Repositorio Académico de la Universidad Católica del Maule
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Implementation of an experimental vertical flow treatment wetland for combined sewer overflow in the south of Chile
No full textThis work aims to evaluate the performance of Vertical flow (VF) treatment wetlands (TWs) operated in parallel and sequentially for the treatment of combined sewer overflow (CSO) in Chile during the first operative period. An experimental plant was operated at three outflow rates: 0.01 L/(s*m2), 0.03 L/(s*m2) and 0.05 L/(s*m2). Influent and effluent samples from VF TWs were taken every 24 h for a period of 72 h. The water quality parameters that were evaluated included pH, Electrical Conductivity (EC), turbidity (TU), total suspended solids (TSS), 5-day biological oxygen demand (BOD5), chemical oxygen demand (COD, total and dissolved), forms of nitrogen (NH4+-N, NO3−-N, TN), total phosphorus (TP), and E. coli. Reductions in pH value below 1.0 and no significant reductions (p > 0.05) on EC were observed in effluents. Furthermore, removals above 75 % for TSS, TU, BOD5, and CODt, were stable during the 4-day operational time and for the three outflow rates. In terms of nutrients, similar behavior was observed for the three outflow rates. NH4+-N was effectively removed, without complete transformation into NO3−-N, and TN removal was enhanced after 2-day of operation. TP removal was above 60 % and related to Ca-content in sand used in the wetland bed. Significantly improved results were achieved at 0.03 L/(s*m2). However, E. coli showed low removals of 1 log-unit across the three outflow rates, necessitating an effluent disinfection system. Hence, the system based on VF TWs with parallel operation and sequential feeding, is a promising technology for CSO treatment in the Chilean context
Antarctic endophytic fungi enhance strawberry resilience to drought and heat stress by modulating aquaporins and dehydrins
No full textGlobal climate change is linked to an increased occurrence of heat waves and droughts, which alter plant growth and development, and thus threaten food security. By associating with generalist root fungal endophytes that are adapted to harsh environments, crop plants can improve productivity under adverse conditions. Here, we examined the effects of two root endophytes isolated from Antarctica plants (Penicillium chrysogenum and P. brevicompactum) on mechanisms of tolerance to heat and drought in strawberry (Fragaria x ananassa). We found that inoculated plants exhibited better water retention, increased photosynthesis, reduced proline content and lipid peroxidation, and modulated antioxidative enzymatic activity. Transcriptomic and cis-element/transcription factor analyses revealed that differentially expressed genes (DEGs) were associated with abscisic acid (ABA) signaling, including dehydrins, as well as with cellular water homeostasis, such as aquaporins. These DEGs reveal mechanisms that enhance the physiological performance of endophyte-inoculated plants under drought and high-temperatures. This study highlights the novel role of Antarctic fungi in modulating ABA signaling and aquaporin expression, offering potential agricultural applications to enhance plant stress tolerance, which is crucial for improving food security
Reflection in educational interactions: analysis of scientific inquiry practices from the ALACT model
No full textEn la enseñanza de las ciencias, las interacciones educativas son cruciales para levantar concepciones alternativas y transitar hacia una ciudadanía responsable y alfabetizada. Sin embargo, los paradigmas científicos tradicionales limitan las formas con que el profesorado en ciencias intercambia significados sobre la realidad con sus estudiantes. Por ello, la reflexión docente en ciencias es una oportunidad para el desarrollo de prácticas de indagación acordes a las demandas educativas actuales. El presente estudio hermenéutico busca identificar y caracterizar elementos reflexivos que surgen de la visualización de las interacciones educativas por medio de actividades de indagación científica. A dos docentes se realizaron entrevistas de recuerdo estimulado a partir de videograbaciones de sus clases, cuyas transcripciones fueron analizadas a partir del modelo reflexivo ALACT. Los resultados indican que el profesorado reflexiona y moviliza sus prácticas repensando interacciones que involucran las visiones del mundo cotidiano, la tecnología, el diálogo, el trabajo colaborativo, el valor de las preguntas- respuestas, así como las iniciativas emergentes estudiantiles. La concreción de ciclos reflexivos da sentido y valor al ejercicio docente que, desde una perspectiva situada, comunicativa y epistemológica, llama a profundizar en estudios longitudinales futuros que capturen las trayectorias reflexivas del profesorado en el marco de su continuo desarrollo profesional
Generating transcriptomic resources in the teleost fish black cusk-eel (Genypterus maculatus) to evaluate thermal stress in the liver under a climate change scenario
No full textThe black cusk-eel (Genypterus maculatus) is a native fish that is relevant for traditional Chilean fisheries and has aquaculture potential. However, the genomic information and the biological knowledge related to the effect of thermal stress response are limited. This study generated the first de novo transcriptome assembly of the liver of G. maculatus and investigated the hepatic response to thermal stress in the G. maculatus. The de novo assembly resulted in 26,620 annotated transcripts, with an N50 of 2297, and a GC% of 49.76%. BUSCO analysis showed 97.1% and 75.7% complete orthologous (Metazoa and Actinopterygi, respectively). Functional annotation showed a total of 55,556 GO terms, with 26,128 annotations on biological process, 15,225 annotations on molecular functions, and 14,213 annotations on cellular component. The RNA-seq analysis revealed 94 differentially expressed transcripts in response to thermal stress, with 64 downregulated and 30 upregulated transcripts. The enrichment analysis showed biological processes related to double-strand break repair via homologous recombination, reciprocal meiotic recombination, and DNA repair. A significant increase in cortisol levels with no significant difference activity of hepatic enzymes (ALT, AST, AP) due to thermal stress was observed. Also, an increase in DNA damage (AP sites formation) and lipid peroxidation (HNE protein adducts) in the liver due to thermal stress was observed. The differentially expressed transcripts were validated using qPCR, confirming the RNA-seq results. The findings provide valuable genomic information for G. maculatus and highlight the physiological and molecular responses to thermal stress in the species under the context of climate change
A DNA-based investigation of endolithic community succession on shells of the limpet Patella depressa Pennant 1777
No full textBiotic and abiotic calcium carbonate structures are used as a substrate by bioeroding organisms, or euendoliths, worldwide. Euendoliths can have serious ecological effects on living hosts, and with global increases in ocean acidification and warming, the efficiency of erosion by marine euendoliths is likely to increase. Here, we used growth curve data for the limpet Patella depressa and 16S rRNA sequencing to explore succession in the endolithic community on the shells of P. depressa throughout its range across Great Britain. Limpet age correlated well with the extent of erosion within sites, but differed among sites, with those at the centre of the host range showing greater erosion when corrected for age. Alpha-diversity and richness of cyanobacteria decreased with the extent of erosion, particularly during the earlier stages of erosion. A decrease in the accumulation rate of Amplicon Sequence Variants (ASVs) occurred at around 80 % of cumulative ASVs, at a shell age of between 1.4 and 2.7 years. Cyanobacterial community composition differed among the shells from the different sites, but despite these differences, there were no discernable patterns in the abundance of specific taxa that were associated with limpet age or the extent of erosion. The results revealed that, when examined at a high taxonomic resolution, cyanobacterial community succession is more complex than previously thought, and may be site-specific. However, the trends observed indicate that cyanobacterial community succession occurs on calcifying organisms in vivo, with a shift towards a climax community after 1.4–2.7 years for P. depressa
Xbox Kinect Sports effects on cognition status and physical performance in physically inactive older females: a randomized controlled trial
No full textBackground/Objectives: This study aimed to compare the effects of Xbox Kinect Sports (XKS) relative to an inactive control group (CG) on cognitive status and physical performance in physically inactive older females. Methods: A randomized controlled trial study was conducted with the following groups: XKS (n = 15) and CG (n = 15), considering three weekly sessions of 60 min for 24 weeks. A two-way mixed analysis of variance with repeated measures was performed. Results: A two-way mixed ANOVA revealed significant time × group interactions for the Mini-Mental State Examination (MMSE) (F(2,18) = 14.8, p = 0.000, ηp2 = 0.292, large effect), Timed Up-and-Go (TUG) (F(2,18) = 19.5, p = 0.000, ηp2 = 0.351, large effect), and Falls Efficacy Scale-International (FES-I) (F(2,18) = 6.55, p = 0.015, ηp2 = 0.154, large effect). No significant interactions were observed for the Berg Balance Scale (BBS) (F(2,18) = 0.998, p = 0.324, ηp2 = 0.027, small effect), Maximal Isometric Handgrip Strength (MIHS) (dominant: F(2,18) = 0.163, p = 0.688, ηp2 = 0.005; non-dominant: F(2,18) = 0.012, p = 0.912, ηp2 = 0.000, small effects), or Maximal Isometric Pinch Strength (MIPS) (dominant: F(2,18) = 0.099, p = 0.756, ηp2 = 0.003; non-dominant: F(2,18) = 0.233, p = 0.632, ηp2 = 0.006, small effects). Conclusions: XKS significantly improves cognitive status measured by the MMSE and physical performance through reduced time in TUG and fear of falling through the FES-I in physically inactive older females
Effects of active video games combined with conventional physical therapy on perceived functionality in older adults with knee or hip osteoarthritis: a randomized controlled trial
No full textBackground: Osteoarthritis (OA) leads to functional decline in older adults. This study aimed to evaluate the effectiveness of active video games (AVGs) as a complement to conventional physical therapy (CPT) in improving functional disability. Methods: Sixty participants were randomly assigned to an experimental group (EG, n = 30, 68.7 ± 5.4 years), which received CPT combined with AVGs, or to a control group (CG, n = 30, 69.0 ± 5.5 years), which received CPT alone. Sessions were performed three times a week for ten weeks. Functional disability was assessed using the WOMAC index before, during, and after the intervention. Secondary outcomes included the Global Rating of Change (GRoC), the Minimal Clinically Important Difference, and patient trajectories through functional disability strata. Results: The EG showed progressive improvements in all WOMAC scores, with moderate to large increases by the end of the intervention, while the CG only showed significant changes in the later stages. The EG demonstrated greater improvements in WOMAC pain and the GroC scale (p < 0.05), maintaining most of the gains at follow-up, whereas the CG showed regression. Additionally, the EG had a higher proportion of responders, particularly for pain, while the CG had a predominance of non-responders and adverse responders. In the EG, 70% improved their functional disability stratification compared to 50% in the CG. Conclusion: Integration of AVGs with CPT further improves perceived functional disability in older adults with OA. Future research should explore these findings further
Distribution and bioconcentration of semivolatile organic compounds (SVOCs) in soils and vascular plant Colobanthus quitensis from Sub-Antarctic and Antarctic regions
No full textSemi-volatile organic compounds (SVOCs) are widely distributed across the globe, including polar regions. This study investigates the distribution and bioconcentration of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) in soils and Colobanthus quitensis, while also estimating potential emission sources. Results indicated high concentrations of PAHs in soils and plants from the Sub-Antarctic region, while OCPs and PCBs were more prevalent in the Antarctic region, with higher contaminant concentrations found in soils than in plant tissues. Hexachlorobenzene (HCB) and dichlorodiphenyldichloroethylene (p,p′-DDE) were significantly higher in the Antarctic region, suggesting historical dichlorodiphenyltrichloroethane (DDT) use, while PCB 153 and 180 were the most representative PCBs in the Antarctic region. Phenanthrene (Phe) was the dominant PAH in both regions. The bioconcentration factor analysis from soils (BCFSoils) revealed potential anthropogenic influences for certain contaminants, including γ-hexachlorocyclohexane (γ-HCH) and PCB 9 in the Sub-Antarctic region, and HCB, p,p′-DDE, PCB 9, and benzo-naphtho-thiophene in the Antarctic region. However, compounds with higher hydrophobicity showed lower Bioconcentration factor (BCFSoils) values, indicating a tendency to accumulate in soil rather than plant tissues. This was consistent with the inverse relationship found between BCFSoils and the octanol-water partition coefficient (Log KOW). Diagnostic ratios of PAHs revealed a predominantly pyrogenic source in the Sub-Antarctic region, while a mixture of sources was observed in the Antarctic region
Anxiety disorder, depression and coronary artery disease: associations and modification by genetic susceptibility
Full text linkBackground
Associations of anxiety disorder and depression with coronary artery disease (CAD) are heterogeneous between populations. This study investigated how genetic susceptibility to CAD alters these associations with incident CAD, comparing and combining anxiety disorder and depression.
Methods
This is a prospective cohort study using UK Biobank. Diagnoses of anxiety disorder and depression were ascertained through linked hospital admission data. Incident CAD was ascertained through hospital admission and death certificate data after baseline. CAD polygenic risk score (PRSCAD) was obtained from CARDIoGRAMplus4 and categorised into low, intermediate, and high. Cox proportional hazard models were used to examine associations between anxiety disorder and depression and CAD.
Results
Both anxiety disorder (HR 2.31, 95% CI 1.92–2.78) and depression (HR 2.15, 95% CI 1.90–2.24) were associated with CAD after adjusting for sociodemographic confounders. There was an addictive interaction between depression and PRSCAD (RERI 0.97, 95% CI 0.12–1.81) such that the association between depression and CAD was strongest among those with a high PRSCAD whilst there was no such evidence for anxiety disorder. Anxiety disorder only (HR 1.68, 95% 1.16–2.44), depression only (HR 2.13, 95% CI 1.72–2.64), and concomitant anxiety disorder and depression (HR 3.85, 95% CI 2.48–5.98) were associated with CAD even among people with a low PRSCAD. Adjusting for potential mediators attenuated all these associations across PRS categories.
Conclusions
CAD genetic susceptibility might partly contribute to the clustering of depression and CAD but does not provide a full explanation, nor does it explain the association between anxiety disorder and CAD. Therefore, other mechanisms should be explored
Phenogenetics of cortical granule dynamics during zebrafish oocyte-to-embryo transition
No full textFertilization is a critical process in sexual reproduction that involves the fusion of a capacitated sperm with a mature oocyte to form a zygote. Polyspermy, the fertilization of an oocyte by multiple sperm, leads to polyploidy and embryo lethality. Mammalian and non-mammalian oocytes have evolved mechanisms to prevent polyspermy, including fast and slow blocks. The fast block comprises membrane depolarization post-sperm fusion, temporarily preventing additional sperm fusion. The slow block, triggered by cortical granule (CG) exocytosis, involves the release of proteins that modify the zona pellucida to form a permanent barrier, avoiding the fertilization by additional sperm. The evidence shows that immature oocytes often fail to prevent polyspermy due to ineffective CG exocytosis, attributed to impaired intracellular calcium increases, lower content of this ion, and incomplete CG migration. The study of how genetic variations lead to observable phenotypes (phenogenetics) during the oocyte-to-embryo transition, have identified several maternal-effect genes in zebrafish involved in CG behavior. These genes regulate various stages of CG biology, including biosynthesis, maturation, and exocytosis. Mutations in these genes disrupt these processes, highlighting the maternal genetic control over CG properties. Zebrafish has emerged as a pivotal model for understanding the evolving genetic regulation and molecular mechanisms underlying CG biology, providing valuable insights into fertility and early embryonic development