomous grassroots urban history formation. Third, and lastly, said historiographical struggle manifests itself in how we represent the pasts of Indigenous peoples in the cities of the Americas. I make this argument through a critical reading of Nona Fernández’s representation of the Indigenous past of Santiago de Chile in her 2002 novel Mapocho.

Opera in the Tropics: Music and Theater in Early Modern Brazil, by Rogério Budasz; The Sweet Penance of Music: Musical Life in Colonial Santiago de Chile, by Alejandro Vera; Cinesonidos: Film Music and National Identity during Mexico’s “época de oro,” by Jacqueline Avila; Aaron Copland in Latin America: Music and Cultural Politics, by Carol A. Hess; Elite Art Worlds: Philanthropy,

<i>Opera in the Tropics: Music and Theater in Early Modern Brazil</i>, by Rogério Budasz; <i>The Sweet Penance of Music: Musical Life in Colonial Santiago de Chile</i>, by Alejandro Vera; <i>Cinesonidos: Film Music and National Identity during Mexico’s “época de oro,”</i> by Jacqueline Avila; <i>Aaron Copland in Latin America: Music and Cultural Politics</i>, by Carol A. Hess; <i>Elite Art Worlds: Philanthropy,

Investification in the housing market: exploratory study in Santiago de Chile

This study uses a quantitative methodological approach with geographically weighted regressions to address the phenomenon of investification in the Greater Santiago rental market. Using the collection and analysis of transaction data and urban indicators, the location patterns of residential investments are explored for specific urban functions at the census tract level. The analysis reveals that proximity to higher education institutions, stability in rental prices, and the presence of older adults are determining factors in the selection of investment properties. These findings evidence the transformation of the urban landscape as rental spaces for capital and highlight the growing socio-spatial segmentation, thus underlining the need for regulations that address the implications of investification in the urban dynamics of Greater Santiago.

Advancing Oro-Dental and Cranio-Maxillo-Facial Interventions for QoL: Injectable Hydrogel and BioCeramic NanoDelivery Platforms

In the ever-evolving landscape of healthcare, where science, technology, and clinical practice converge, the realm of cranio-maxillo-facial and oro-dental interventions stands at the forefront of transformative possibilities. This communication embarks on an illuminating journey into the heart of this dynamic field, where innovation knows no bounds. Collaborative student engagement has been instrumental in not only exploring but also bridging the chasm between diverse scientific disciplines and the practical intricacies of clinical application. Recent strides in drug delivery mechanisms, characterized by the ingenious fusion of cells and nano-carriers, have laid the foundation for a revolution in regenerative medicine. These breakthroughs promise a future where treatments are not only precise but also meticulously controlled, enhancing patient quality of life through the amelioration of disease conditions and restoration of bodily functions. Injectable hydrogels, another trailblazing innovation, have emerged as a beacon of hope. They offer versatile solutions that promise to redefine surgical and clinical practices by affording healthcare professionals spatio-temporal control, tunability, and stimuli-responsiveness. These hydrogels unlock the potential for the targeted delivery of therapeutic agents, including cells, genes, proteins, and drugs, revolutionizing tissue engineering, regenerative medicine, and aesthetic surgical interventions. BioCeramics, a burgeoning field, is redefining conventional wisdom in bone grafting and implant technology. These biomaterials are poised to usher in a new era of innovative approaches that enhance the mechanical and biological compatibility of implants, facilitating improved clinical outcomes and patient quality of life. Moreover, this communication serves as a herald of exciting news: the inauguration of a Doctoral (PhD) Program in Dental Sciences at the prestigious Universidad de los Andes in Santiago de Chile. This program beckons forward-thinkers, visionaries, and emerging scholars to partake in pioneering research at the Laboratorio de Biomateriales, Farmace uticos y Bioingenierí a de Tejidos Cra neo Ma xilo-Facial. As we embrace the future, limitless possibilities abound in this transformative health field, where advancing science and technology merge seamlessly to enhance the clinical and surgical armamentarium available for contemporary practices and users. This journey represents not only a dedication to scientific exploration yet an unwavering commitment to improving patient quality of life (QoL) and well-being thru the amalgamation of cutting-edge research, innovation, and compassionate care.

Bus fare evasion of the Santiago de Chile transportation system from a stakeholders perspective

This research presents a paradigmatic case study of fare evasion in the Chilean public transport system. It identifies the perceptions of different stakeholders who interact within this system, raising a series of discourses around the social legitimacy of evasion, a conduct traditionally punished and considered wrong. The methodology consists of the use of 41 semi-structured interviews of public transport system stakeholders, such as users, operators, political authorities, social groups, policemen, and others. A qualitative analyses organizes the data into three dimensions: i) context in which evasion takes place, distinguishing between the historic context, the social context, and the moral context; ii) legitimacy of payment, raising the main arguments from which to defend payment as rightful conduct; and iii) legitimacy of evasion, identifying the perceptions that justify evasion as an acceptable social conduct. The conclusions state evasion is a symptom of a much deeper problem. Socioeconomic inequality in Chile allows us to understand the role of public transport as a social right that grants social inclusion, facilitating equal access to the opportunities society offers.

The Ethics of Self‐Care: Risk, Responsibility, and Reproduction in Chile

AbstractThe meanings of self‐care are complex, ranging from radical political warfare to structural biopolitical governmentality. This paper explores lived tensions of self‐care by analysing women's experiences negotiating pregnancy in Santiago de Chile. Drawing on 40 life story interviews, the findings show that although sexual education, contraception, and abortion remain constrained and structured according to class inequalities, women are expected to care for themselves by managing the risk of pregnancy and assuming responsibility for their reproductive outcomes. I argue that politics of reproduction in Santiago de Chile are shaped by a neoliberal ethics of self‐care that outlines women as autonomous, rational, and self‐regulating agents while neglecting structural constraints that affect whether and when to have children. This neoliberal ethics of self‐care reinforces the overburdening of the self, the feminisation of reproduction, the privatisation of care, and the institutionalisation of carelessness, undermining the subversive and emancipatory potential involved in caring for oneself.

Planning for accessibility: the divide between research and policy in the promotion of equitable mobility

ABSTRACT Mobility-related social inequalities are receiving increasing attention from planning research and practice. Nevertheless, research seems to have a limited impact on urban policies addressing mobility. Using Santiago de Chile as a case study, the paper discusses the existing gaps between research on mobility-related equity concerns and existing policies and plans addressing urban mobility operating at national, metropolitan and municipal scales. An equity-based comparison is performed for different spatial planning instruments, exploring guiding concepts and deriving proposals through content analysis. The findings show that there is a comprehensive and multidisciplinary body of literature in Santiago on mobility and equity, approaching several dimensions of mobility, accessibility and social exclusion in relation to different population groups. However, the series of discourses, norms and actions (policies and programmes) operating at different planning scales lack coherence and address only some of the dimensions identified in the literature. Current plans and policies in Santiago have a limited scope and are difficult to modify, questioning their effectiveness for understanding and tackling mobility-related equity concerns.

Self-Organizing Topological Multilayer Perceptron: A Hybrid Method to Improve the Forecasting of Extreme Pollution Values

Forecasting air pollutant levels is essential in regulatory plans focused on controlling and mitigating air pollutants, such as particulate matter. Focusing the forecast on air pollution peaks is challenging and complex since the pollutant time series behavior is not regular and is affected by several environmental and urban factors. In this study, we propose a new hybrid method based on artificial neural networks to forecast daily extreme events of PM2.5 pollution concentration. The hybrid method combines self-organizing maps to identify temporal patterns of excessive daily pollution found at different monitoring stations, with a set of multilayer perceptron to forecast extreme values of PM2.5 for each cluster. The proposed model was applied to analyze five-year pollution data obtained from nine weather stations in the metropolitan area of Santiago, Chile. Simulation results show that the hybrid method improves performance metrics when forecasting daily extreme values of PM2.5.

A tool for universal accessibility assessment in the interior of dwellings

The present study proposes a tool for assessing universal accessibility in the interior of apartments, presenting a novel quantitative model for assessing the accessibility of buildings for buyers or tenants. For this, a multicriteria analysis for aggregating the assessment indicators with different units and scales is employed using a unique grade of accessibility according to four main pillars: Autonomy, Mobility, Comfort, and Safety. The assessment method has been applied in 35 show apartments in the urban area of Santiago in Chile. This work shows the application and results of 4 departments. The evaluation results are presented visually with a circular bar plot and a final grade in letter format from F to A. In general, it is observed that the four apartments proposed have a low degree of accessibility (letters F to D). And, the Autonomy pillar is clearly the lowest pillar in the selected apartments.

Assessment of noise pollution of fireworks during Christmas and New Year in the city of Buenos Aires: comparison with a different management strategy applied to the city of Santiago de Chile

Fireworks are widely celebrated worldwide but have raised environmental concerns due to pollutant emissions. This has prompted evolving legislation in many countries, necessitating scientific evidence for policy development. Existing literature mainly focuses on characterizing individual fireworks and quantifying noise variations between festive and non-festive periods. However, no such studies have been conducted in Argentina. This study aims to characterize noise levels generated by fireworks during the 2020 Christmas and New Year celebrations in Buenos Aires. Nine measurement systems were used, obtaining acoustic descriptors reflecting noise levels during these events. Results were compared with typical ambient noise levels in the city and those during the New Year's fireworks display in Santiago de Chile, where public access to individual fireworks is restricted. Findings indicate significant noise level increases during the Christmas and New Year celebrations, supported by the L01 percentile acoustic parameter, more effective in characterizing impulsive events than Equivalent continuous sound pressure level LeqA. Comparing results with Santiago de Chile, noise values in Argentina remained similar within a 1.1 km proximity to the fireworks show, whereas beyond that distance, Chilean residents experienced lower noise levels.

Associations Between Muscle Mass Levels and Functional Aspects in Non-Institutionalized Older Adults from Santiago, Chile

To determine the relationship between the apendicular skeletal muscle mass and functional levels in non-institutionalized older adults in Santiago de Chile. This is a quantitative, non-experimental, descriptive correlational, cross-sectional study of 59 older adults (13 men and 46 women) who live in the community, particularly in Santiago, Chile. The muscle mass was estimated through anthropometric values and a predictive, validated equation for calculating Skeletal Appendicular Muscle Mass (MMAE). Functionality was evaluated through the Functional Assessment of the Elderly (EFAM) instrument, used by the Ministry of Health of Chile since 1999. The comparison of means of the MMAE values was higher in men (13.73 vs. 20.74; α: 0.05). This difference was also observed in its minimum, maximum, and variability. In the sample, A higher percentage of subjects were at risk of dependency or self-reliant without risk. Both sexes behave similarly; however, proportionally, women are more self-reliant without risk. A chi-square test showed no dependency relationship between functionality and sex (α: 0.05). A similar result was obtained regarding the MMAE and Functionality relationship (α: 0.05). In the present sample, there was no significant direct linear correlation between the amount of MMAE and Functionality.

Students’ Perceptions of acoustic comfort in traditional and flexible learning environments: a study in Chile

The acoustic quality of educational spaces has an important impact on well-being and occupant performance. This study investigates noise perception and hearing ability among primary students in traditional learning environments (TLE) and flexible learning environments (FLE). A survey was conducted in Santiago de Chile, involving 21 teachers and 315 children from 13 schools, to gather responses on acoustic comfort. Additionally, a checklist was used to inspect the physical spaces. The analysis of students’ responses revealed that self-reported complaints related to indoor environmental quality (IEQ) predominantly focused on noise discomfort in both types of learning environments. A significant relationship was found between the type of space and children’s perception of noise from their peers. Although students in TLE reported greater annoyance with noise, those in FLE experienced slightly more listening problems. Interestingly, in FLE, students with an occupancy density greater than 2.1 m2 per student did not feel bothered by the noise produced by their classmates speaking. Although further research is needed, these findings highlight the crucial role of acoustic conditions in ensuring the comfort and hearing abilities of young students. Adequate acoustic treatment and enough space per student are important to mitigate potential indoor noise issues.

Effect of environmental conditions on the performance of a low-cost atmospheric particulate matter sensor

Continuous measurements of PM10, PM2.5, and PM1 concentrations were carried out by collocating a GRIMM Aerosol Laser Spectrometer model 11-C as a reference instrument and three Plantower PMS7003 low-cost sensor (LCS) from June 11, 2019, to April 23, 2020, in a residential/commercial area of the city of Santiago de Chile. Completeness, precision, linearity, bias, and error metrics were analyzed to evaluate the performance of PMS7003. Linear regression and quadratic polynomial models were proposed to correct the concentrations provided by LCS based on the environmental variables studied. The performance of the LCS was outstanding for the PM1 fraction, obtaining R2 = 0.98, slope = 1.1. PM2.5 and PM10 concentrations were underestimated in drier and warmer summer conditions and slightly overestimated in colder and wetter winter conditions. In the case of PM2.5, three correction models were proposed, two of which considered four possible conditions based on the relative humidity and temperature to identify their influence on the LCS performance, achieving R2 values of 0.869 and 0.875, respectively. The LCS showed low linearity and bias value for PM10; the correction model for this PM fraction with the highest value in the metrics obtained an R2 = 0.630, therefore its use is recommended only for educational purposes.

Baseline Corticosterone, Stress Responses, and Leukocyte Profiles in Chicks of Precocial Birds in Rural and Urban Environments.

The urban environment produces complex relationship among urban stressors that could change the levels of the steroid hormone, glucocorticoid (GCs). Studies that have evaluated baseline corticosterone (Cort) levels (the main GC in birds) and stress responses during development in urban and rural environments have obtained contrasting results. This ambiguity could partially be because the studies were carried out in altricial species, where parental care and sibling competition can affect Cort levels. Therefore, in this study, we compared levels of circulating baseline levels of CORT (blood sample obtained within 3 min of capture) and stress responses (blood sample obtained 30 min after capture) and the H/L ratio (an alternative method to measure stress) in chicks of a precocial bird, southern lapwings (Vanellus chilensis), from one rural (6 chicks), one urban low-polluted (13 chicks), and one urban high-polluted (10 chicks) site of Metropolitan Region of Santiago de Chile. We observed higher baseline Cort (2.41 ± 1.78 ng/mL) in the urban high-polluted site, a higher H/L ratio (0.51 ± 0.20) in the urban low-polluted site, and similar stress response across the three sites. We propose that the difference in stress physiology we observed within Santiago de Chile is because the two zones are at extremes in terms of stressors (noise, light, chemical, and human presence). It is unusual to find a precocious bird that lives in both urban and rural areas; therefore, the results of this study will advance our knowledge of the effect of the urban environment during the development of wildlife, which is relevant in terms of management and conservation.

Experimental and numerical study of desalination using solar energy and phase change materials

The present work experimentally desalinate water and model a passive solar desalinator of 0.55 m2 that uses phase change materials (PCM), assessing the effects of storing energy in 4.5 kg of coconut oil or paraffin wax contained in copper tubes, and the mass of water in the container (5.55, 8.25 and 11.0 kg), on the unit performance. The experiments carried out in Santiago de Chile allowed to obtain condensate masses between 3.2 and 4.3 kg/m2 per batch with a temperatures between 23 and 83∘C for the absorber plate and 21–77∘C for the glass. Annual water production ranged from 1120 to 1313 liter/m2, with costs between 0.0165 and 0.0593 $/liter. PCM incorporation had no impact on production as the exposed area is shared between absorber plate and tubes. To better evaluate the effect of the parameters studied, results are presented as the ratio between the mass of condensate and the solar energy received, which gives independence from the solar irradiation variability and allowed to identify a slight superiority in the productivity of condensate using coconut oil. The model developed and coded in MATLAB, including PCM and the effect of self-shading, adequately predicts the mass of condensate and phase temperatures (water, glass and PCM) with a mean root mean square error of 0.03 kg and 1.9∘C respectively. The model is characterized by a low computation time and a high level of prediction for the condensate mass.

Understanding cyclists’ conflicts in the streets of a Latin American metropolis

Promoted by most governments as a sustainable form of transportation, cycling is surging worldwide. Despite the positive impacts of cycling, conflicts between cyclists and other street users such as pedestrians, cars and buses have increased, especially in countries lacking proper cycling infrastructure. This paper aims to understand a series of conflicts experienced by cyclists in Santiago de Chile, where cycling has expanded rapidly in the last fifteen years. To do so, three focus groups were held with cyclists having different levels of experience. The participants were asked to describe the main conflicts with other modes of transport and road users, as well as the coping strategies employed to deal with these conflicts. An inductive analysis ended with four categories related to cyclists’ conflicts in the streets and two related to strategies and lessons dealing with motorised vehicle drivers and other cyclists.The analysis indicates that the unequal distribution of road space negatively influences cyclists’ experiences, who perceive themselves as being threatened constantly by overtaking cars in close proximity, as well as by different forms of verbal and sometimes physical aggression. It indicates that cyclists develop strategies to mitigate conflicts, ranging from making themselves visible at all times, to making use of bodily gestures. However, conflicts can still escalate. The results suggest that, in auto-centric urban contexts, cycling is a challenging chore that happens surrounded by the sensation of having fragile entitlements.

Perceptions of teachers and students about the use of ICTs in physical education classes: uses, advantages, and projections

The digitalization of societies is not a homogeneous or mechanistic process that moves in parallel to technological processes, since the uses of ICT are linked to the social and political contingency of each country. Consequently, this paper set out to analyze the perception of teachers and students about the use of ICTs in Physical Education classes in schools in Santiago of Chile. The use of ICTs in Physical Education is uncommon in Chile, these are focused on physical exercise and folklore teaching. A qualitative methodology was used. Based on structured interviews with teachers and students from schools in the southern area of Santiago. These were analyzed through Atlasti software. A qualitative analysis of content and a thematic analysis was carried out through data coding. The results show that there are differences in the perception of ICT by teachers and students. The former prioritize technologies applied to physical exercise. The latter consider that technologies are important for obtaining information and managing communication between teacher and student. It is concluded that it is necessary to generate institutional mechanisms that allow socialization in new skills and knowledge of technologies, since the lack of training in these skills could produce severe problems in the integration into the new digital society that is developing in Chile. Likewise, there is a generational gap in the use of this type of technologies, which would affect the older population. Keywords: ICTs in the classroom; Physical education; Digital society; Education in Chile.