Recent consequences of climate change have affected tree growth in distinct Nothofagus macrocarpa (DC.) FM Vaz & Rodr age classes in Central Chile

Forests play an important role in water and carbon cycles in semiarid regions such as the Mediterranean ecosystems. Previous research in the Chilean Mediterranean forests revealed a break point in 1980 in regional tree-ring chronologies linked to climate change. However, it is still unclear which populations and age classes are more affected by recent increases in drought conditions. In this study, we investigated the influence of recent variations in precipitation, temperature, and CO2 concentrations on tree growth of various populations and age classes of Nothofagus macrocarpa trees in Central Chile. We sampled 10 populations from five sites of N. macrocarpa through its whole geographic distribution in both Coastal and Andes ranges. We used standard dendrochronological methods to (i) group populations using principal component analysis, (ii) separate age classes (young, mature, and old trees), (iii) evaluate linear growth trends based on the basal area increment (BAI), and (iv) analyze the link between BAI and atmospheric changes using linear mixed-effects models. Results showed that young trees are more sensitive to climate variability. Regarding population grouping, we observed that all population clusters were sensitive to winter-spring precipitation, but only the Andes and Coastal populations were negatively correlated with temperature. The results of CO2 fertilization analyses were controversial and unclear. Since young trees from all population clusters reacted positively in the phase with an increase of atmospheric CO2 between 1980 and 2014, this behavior was not translated into growth for the last 15 years (2000-2014). However, it should be noted that the young trees of the highest elevation populations did not have a negative growth trend, so it seems that CO2 counteracted the negative effect of recent regional climate change (increase in temperature and precipitation decrease) in these population trees. Further studies are needed to assess the effects of climate variability over other ecological and physiological processes.Fil: Venegas González, Alejandro. Universidad Mayor.; ChileFil: Roig Junent, Fidel Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Peña Rojas, Karen. Universidad de Chile; ChileFil: Hadad, Martín Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; ArgentinaFil: Aguilera Betti, Isabella. Pontificia Universidad Católica de Valparaíso; Chile. Universidad Austral de Chile; ChileFil: Muñoz, Ariel A.. Pontificia Universidad Católica de Valparaíso; Chil

Análisis De Clases Latentes: Caracterización Para El Diseño E Implementación De Programas De Orientación Y Disminución Del Abandono En Educación Superior

El presente trabajo propone la metodología de Análisis de Clases Latentes (ACL), para demostrar que la autorregulación académica es un factor clave, tanto en la caracterización inicial de los estudiantes como en la articulación entre ella y el diseño e implementación de programas de orientación; relevando, de esta manera, la importancia que la autorregulación académica tiene para la generación de competencias y su relación con el riesgo de abandono universitario. Metodología: Se utilizó el Perfil de Autorregulación Académica (PAA) y los resultados de su aplicación a las cohortes 2016 y 2017 de Campus Sur de la Universidad de Chile (n=870). El ACL se empleó para identificar patrones de respuesta en los resultados obtenidos por los estudiantes y caracterizarlos para construir perfiles de riesgo de abandono. Resultados: De este análisis se deriva que el modelo con mejor ajuste a los datos (mejor BIC) es el de cuatro clases latentes. Este modelo permite identificar y validar que los factores derivados de los resultados del PAA son un indicador apropiado para caracterizar a los estudiantes. Además, se logra explorar las relaciones entre las variables incluidas en el análisis y sustentar la hipótesis planteada al inicio de la investigación. Conclusiones: La caracterización y posterior orientación en educación superior requieren profundizar su articulación, no solamente para mejorar su efectividad en la reducción del abandono, sino también para mejorar la calidad de vida universitaria y hacer más llevadera la transición a la educación superior. Para ello es necesario innovar y aplicar nuevas metodologías y técnicas que permitan tanto conocer detalladamente los perfiles de ingreso de los estudiantes como también determinar con precisión cuáles son las mejores alternativas de orientación una vez detectadas sus necesidades. Se concluye que el ACL es una metodología apropiada para el estudio y comprensión del abandono en educación superior, ya que permite, además de caracterizar a los estudiantes de primer año universitario, definir perfiles de riesgo de abandono para generar de manera oportuna y precisa, el diseño de programas de orientación basado en el desarrollo de habilidades de autorregulación académica

Effects of climate variability on growth and establishment patterns of nothofagus macrocarpa in central Chile

Se ha documentado un aumento de las condiciones de sequía durante el último siglo en Chile central, que estaría afectando al bosque mediterráneo, especialmente a los bosques septentrionales del género Nothofagus en América (Nothofagus macrocarpa). Por esta razón resulta imprescindible estudiar la influencia del clima en el crecimiento radial y establecimiento de árboles a fin de diseñar estrategias de conservación y mitigación al cambio climático. Diez poblaciones de N. macrocarpa fueron seleccionadas para analizar la relación entre las sequías y el crecimiento radial anual y la influencia de condiciones hídricas en el establecimiento. Se identificaron tres patrones de crecimiento: (i) poblaciones más degradadas de la Cordillera de la Costa, (ii) bosques poco intervenidos y que se encuentran a una mayor altitud de la Cordillera de la Costa, y (iii) poblaciones poco intervenidas de la Cordillera de Los Andes. Todas las poblaciones presentaron correlaciones positivas con el índice de sequía SPEI (índice estandarizado de precipitación-evapotranspiración) durante invierno-primavera, siendo sensibles hasta 36 meses después de un período seco. Más del 64 % de los años con bajo crecimiento en todas las cronologías fue asociado a sequías históricas. Se observó mayor establecimiento de N. macrocarpa vinculado a períodos húmedos especialmente en los bosques poco degradados. Estos resultados entregan una visión ecológica sobre la sensibilidad climática del bosque mediterráneo de Chile y pueden contribuir en el diseño de proyectos de restauración, conservación y mitigación frente al calentamiento global.An increase in drought conditions over the last century has been documented in Central Chile, a fact that could affect the Mediterranean forests, especially the northernmost Nothofagus populations from South America (Nothofagus macrocarpa). For this reason, it is key to study the climate influence on radial growth and trees establishment to design strategies of conservation and mitigation in the face of a climate change situation. In this study, 10 trees populations of N. macrocarpa were selected across natural distribution for a dendroecological analysis. The relationship between droughts and radial growth was analyzed annually, while the influence of water favorable conditions in trees establishment was evaluated in periods of 10 years. Results identified three growth patterns: (i) most degraded populations of the Coastal Mountains (young trees predominate), (ii) low-intervened forests found at a higher altitude in the Coastal Mountains and (iii) low-intervened forests of the Andes Mountains. All populations showed positive correlations with the SPEI-drought index during winter-spring, being sensitive up to 36 months after a dry period. More than 64% of the years with lowest growth are associated with historical droughts in all the chronologies, whereas trees establishment linked to humid periods was found especially in the less degraded forests (37-41% trees). These results provide an ecological vision of the climatic sensitivity of the Chilean Mediterranean forest and can contribute to the design restoration, conservation and mitigation actions in situations of global warming.Fil: Venegas González, Alejandro. Universidade de Sao Paulo; Brasil. Pontificia Universidad Católica de Valparaíso; ChileFil: Roig Junent, Fidel Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Gutiérrez, Alvaro G.. Universidad de Chile; ChileFil: Peña-Rojas, Karen. Universidad de Chile; ChileFil: Filho, Mario Tomazello. Universidade de Sao Paulo; Brasi

Similar incidence of coronavirus disease 2019 (COVID-19) in patients with rheumatic diseases with and without hydroxychloroquine therapy

Background Hydroxychloroquine is not efficacious as post-exposure prophylaxis against coronavirus disease 2019 (COVID-19). It is not known whether as pre-exposure prophylaxis it may prevent COVID-19. Objective To compare the incidence of COVID-19 in Spanish patients with autoimmune rheumatic diseases treated with and without hydroxychloroquine. Patients and methods Retrospective electronic record review, from February 27th to June 21st, 2020, of patients with autoimmune inflammatory diseases followed at two academic tertiary care hospitals in Seville, Spain. The cumulative incidence of confirmed COVID-19, by PCR or serology, was compared between patients with and without hydroxychloroquine as part of their treatment of autoimmune inflammatory diseases. Results Among 722 included patients, 290 (40%) were receiving hydroxychloroquine. During the seventeen-week study period, 10 (3.4% [95% CI: 1.7%-6.7%] cases of COVID-19 were registered among patients with hydroxychloroquine and 13 (3.0% [1.6%-5.1%]) (p = 0.565) in those without hydroxychloroquine. COVID-19 was diagnosed by PCR in four (1.4%, 95% CI 0.38%-3.5%) subject with hydroxychloroquine and six (1.4%, 95% CI 0.5%-3.0%) without hydroxychloroquine (p = 0.697). Three patients on hydroxychloroquine and four patients without hydroxychloroquine were admitted to the hospital, none of them required to be transferred to the intensive care unit and no patient died during the episode. Conclusions The incidence and severity of COVID-19 among patients with autoimmune rheumatic diseases with and without hydroxychloroquine was not significantly different.Instituto de Salud Carlos III I3SNSMinisterio de Ciencia, Innovación y Universidades CP18/0014

Hydroclimatic variations reveal differences in carbon capture in two concurrent conifers in northern Mexico

Forest ecosystems are considered among the largest terrestrial carbon sinks. The dynamics of forest carbon depend on where the carbon is stored and its responses to environmental factors, as well as the physiology of the trees. Thus, threatened forest regions with high biodiversity have great scientific importance, such as the Sierra Madre Occidental in Mexico. A comparative analysis of tree species can expand the knowledge of the carbon cycle dynamics and ecological processes in this region. Here, we examined the growth, wood density, and carbon accumulation of two threatened species (Pseudotsuga menziesii and Cupressus lusitanica) to evaluate their hydroclimatic responsiveness

Composición y actividad antifúngica del aceite esencial de Fabiana imbricata contra levaduras del género Candida

El objetivo de este estudio fue evaluar la actividad anti-fungica del aceite esencial (AE) de Fabiana imbricata Ruiz & Pav contra cinco especies de Candida comúnmente asociadas a enfermedades ginecológicas. El aceite esencial de las hojas fresca de F. imbricata fue obtenido por hidrodestilación y caracterizado mediante la técnica de cromatografía de gases acoplada a espectrometría de masas (CG/EM). Se evaluó la actividad anti-fúngica a diferentes concentraciones del AE mediante el método de microdilución. Los compuestos más abundantes identificados en el AE (7a-isopropenil-4,5-dimetiloctahidroinden-4-il) metanol (43,66%), bulnesol (17,02%) y T-muurolol (5,75%). El AE mostro una potente y selectiva actividad anti-fúngica sobre el crecimiento de la levadura patógena Candida guilliermondii con una concentración mínima inhibitoria de 10 μg/mL, superior al control positivo clotrimazol que presento un valor de 15 μg/mL. Estos resultados confirman las propiedades antimicrobianas de los aceites esenciales y su posible uso en el manejo de las cepas de C. guilliermondii de importancia para pacientes inmune deprimidos y como posibles alternativas a los fungicidas sintéticos

In1-ghrelin splicing variant is overexpressed in pituitary adenomas and increases their aggressive features

Pituitary adenomas comprise a heterogeneous subset of pathologies causing serious comorbidities, which would benefit from identification of novel, common molecular/cellular biomarkers and therapeutic targets. The ghrelin system has been linked to development of certain endocrine-related cancers. Systematic analysis of the presence and functional implications of some components of the ghrelin system, including native ghrelin, receptors and the recently discovered splicing variant In1-ghrelin, in human normal pituitaries (n 5 11) and pituitary adenomas (n 5 169) revealed that expression pattern of ghrelin system suffers a clear alteration in pituitary adenomasas comparedwith normal pituitary, where In1-ghrelin is markedly overexpressed. Interestingly, in cultured pituitary adenoma cells In1-ghrelin treatment (acylated peptides at 100 nM; 24–72 h) increasedGHandACTHsecretion, Ca21 and ERK1/2 signaling and cell viability, whereas In1-ghrelin silencing (using a specific siRNA; 100 nM) reduced cell viability. These results indicate that an alteration of the ghrelin system, specially its In1-ghrelin variant, could contribute to pathogenesis of different pituitary adenomas types, and suggest that this variant and its related ghrelin system could provide new tools to identify novel, more general diagnostic, prognostic and potential therapeutic targets in pituitary tumors

A Somatostatin Receptor Subtype-3 (SST3) Peptide Agonist Shows Antitumor Effects in Experimental Models of Nonfunctioning Pituitary Tumors

[Purpose] Somatostatin analogues (SSA) are efficacious and safe treatments for a variety of neuroendocrine tumors, especially pituitary neuroendocrine tumors (PitNET). Their therapeutic effects are mainly mediated by somatostatin receptors SST2 and SST5. Most SSAs, such as octreotide/lanreotide/pasireotide, are either nonselective or activate mainly SST2. However, nonfunctioning pituitary tumors (NFPTs), the most common PitNET type, mainly express SST3 and finding peptides that activate this particular somatostatin receptor has been very challenging. Therefore, the main objective of this study was to identify SST3-agonists and characterize their effects on experimental NFPT models.[Experimental Design] Binding to SSTs and cAMP level determinations were used to screen a peptide library and identify SST3-agonists. Key functional parameters (cell viability/caspase activity/chromogranin-A secretion/mRNA expression/intracellular signaling pathways) were assessed on NFPT primary cell cultures in response to SST3-agonists. Tumor growth was assessed in a preclinical PitNET mouse model treated with a SST3-agonist. [Results] We successfully identified the first SST3-agonist peptides. SST3-agonists lowered cell viability and chromogranin-A secretion, increased apoptosis in vitro, and reduced tumor growth in a preclinical PitNET model. As expected, inhibition of cell viability in response to SST3-agonists defined two NFPT populations: responsive and unresponsive, wherein responsive NFPTs expressed more SST3 than unresponsive NFPTs and exhibited a profound reduction of MAPK, PI3K-AKT/mTOR, and JAK/STAT signaling pathways upon SST3-agonist treatments. Concurrently, SSTR3 silencing increased cell viability in a subset of NFPTs. [Conclusions] This study demonstrates that SST3-agonists activate signaling mechanisms that reduce NFPT cell viability and inhibit pituitary tumor growth in experimental models that expresses SST3, suggesting that targeting this receptor could be an efficacious treatment for NFPTs.This work has been funded by the following grants: Junta de Andalucía [CTS-1406 (R.M. Luque), BIO-0139 (J.P. Castaño)]; Ministerio de Ciencia, Innovación y Universidades [BFU2016-80360-R (J.P. Castaño)] and Instituto de Salud Carlos III, co-funded by European Union [ERDF/ESF, “Investing in your future”: PI16/00264 (R.M. Luque), CP15/00156 (M.D. Gahete) and CIBERobn]. CIBER is an initiative of Instituto de Salud Carlos III

Performance of cervical cytology and HPV testing for primary cervical cancer screening in Latin America : an analysis within the ESTAMPA study

Corresponding author. E-mail address: [email protected] (A.T. Ramírez).Background. Cervical cytology remains widely used as the initial tool in cervical cancer screening worldwide. WHO guidelines recommend replacing cytology with primary HPV testing to reach cervical cancer elimination goals. We assessed the performance of cytology and high-risk HPV testing to detect cervical precancer, cervical intraepithelial neoplasia (CIN) grade 3 or worse (CIN3+) among women aged 30–64 years participating in the ESTAMPA study. Methods. Women were screened with cytology and HPV across ESTAMPA study centres in Latin America. Screen-positives were referred to colposcopy with biopsy collection and treatment as needed. Those with no evident precancer were recalled at 18-months for a second HPV test to complete disease ascertainment. Performance indicators for cytology and HPV to detect CIN3+ were estimated. Findings. 30,606 participants with available cytology and HPV results were included in the analysis. A total of 440 histologically confirmed CIN3s and 30 cancers were diagnosed. Cytology sensitivity for CIN3+ was 48.5% (95% CI: 44.0–53.0), whereas HPV testing had a sensitivity of 98.1% (95% CI: 96.3–96.7). Specificity was 96.5% (95% CI: 96.3–96.7) using cytology and 88.7% (95% CI: 88.3–89.0) with HPV. Performance estimates varied substantially by study centre for cytology (ranging from 32.1% to 87.5% for sensitivity and from 89.2% to 99.5% for specificity) while for HPV results were more consistent across sites (96.7%–100% and 83.6–90.8%, respectively). Interpretation. The limited and highly variable sensitivity of cytology strongly supports transition to the more robust and reproducible HPV-based cervical screening to ensure progress towards global cervical cancer elimination targets in Latin America.Consejo Nacional de Ciencia y TecnologíaPrograma Paraguayo para el Desarrollo de la Ciencia y Tecnología. Proyectos de investigación y desarroll

Performance of standardised colposcopy to detect cervical precancer and cancer for triage of women testing positive for human papillomavirus : results from the ESTAMPA multicentric screening study

Correspondence to: Dr Joan Valls, Early Detection, Prevention and Infections Branch, International Agency for Research on Cancer, Lyon 69366, France. [email protected]. Colposcopy, currently included in WHO recommendations as an option to triage human papillomavirus (HPV)-positive women, remains as the reference standard to guide both biopsy for confirmation of cervical precancer and cancer and treatment approaches. We aim to evaluate the performance of colposcopy to detect cervical precancer and cancer for triage in HPV-positive women. Methods. This cross-sectional, multicentric screening study was conducted at 12 centres (including primary and secondary care centres, hospitals, laboratories, and universities) in Latin America (Argentina, Bolivia, Colombia, Costa Rica, Honduras, Mexico, Paraguay, Peru, and Uruguay). Eligible women were aged 30–64 years, sexually active, did not have a history of cervical cancer or treatment for cervical precancer or a hysterectomy, and were not planning to move outside of the study area. Women were screened with HPV DNA testing and cytology. HPV-positive women were referred to colposcopy using a standardised protocol, including biopsy collection of observed lesions, endocervical sampling for transformation zone (TZ) type 3, and treatment as needed. Women with initial normal colposcopy or no high-grade cervical lesions on histology (less than cervical intraepithelial neoplasia [CIN] grade 2) were recalled after 18 months for another HPV test to complete disease ascertainment; HPV-positive women were referred for a second colposcopy with biopsy and treatment as needed. Diagnostic accuracy of colposcopy was assessed by considering a positive test result when the colposcopic impression at the initial colposcopy was positive minor, positive major, or suspected cancer, and was considered negative otherwise. The main study outcome was histologically confirmed CIN3+ (defined as grade 3 or worse) detected at the initial visit or 18-month visit. Findings. Between Dec 12, 2012, and Dec 3, 2021, 42 502 women were recruited, and 5985 (14·1%) tested positive for HPV. 4499 participants with complete disease ascertainment and follow-up were included in the analysis, with a median age of 40·6 years (IQR 34·7–49·9). CIN3+ was detected in 669 (14·9%) of 4499 women at the initial visit or 18-month visit (3530 [78·5%] negative or CIN1, 300 [6·7%] CIN2, 616 [13·7%] CIN3, and 53 [1·2%] cancers). Sensitivity was 91·2% (95% CI 88·9–93·2) for CIN3+, whereas specificity was 50·1% (48·5–51·8) for less than CIN2 and 47·1% (45·5–48·7) for less than CIN3. Sensitivity for CIN3+ significantly decreased in older women (93·5% [95% CI 91·3–95·3] in those aged 30–49 years vs 77·6% [68·6–85·0] in those aged 50–65 years; p<0·0001), whereas specificity for less than CIN2 significantly increased (45·7% [43·8–47·6] vs 61·8% [58·7–64·8]; p<0·0001). Sensitivity for CIN3+ was also significantly lower in women with negative cytology than in those with abnormal cytology (p<0·0001). Interpretation. Colposcopy is accurate for CIN3+ detection in HPV-positive women. These results reflect ESTAMPA efforts in an 18-month follow-up strategy to maximise disease detection with an internationally validated clinical management protocol and regular training, including quality improvement practices. We showed that colposcopy can be optimised with proper standardisation to be used as triage in HPV-positive women.Consejo Nacional de Ciencia y TecnologíaPrograma Paraguayo para el Desarrollo de la Ciencia y Tecnología. Proyectos de investigación y desarrollo14-INV-036PINV18-25