Repositorio Académico de la Universidad Católica del Maule
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Reviews and syntheses: review of proxies for low-oxygen paleoceanographic reconstructions
No full textA growing body of observations has revealed rapid changes in both the total inventory and the distribution of marine oxygen over the latter half of the 20th century, leading to increased interest in extending oxygenation records into the past. The use of paleo-oxygen proxies has the potential to extend the spatial and temporal range of current records, constrain pre-anthropogenic baselines, provide datasets necessary to test climate models under different boundary conditions, and ultimately understand how ocean oxygenation responds beyond decadal-scale changes. This review seeks to summarize the current state of knowledge about proxies for reconstructing Cenozoic marine oxygen: sedimentary features, sedimentary redox-sensitive trace elements and isotopes, biomarkers, nitrogen isotopes, foraminiferal trace elements, foraminiferal assemblages, foraminiferal morphometrics, and benthic foraminiferal carbon isotope gradients. Taking stock of each proxy reveals some common limitations as the majority of proxies functions best at low-oxygen concentrations, and many reflect multiple environmental drivers. We also highlight recent breakthroughs in geochemistry and proxy approaches to constraining pelagic (in addition to benthic) oxygenation that are rapidly advancing the field. In light of both the emergence of new proxies and the persistent multiple driver problem, the need for multi-proxy approaches and data storage and sharing that adhere to the principles of findability, accessibility, interoperability, and reusability (FAIR) is emphasized. Continued refinements of proxy approaches and both proxy–proxy and proxy–model comparisons are likely to support the growing needs of both oceanographers and paleoceanographers interested in paleo-oxygenation records
The mountain papaya may be a possible reservoir of the Kashmir bee virus
No full textBackground
The Kashmir bee virus (KBV) infects many species of Hymenoptera, including bees, wasps, and other pollinators, potentially contributing to honeybee population declines. KBV can cause death of bees. KBV can infect through both vertical transmission (from queen to larvae and vice versa) and horizontal transmission (via food contamination). Plants pollinated by bees may be a source of horizontal transmission, through fecal contamination of pollen and flowers by infected pollinators, both intra- and interspecifically. Pollinated plants constitute a source of KBV intra- and inter-species horizontal transmission, particularly by the contamination of pollen and flowers by feces of KBV-infected pollinators.
Result
We test for the presence of KBV sequences in the transcriptomes of Vasconcellea pubescens, a commercially valuable plant species known as mountain papaya. We mapped transcriptomes from fruit, leaves, and root tissues to the KBV reference genome with 91% coverage, from which we produced a consensus sequence denominated Kashmir bee virus ch. phylogenetic analysis revealed that KBV-Ch shares 97% nucleotide identity with the reference genome, and groups with other KBV strains isolated from Spain, Chile and New Zealand
Fingerprint classification based on multilayer extreme learning machines
No full textFingerprint recognition is one of the most effective and widely adopted methods for person identification. However, the computational time required for the querying of large databases is excessive. To address this, preprocessing steps such as classification are necessary to speed up the response time to a query. Fingerprints are typically categorized into five classes, though this classification is unbalanced. While advanced classification algorithms, including support vector machines (SVMs), multilayer perceptrons (MLPs), and convolutional neural networks (CNNs), have demonstrated near-perfect accuracy (approaching 100%), their high training times limit their widespread applicability across institutions. In this study, we introduce, for the first time, the use of a multilayer extreme learning machine (M-ELM) for fingerprint classification, aiming to improve training efficiency. A comparative analysis is conducted with CNNs and unbalanced extreme learning machines (W-ELMs), as these represent the most influential methodologies in the literature. The tests utilize a database generated by SFINGE software, which simulates realistic fingerprint distributions, with datasets comprising hundreds of thousands of samples. To optimize and simplify the M-ELM, widely recognized descriptors in the field—Capelli02, Liu10, and Hong08—are used as input features. This effectively reduces dimensionality while preserving the representativeness of the fingerprint information. A brute-force heuristic optimization approach is applied to determine the hyperparameters that maximize classification accuracy across different M-ELM configurations while avoiding excessive training times. A comparison is made with the aforementioned approaches in terms of accuracy, penetration rate, and computational cost. The results demonstrate that a two-layer hidden ELM achieves superior classification of both majority and minority fingerprint classes with remarkable computational efficiency
The mediating role of work–life balance between perceived partner support and satisfaction with food-related life in dual-earning parents and their adolescents
No full textBackground: Partner support and work–life balance (WLB) are important for families’ well-being. Previous research has linked perceived family support, WLB, and satisfaction with food-related life (SWFoL); however, there is limited information regarding each parent’s support from their partner. Drawing on the conservation of resources theory, the work–home resources, and the actor–partner interdependence model (APIM), this study examined the direct and indirect effects of parents’ perceived partner support, WLB, and the SWFoL of dual-income parents and their adolescents, considering the moderating role of parents’ gender-transcendent attitudes. Methods: A total of 516 dual-earning parents with one adolescent child were recruited in Chile using non-probability sampling. The parents completed scales measuring perceived partner support, WLB, and gender role attitudes. The three family members responded to the Satisfaction with Food-Related Life scale. The data were analyzed using the mediation APIM, structural equation modeling, and multi-group analysis. Results: The model fit was robust (RMSEA = 0.016; SRMR = 0.052; CFI = 0.982; TLI = 0.978). The findings showed that the mothers’ SWFoL was indirectly and positively affected by their and the fathers’ perceived partner support through both parents’ WLB. The fathers’ SWFoL was directly and positively affected by their perceived partner support and indirectly via their WLB. The adolescents’ SWFoL was directly and positively affected by the mothers’ perceived partner support and indirectly by the fathers’ perceived partner support through the fathers’ WLB. In families where the fathers exhibited low gender-transcendent attitudes, the relationship between the mothers’ perceived partner support and WLB was stronger. Conclusions: Thus, it can be concluded that the mediating role of work–life balance is significant, as it facilitates the transmission of resources within and between individuals to enhance parents’ and adolescents’ SWFoL
Didactic intervention to promote knowledge of the common Pilpilén shorebird (Haematopus palliatus) in primary schoolchildren in central-southern Chile
No full textEl objetivo del presente trabajo fue evaluar el impacto de una secuencia didáctica para fomentar el conocimiento de la especie Haematopus palliatus (Pilpilén común), considerando el dibujo de tipo realista como medio de representación mental. Para ello se aplicaron, al inicio y termino de la implementación de la secuencia, instrumentos de evaluación como: técnica de conceptualización breve, representación gráfica de la especie y su entorno y preguntas abiertas, a 31 estudiantes de cuarto año de enseñanza primaria. Los resultados muestran la existencia de diferencias significativas (p<0,001) entre las representaciones gráficas del entorno y de las características de la especie, antes y después de la intervención didáctica; lo que indica que la estrategia utilizada logró movilizar cambios en los conceptos iniciales del estudiantado, quienes solo relacionaban al Pilpilén común con un modelo de ave urbana, ajeno a lo que es un ave playera. Asimismo, los resultados en los aprendizajes del estudiantado apoyan la idea de que un diseño de la enseñanza con perspectiva constructivista habilita un aprendizaje contextualizado tanto de los resultados de aprendizajes, como de las ideas científicas presentes en el currículum chileno
"That'd be another crisis nearly avoided": humor and conflict management in hospital handover meetings
No full textThe topic of humor (and laughter) in healthcare contexts has attracted considerable scholarly interest, especially in professional-patient communication. Yet much remains to be investigated about its forms and functions in backstage inter-professional interaction from a discourse analytical/pragmatic perspective. In this light, this paper explores the role of humor in interpersonal conflict management in hospital handover meetings with the aim of providing insights into both the various functions this inconspicuous discursive strategy may perform on a macro-level, as well as the way this is achieved at the micro-level. Interpersonal conflict is said to be an inherent aspect of such high-stakes medical settings, and conflict management is of vital importance for negotiating patients’ cases and treatment paths. Drawing on authentic handover meetings recorded at a hospital in New Zealand, we provide useful insights into the ways in which conflicts are managed and medical knowledge is transferred in these backstage encounters. The paper shows how different kinds of potentially face-threatening humor is used to manage and avoid conflict by those in superior as well as those in more junior positions. Finally, we argue that these ways of ‘doing’ humor in conflict management are a reflection (and reinforcement) of the team’s close-knit social relations and directly address the high-stakes nature of these medical encounters
Integrating machine learning with MALDI-TOF mass spectrometry for rapid and accurate antimicrobial resistance detection in clinical pathogens
No full textAntimicrobial resistance (AMR) is one of the most pressing public health challenges of the 21st century. This study aims to evaluate the efficacy of mass spectral data generated by VITEK® MS instruments for predicting antibiotic resistance in Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae using machine learning algorithms. Additionally, the potential of pre-trained models was assessed through transfer learning analysis. A dataset comprising 2229 mass spectra was collected, and classification algorithms, including Support Vector Machines, Random Forest, Logistic Regression, and CatBoost, were applied to predict resistance. CatBoost demonstrated a clear advantage over the other models, effectively handling complex non-linear relationships within the spectra and achieving an AUROC of 0.91 and an F1 score of 0.78 for E. coli. In contrast, transfer learning yielded suboptimal results. These findings highlight the potential of gradient-boosting techniques to enhance resistance prediction, particularly with data from less conventional platforms like VITEK® MS. Furthermore, the identification of specific biomarkers using SHAP values indicates promising potential for clinical applications in early diagnosis. Future efforts focused on standardizing data and refining algorithms could expand the utility of these approaches across diverse clinical environments, supporting the global fight against AMR
Interculturality and pedagogical practices in Chilean preschool education
No full textIntroduction: currently in the educational field, boys and girls face new cultures, customs, and languages, through intercultural classrooms from the first years of Chilean education, this due to the growing migration and appreciation of native peoples.
Objective: the study aims to describe the intercultural practices carried out by early childhood educators at different levels of early childhood education in educational establishments in the commune of Curicó, Maule region, Chile.
Methods: research responds to a qualitative investigation, case study, descriptive, through a semi-structured interview with five early childhood educators, which responds to being an intentional sample.
Results: the results show that the preschool educators carry out intercultural practices occasionally, focused on festivities and using mostly audiovisual resources.
Conclusions: Based on the above, we can conclude with the need to incorporate intercultural practices permanently and constantly in a transversal manner, independent of the pedagogical topic that is being worked on with the boys and girls
Clam fishing along 1300 km Chilean coastline: a morphometric and genetic survey of Mulinia edulis King, 1832
No full textMulinia edulis, also known as Taquilla clam, is a fishery resource, and one of the 6 species of clams commercially exploited in Chile. Valuable advances have been made for its culture, but there is still uncertainty regarding the species associated with the main commercial banks. The hypothesis was that, if the different harvested banks of M. edulis correspond to a single species along the Chilean coast, when comparing individuals from the north, central and south, they should not present significant morphological differences in their valves. The aim of this paper is to analyze and compare the morphology of M. edulis valves using geometric morphology and genetic comparison by sequencing the mitochondrial gene Cytochrome oxidase I and 16S RNA gene. Samples were obtained in three main fishery grounds, Tongoy Bay (northern), Arauco Gulf (central) and Ancud Bay (southern). In the inner side of the right valve 28 morphological landmarks were set, using TPS Util and R package geomorph, landmarks settings were overlaid through the generalized Procrustes analysis. Principal Components Analysis (PCA), using residuals were conducted among locations and sex. The results show no in-fluence of size or sex on shape of the valves. Through PCA analysis banks were differentiated by their shape. Abductor muscle and pallial sinus show the most relevant differences, especially when comparing northern and southern clams, where Arauco Gulf shows an intermediate morph. The three localities show low genetic diversity and little differentiation between them. This finding suggests that the fishery of taquilla clam is sustained only by M. edulis
Analysis of sleep quality and its impact on body composition on the pre-competition day in natural bodybuilders
No full textIntroducción: El culturismo es un deporte que evalúa a los atletas en función de su masa muscular, simetría y definición muscular, a diferencia de los deportes convencionales que suelen basarse en el rendimiento deportivo en competencia.
Objetivo: El objetivo fue determinar la relación entre la masa grasa (FM) y la masa muscular esquelética (SMM) por medio de bioimpedancia con la calidad del sueño en fisicoculturistas naturales el día previo a la competencia.
Metodología: Veintiséis culturistas naturales participaron en el campeonato WNBF. Se evaluó la composición corporal para obtener datos de SMM y FM. Además, se aplicó el PSQI.
Resultados: Se obtuvieron relaciones significativas entre SMM y PSQI (p= 0.02, R = -0.38, R²= 0.14) y una correlación moderada entre FM y PSQI (p= 0.04, R = 0.40, R²= 0.15). La eficiencia del sueño mostró una correlación negativa (p= 0.001, R = -0.55, R²= 0.31) con la FM y una correlación positiva (p = 0.002, R = 0.58, R²= 0.34) con el SMM. La duración del sueño mostró una correlación negativa (p = 0.024, R = -0.39, R²= 0.15) con la FM y una correlación positiva ((p = 0.021, R = 0.45, R²= 0.20) con el SMM.
Discusión: Se reporta que el sueño insuficiente afecta negativamente la composición corporal, con menos pérdida de grasa y menor ganancia muscular.
Conclusión: Una mala calidad del sueño se relaciona con una mayor grasa corporal y una mejor calidad del sueño con una mayor masa muscular, lo que subraya la importancia del sueño para lograr una composición corporal y un rendimiento óptimos en los culturistas naturales