Universidad San Francisco de Quito

Roux-en-Y gastric bypass (RYGB) is one of the most performed bariatric procedures worldwide. Although the complication rate is low, the benefits gained from surgery outweigh many risks, including malnutrition, electrolyte imbalances, and recurrent marginal ulcers. Since RYGB changes the length of the functioning small bowel and because small bowel length is highly variable, the outcomes, which include weight loss, resolution of medical problems, and development of nutritional deficiencies or limb length, can be highly variable. We present a case of laparoscopic reversal of RYGB. A 52-year-old female patient presented with diarrhea, electrolyte imbalance, and severe weight loss 12 months after RYGB, and a reversal of RYGB was needed to overcome these severe issues. After surgery, she made a full recovery. On follow-ups, she is doing well.

This chapter is focused on hydrogen, its production methods, and how this energy vector fits into multi-energy systems (MES) when integrated with other renewable energy sources. Hydrogen will play a fundamental role in the integration of renewable energy. It will become the second energy vector that, together with electricity, will allow the integration of sustainable energy systems. Today, water electrolysis is the main method used to produce hydrogen; the widespread adoption of water electrolysis is due to the need to reduce energy consumption, cost, and maintenance and improve reliability, durability, and safety. In addition, the creation of a hydrogen energy storage system is an important milestone in the achievement of completely renewable energy systems, while guaranteeing the dependability and stability of power systems. Automatic control applied to alkaline electrolyzers is fundamental for hydrogen production, as strategies to handle internal processes of complex electrolysis-based devices are strongly needed to guarantee proper hydrogen production with specific degrees of purity.

Aposematic animals use conspicuous warning signals to advertise their chemical defences to predators. Selection by predators can favour conspicuousness and large pattern elements, which enhance predator avoidance learning. In aposematic species, conspicuousness often varies among individuals. This variation can be explained if conspicuousness reflects the levels of chemical defences, if signal production or defence acquisition is costly, and if physiological trade-offs and opposing selection pressures impose constraints. To understand the link between conspicuousness and chemical defences, we need to quantify the variability in warning signals and identify the chemical compounds involved. Here, we examined the warning signal variability and chemical composition of the red-necked wasp moth (Amata nigriceps). We photographed the wings and abdomens of male and female moths and analysed their chemical composition using ultra-performance liquid chromatography. Females displayed more orange on their wings, a trait known to enhance protection against predators. While we ruled out the presence of pyrrolizidine alkaloids in adult moths, an untargeted metabolomics approach suggests that they sequester other compounds, such as steroidal alkaloids and alkylbenzenes, which may serve as chemical defences. Females had higher concentrations of these compounds than males but ecotoxicology assays with Daphnia showed that male and female moths exhibited similar levels of toxicity.

We assessed combined, low-cost physical–chemical and biological treatment system for the remediation of acid rock drainage (ARD). Two columns composed of native soil amended with zero valent iron and iron sulfide (ZVI/FeS) nanoparticles-based Technosols were connected to a sulfate-reducing (SR) bioreactor; this integrated treatment system was fed with ARD obtained from mines in El Oro, Ecuador. A control sulfate-reducing bioreactor fed directly with ARD was run in parallel. The bioreactors were operated dynamically for four periods, and every 21 days, the fraction of ARD in the influent was increased stepwise from 25 to 100%. The integrated treatment system demonstrated superior removal efficiencies for Fe (99%), As (99.9%), Cd (99%), Cu (98%), Mn (91%), and Zn (99.9%), while both bioreactors achieved similar sulfate reduction (50–52%) and raised ARD pH from 2.75 to ~ 8. However, the ZVI/FeS nanoparticles-based Technosols significantly improved the removal of As (99.9% vs. 68%) and Mn (91% vs. 71%), compared to the control bioreactor. Molecular ecology analysis of the biomass in the bioreactors using 16S rRNA sequencing revealed that higher ARD concentrations enhanced sulfidogenesis, promoting beneficial interactions within communities in the sulfate-reducing niche. This study highlights the value of the ZVI/FeS nanoparticles-based Technosols in optimizing ARD bioremediation, offering a promising solution for mining effluent management in low-middle-income countries (LMIC). Graphical Abstract Performance of an integrated system composed of native soil amended with ZVI/FeS nanoparticles-based Technosols and a bioreactor for the treatment of acid rock drainage. Created in BioRender.com 02/10/2024

Temperature and nutrient availability are critical for the growth and development of aquatic invertebrates. However, an increase in these factors, derived from human stressors, could impact their food resources, such as periphyton, and subsequently affect larval metabolism and growth. We investigated the combined effects of rising temperature and nutrient enrichment (N and P) on periphyton biomass and a subtropical mayfly nymph species, Thraulodes consortis, during a 15-day microcosm experiment in Northwest Argentina. Our findings revealed a positive synergistic effect on chlorophyll-a concentration with temperature increases of + 2.5 °C and + 5 °C when combined with nutrient enrichment (+ P or + N). Mayfly nymphs showed reduced survival rates in the + 5 °C scenario with low oxygen levels, and survival rates displayed an additive response in all multiple stressor scenarios. Furthermore, the head capsule width of the nymphs significantly increased at all three temperature scenarios over the 15-day experiment, particularly in the presence of increasing nutrient levels. This suggested a strong metabolic response to these multiple stressor scenarios. This study emphasizes the diverse impacts of temperature and nutrient enrichment (N and P) on primary productivity, which could potentially alter the water chemistry of a subtropical river and affect the metabolism of primary consumers.

Objectives The 12-item Self-Compassion Scale–Short Form (SCS–SF) is a widely used instrument for the assessment of self-compassion. To date, there have been few examinations of this instrument’s psychometric properties, particularly across nations and languages. Therefore, we used data from the Body Image in Nature Survey (BINS) to assess measurement invariance of the SCS–SF across nations, languages, gender identities, and age groups. Methods Participants (N = 56,968) from 65 nations completed the SCS–SF in 40 languages. Using these data, we tested various hypothesised models of the SCS–SF in the total sample and, using multi-group confirmatory factor analysis, tested for invariance of the optimal model across national groups, languages, gender identities, and age groups. Results In the total dataset, we found that an 11-item, 2-factor model (i.e., SCS-11) provided best fit to the data, with the two factors tapping distinct constructs of compassionate and uncompassionate self-responding. The SCS-11 was found to be partially scalar invariant across national groups and languages, and fully scalar invariant across gender identities and age groups. There was wide variation in latent means for the two factors, particularly across national groups and languages. Further analyses showed negligible associations between the two factors and sociodemographic variables, including marital status, financial security, and urbanicity. Conclusions Our results suggest that it may be possible to derive a stable 2-factor model of the SCS–SF for use in cross-cultural research, but also highlight the likelihood of cross-national and cross-linguistic variations in the way that self-compassion is understood.

Inland waters emit large amounts of carbon and are key players in the global carbon budget. Particularly high rates of carbon emissions have been reported in streams draining mountains, tropical regions, and peatlands. However, few studies have examined the spatial variability of CO2 concentrations and fluxes occurring within these systems, particularly as a function of catchment morphology. Here we evaluated spatial patterns of CO2 in three tropical, headwater catchments in relation to the river network and stream geomorphology. We measured dissolved carbon dioxide (pCO2), aquatic CO2 emissions, discharge, and stream depth and width at high spatial resolutions along multiple stream reaches. Confirming previous studies, we found that tropical headwater streams are an important source of CO2 to the atmosphere. More notably, we found marked, predictable spatial organization in aquatic carbon fluxes as a function of landscape position. For example, pCO2 was consistently high (>10,000 ppm) at locations close to groundwater sources and just downstream of hydrologically connected wetlands, but consistently low (<1,000 ppm) in high gradient locations or river segments with larger drainage areas. Taken together, our findings suggest that catchment area and stream slope are important drivers of pCO2 and gas transfer velocity (k) in mountainous streams, and as such they should be considered in catchment‐scale assessments of CO2 emissions. Furthermore, our work suggests that accurate estimation of CO2 emissions requires understanding of dynamics across the entire stream network, from the smallest seeps to larger streams.

Background: Taenia solium is a zoonotic parasite causing significant health and economic burdens, with complex transmission dynamics requiring improved control strategies. Methods: This study investigates the effect of T. solium infection and reinfection on cyst development in pigs and evaluates how acquired immunity constrains parasite burden. A total of 116 pigs were purchased from commercial farms in northern Peru and housed in pathogen-free facilities under controlled conditions. Of these, 110 pigs were allocated to 18 experimental groups to (1) evaluate the impact of infection and reinfection with varying doses of T. solium eggs and (2) generate a model to predict the number of live cysts produced, given the dose and age at infection. Gravid proglottids collected from human cases of T. solium taeniasis were used to prepare egg pools, ensuring viability consistency. Infections were administered orally using gelatin capsules via esophageal catheterization, followed by necropsy 10 weeks after the final infection event to quantify cysts. A negative binomial regression model was used to analyze cyst burden dependence on infection dose, past infection, age, and other factors. Results: No statistically significant differences in cyst counts were observed between pigs infected once and those that were reinfected, regardless of the initial dose (as low as 100 eggs) or reinfection dose (up to 20,000 eggs). This finding highlights that infection results in strong acquired immunity, effectively blocking subsequent infections. A quantitative dose-response model suggests that the relationship between egg dose and the number of viable cysts is best described by a power relationship. Combining data from single-infection and reinfected pigs into a unified model improved prediction precision. Finally, incorporating age at infection results in a model of the number of viable cysts in pigs depending on dose and age that combines acquired and innate immunity effects, i.e. changes in susceptibility with age. Conclusions: Initial exposure to T. solium eggs induces strong acquired immunity in pigs, effectively preventing reinfection. Our quantitative dose-response model predicting live cyst counts based on egg dose and pig age offers valuable insights for integrating immunity processes into models of T. solium transmission.

Density functional theory calculations were applied to elucidate the co-adsorption mechanism of different nanoplastic-neonicotinoid insecticides (NP-NEO) complexes where polyethylene terephthalate (PET), polyethylene (PE), and polystyrene (PS) are tested as adsorbents, and imidacloprid (IMI) and clothianidin (CLO) are considered adsorbates. HOMO energies indicate all nanoplastics (NPs) tend to donate electrons, while LUMO analysis shows PET and CLO favor electron acceptance, while PE, PS, and IMI are unstable, the last one due to resonance effects. Complex formation slightly increases HOMO energies but maintains trends, while LUMO energies improve only in PET due to its carbonyl groups. The LUMO–HOMO gap (GLH) decreases significantly in PE-IMI and PE-CLO (~ 28%), reducing stability. Our results reveal that electrostatic and dispersion interactions dominate adsorption, contributing ~ 90% to the stabilization of NP-NEO complexes through physisorption onto the surface of all plastic matrices. Adsorption energies span the range from − 18.32 to − 32.56 kcal/mol, with the PE-IMI complex being the most stable. Our results provide molecular-level insights into the nature of pesticide-nanoplastic interactions, contributing to a better understanding of how these materials may influence the environmental fate of neonicotinoids. Calculations of density functional theory at the wB97XD/def2-SVP level of theory in Gaussian16 were implemented. PCM, BSSE, and dispersion effects were considered. To gain insights into the nature of the interaction, ALMO-EDA and IGMH analyses were performed. Finally, the structures were visualized in the VMD program.

Leptospirosis (caused by pathogenic bacteria in the genus Leptospira ) is prevalent worldwide but more common in tropical and subtropical regions. Transmission can occur following direct exposure to infected urine from reservoir hosts, or a urine-contaminated environment, which then can serve as an infection source for additional rats and other mammals, including humans. The brown rat, Rattus norvegicus , is an important reservoir of Leptospira spp. in urban settings. We investigated the presence of Leptospira spp. among brown rats in Boston, Massachusetts and hypothesized that rat population dynamics in this urban setting influence the transportation, persistence, and diversity of Leptospira spp. We analyzed DNA from 328 rat kidney samples collected from 17 sites in Boston over a seven-year period (2016–2022); 59 rats representing 12 of 17 sites were positive for Leptospira spp. We used 21 neutral microsatellite loci to genotype 311 rats and utilized the resulting data to investigate genetic connectivity among sampling sites. We generated whole genome sequences for 28 Leptospira spp. isolates obtained from frozen and fresh tissue from some of the 59 positive rat kidneys. When isolates were not obtained, we attempted genomic DNA capture and enrichment, which yielded 14 additional Leptospira spp. genomes from rats. We also generated an enriched Leptospira spp. genome from a 2018 human case in Boston. We found evidence of high genetic structure among rat populations that is likely influenced by major roads and/or other dispersal barriers, resulting in distinct rat population groups within the city; at certain sites these groups persisted for multiple years. We identified multiple distinct phylogenetic clades of L. interrogans among rats that were tightly linked to distinct rat populations. This pattern suggests L. interrogans persists in local rat populations and its transportation is influenced by rat population dynamics. Finally, our genomic analyses of the Leptospira spp. detected in the 2018 human leptospirosis case in Boston suggests a link to rats as the source. These findings will be useful for guiding rat control and human leptospirosis mitigation efforts in this and other similar urban settings.

Immunity to severe malaria is acquired quickly, operates independently of pathogen load, and represents a highly effective form of disease tolerance. The mechanism that underpins tolerance remains unknown. We used a human rechallenge model of falciparum malaria in which healthy adult volunteers were infected three times over a 12 mo period to track the development of disease tolerance in real-time. We found that parasitemia triggered a hardwired innate immune response that led to systemic inflammation, pyrexia, and hallmark symptoms of clinical malaria across the first three infections of life. In contrast, a single infection was sufficient to reprogram T cell activation and reduce the number and diversity of effector cells upon rechallenge. Crucially, this did not silence stem-like memory cells but instead prevented the generation of cytotoxic effectors associated with autoinflammatory disease. Tolerized hosts were thus able to prevent collateral tissue damage in the absence of antiparasite immunity.

The choice of where to breed can have fundamental consequences for offspring development and survival. Among amphibians, desiccation is one of the biggest threats to offspring survival, especially in species that deposit their clutches in terrestrial habitats. In several species, hydration of the clutch is ensured by a caregiving parent, but in species without prolonged care, site selection becomes critically important for securing constant external sources of hydration. We used the Spiny Cochran frog (Teratohyla spinosa), a Neotropical glassfrog in which females perform only short-term brooding to clutches, but then both parents leave the offspring, to test the effect of oviposition site selection within leaves on offspring development and survival. Previous observations have revealed that this species preferentially deposits eggs on the underside of leaves close to their margins. We hypothesized that T. spinosa strategically chooses this position to ensure clutch hydration during embryonic development, as water drops will slide from the edges to the tip of the leaves before dripping. To this end, we performed a clutch translocation experiment where we manipulated the location of clutches by placing them away from the leaf margin and compared their level of hydration, hatching time, and mortality rate to clutches that were kept on the leaf margins. Contrary to our expectations, we found that clutch hydration and mortality were not affected by the location on the leaf. These findings suggest that the observed clutch deposition on the edges of leaves in this species is not enhancing hydration conditions – at least under high humidity conditions.

Objective This study aims to evaluate the microbial load in the Saguambi, Mindo, and Canchupí Rivers in Mindo (Ecuador) by quantifying bacteriological indicators (Escherichia coli and total coliforms) and identifying pathogenic microorganisms (e.g., Giardia, Cryptosporidium spp., Helicobacter pylori, Mycobacterium tuberculosis, and Mycobacterium leprae) using molecular techniques. This assessment aims to establish the potential risk associated with the consumption and recreational use of these water sources. Results A total of 36 surface water samples were analyzed in this study, with 12 samples collected per river (Saguambi, Mindo, and Canchupí). Sampling was conducted in duplicate at two collection points per river (before and after the community) across three seasons (dry, rainy, and transitional), resulting in 4 samples per river per season. All samples showed consistently high microbial levels exceeding international guidelines at most collection points across the three rivers. The Canchupí River exhibited the highest E. coli and total coliform counts during the dry season, with values of 1.50 × 10⁷ and 1.79 × 10⁷ CFU/100 mL, respectively. The Saguambi River showed the highest E. coli levels in the transitional season (9.42 × 10⁴ CFU/100 mL). The Mindo River peaked in E. coli (7.15 × 10⁵ CFU/100 mL) and total coliforms (5.85 × 10⁵ CFU/100 mL) after the community. Molecular analysis identified M. tuberculosis in all rivers year-round. M. leprae was found in the Saguambi and Mindo Rivers, and H. pylori was identified in both Mindo and Canchupí Rivers. Giardia and Cryptosporidium parasites’ detection varied among rivers and seasons.

Latin American countries have faced limited access to new scientific technologies for many years due to restricted budgets for research programs, which has hindered local scientific development. These research disparities became especially evident during the COVID-19 pandemic, as lower-middle-income countries (LMICs) like Ecuador and Nicaragua had restricted access to genomic surveillance protocols, sequencing technologies, and adequate infrastructure, compromising global pandemic preparedness and response. In response to the urgent need for SARS-CoV-2 research capabilities in these countries, the Asian-American Center for Arbovirus Research and Enhanced Surveillance led the initiative, collaborating with the NGO Sustainable Sciences Institute and LMIC stakeholders, including universities and Ministries of Health, to develop pandemic-related research programs, provide resources, and conduct peer training workshops for local health scientists. Over the past five years, collaborative efforts have enabled teams in Ecuador and Nicaragua to establish sustainable research capacity and technology-sharing initiatives, as showcased by the institutionalization of government-led genomic surveillance efforts. This has opened new research opportunities in genomic surveillance for other emerging and reemerging pathogens and strengthening South-South collaboration.

Background Better understanding the impact of dietetic services on nutrition practices seems required as it may represent an opportunity for optimization in post–cardiac surgery patients. The present study aims to evaluate and compare nutrition practices and clinical outcomes in post–cardiac surgery intensive care unit (ICU) patients with and without dietetic services. Methods This is a secondary analysis of a multinational prospective observational study in patients ( n = 237) with >72 h of post–cardiac surgical ICU stay with and without dietetic services describing nutrition practices and outcomes up to 12 days after ICU admission. Results Dietetic services were available in 61.5% (8 of 13) ICUs (1.0 ± 0.5 full‐time equivalents/10 beds). Enteral nutrition was initiated <48 h from ICU admission in 49.6% and 59.1% of patients at sites with vs without dietetic services, respectively. Parenteral nutrition was started within 118.3 ± 56.5 and 131.5 ± 69.2 h at sites with vs without dietetic services, respectively. Energy target (23.7 ± 4.8 vs 24.6 ± 4.8 kcal/kg body weight/day) and actual supply (10.5 ± 6.7 vs 10.3 ± 6.2 kcal/kg body weight/day) did not differ between the groups. Protein targets (1.4 ± 0.4 vs 1.1 ± 1.3 g/kg body weight/day) and actual protein provision (0.6 ± 0.4 vs 0.4 ± 0.3 g/kg body weight/day) were higher in patients at sites with vs without dietetic services. Conclusion Improvements in medical nutrition therapy practices in patients after cardiac surgery are needed in ICUs with and without dietetic services. Appropriately staffed dietetic services as essential members of the medical care team may be crucial to transfer knowledge on adequate medical nutrition therapy strategies into practice.

Background Passive acoustic telemetry is a method used to quantify residency within an array of receivers, but this technology has limitations for capturing complex behaviors in sharks: pulse delays and detection range drop-offs in near-shore habitats. This study addressed residency calculation methodologies by examining visitation qualifier functions (thresholds) in commonly used R packages. Methods Random walk models simulated the mismatch between detections on acoustic receivers and modeled shark movements, by testing 30-min, 1-h, 2-h and 24-h visit thresholds to compare gaps between shark detections at different transmitter settings (1- and 5-min delays). We also modeled tracks of transient sharks to show how these animals may interact with passive acoustic receivers differently than resident individuals. Results Our results suggested that longer transmitter (tag) pulse delays (1–5-min standard for sharks and larger fish) required short (< 30 min) visit thresholds, as they reduced variability in residency times. Consequently, using thresholds of less than 2 h increased the number of counted visits that stemmed from the same events. Similarly, the 5-min delay also predicted greater elapsed residency times than did the real path. Our directional walks sent transient sharks through a receiver at 0–1 and 1–2 m/s; under these scenarios, transmitters were unlikely to ping twice (default minimum visit qualifier) if 5-min pulse delays were set on their transmitters (16.4%), whereas 1-min delays did frequently (84.2%). This indicated that a 5-min delay may misrepresent residency time for transient sharks. Conclusions Thresholds and detection qualifiers manually set during passive acoustic surveys can bias residency and visitation results, and careful consideration should be applied on the basis of the life history (residential or transient) of the target species.

This chapter investigates the intricate dynamics of migration, gender and class within the burgeoning food truck scene in Quito, Ecuador. It captures the period of rapid growth during 2017–2018 and the subsequent decline influenced by the COVID-19 pandemic. The study explores how the cosmopolitan aesthetics of food truck culture intersect with urban branding, providing a platform for both local and migrant entrepreneurs, notably from Venezuela, to engage in the culinary economy. Despite the cosmopolitan veneer, the analysis reveals underlying class and cultural tensions that govern access and participation in this space. Through participant observations and interviews with food truck owners, workers and consumers, the research uncovers the nuanced ways in which social class, migration and gender roles play out in this unique urban setting. The findings illuminate the role of food trucks in shaping new urban spaces, reflecting broader socioeconomic transformations and the complexities of urban life in Quito.

In the present work, a new definition of the conceptual density functional theory reactivity indexes is proposed, based on a cubic interpolation of the energy as function of number of...

Salmonella is one of the most important foodborne pathogens worldwide. Therefore, this study was conducted to understand the importance of this microorganism in street food and the environment of an urban park in Quito, Ecuador. This research included phenotypic characterization and whole genome sequencing (WGS) analysis of isolates from different food matrices and fecal samples of dogs and pigeons. Salmonella was found in 10% (18/180) of the food samples, 3% (3/100) of the dog stool samples, and 5% (5/100) of the pigeon stool samples. These results also showed that meals containing any sauce or eggs were associated with a high probability of Salmonella isolation, regardless of other ingredients. All Salmonella isolates from food were identified as Salmonella enterica serovar Typhimurium (S. Typhimurium) while isolates from animal feces belonged to Salmonella enterica serovar Infantis (S. Infantis) and S. Typhimurium. WGS analysis showed that all S. Typhimurium strains belonged to ST19 and S. Infantis to ST32 according to the Multi-Locus Sequence Type (MLST) scheme. These strains were not related to Salmonella genomes of other origins when a Single Nucleotide Polymorphism (SNP) tree analysis was carried out. Antimicrobial resistance genes, such as blaCTX-M-65, were predominantly linked to the pESI-like plasmid found in S. Infantis. These results show the importance of urban fauna as a reservoir of S. Infantis and the impact these animals could have in terms of public health.