Factores que influyen en la floración y el establecimiento de la regeneración en bosques primarios y manejados de Nothofagus pumilio

Martínez Pastur, G.; Lencinas, M. V. y Soler Esteban, R.CADIC-CONICET. Av. Houssay 200 (9410) Ushuaia, Argentina. E-mail: [email protected]. Cellini, J. M. UNLP, La Plata, Argentina.El manejo forestal de los bosques de Nothofagus pumilio se basa en su regeneración natural, pudiendo existir factores internos o externos, bióticos o abióticos que influyan sobre la misma. Para determinar los factores limitantes es necesario realizar una aproximación al ciclo completo. En este trabajo se analizaron patrones de floración, fructificación y establecimiento de la regeneración durante una estación de crecimiento en bosques primarios (BP) y manejados con retención agregada (RA) y dispersa (RD). Del total de flores femeninas producidas (BP=21,5 mill.ha-1, RA=6,5 mill.ha-1 y RD=2,9 mill.ha1) el 95%-97% produjo frutos. De estos, entre el 72%-79% llegó a semillas maduras, ocasionándose la pérdida por abscisión de frutos inmaduros (14%-20%), ataque de insectos (1,3%-4,9%) o consumo por aves (1,6%-3,5%). De las semillas maduras que llegaron al suelo, muchas no eran viables o estaban vacías (20%-31%). Durante la estratificación invernal también disminuyó la viabilidad (16%-33%), mientras que la pérdida por consumo de ratones y aves en este período fue menor en RA y BP (1,6%-2,3%) que en RD (7,4%). Las flores que formaron semillas disponibles para germinar variaron entre tratamientos: BP=23,5%, RA=23,5% y RD=19,3% del total de flores, siendo el establecimiento efectivo de plántulas del BP=2,6%, RA=1,8% y RD=0,7%. La principal limitante del ciclo fue la pérdida de viabilidad, durante la maduración del fruto (principalmente en los bosques manejados) y la estratificación invernal, así como la instalación de nuevas plántulas, tanto en BP como en RD. Estudios a largo plazo son necesarios para establecer las variaciones de estos ciclos en años con diferente producción de semillas.Estudio financiado por el proyecto PAE2004 22428 (SECYT-Argentina), y gracias a la colaboración del Aserradero Kareken (Tierra del Fuego - Argentina)

Uso de fotos hemiesféricas para la elaboración de modelos de altura de la regeneración en Nothofagus pumilio

Martínez Pastur, G.; Lencinas, M.V.; Soler Esteban, R. CADIC-CONICET. Casilla 92 (9410) Ushuaia, Argentina. [email protected]. Cellini, J.M.; Barrera, M. Universidad Nacional de La Plata, La Plata. Argentina. Peri, P. UNPA-INTA-CONICET, Río Gallegos, Argentina.El crecimiento en altura de la regeneración es la principal variable empleada para caracterizar la continuidad de bosques primarios y manejados. Entre los condicionantes bióticos y abióticos, la cobertura del dosel determina la cantidad de luz disponible. Se desarrollaron modelos de predicción de altura de regeneración de Nothofagus pumilio en relación con parámetros de cobertura y radiación obtenidos mediante fotos hemiesféricas, para bosques primarios y manejados. Se emplearon 3700 pares de datos (edad-altura) obtenidos durante 2002-2007 en parcelas permanentes de muestreo (n=16), caracterizadas con fotos hemiesféricas empleando un lente Sigma 8mm y analizadas usando el programa Gap Light Analyzer v.2.0. Se ajustaron modelos (Altura=a.Edadb.(c+d.X+e.X²)) por medio de técnicas de regresión no-linear que utilizaron como variables independientes a la altura y la edad de las plántulas, y como variables dependientes a la cobertura de copas (CC), el índice de área foliar efectivo (IAF), la radiación global (RG) y el porcentaje de radiación global incidente (PRG). Los modelos ajustados tuvieron un ajuste aceptable (r²=61%-63%) generando curvas polimórficas donde H aumentó hasta un máximo (20-25 cm en plántulas de 6 en CC 55%, LAI 1.0, GR 12.0 W.m² o PGR 50%) para luego decrecer en todas las edades analizadas con mayores o menores valores de dichas variables. Los bosques primarios presentaron CC=89.5%, LAI=2.6, GR=3.5 W.m² y PGR=14.3%, mientras que la corta de protección presentó CC=56.5%, LAI=0.8, GR=14.1 W.m² and PGR= 57.2%. El desarrollo de estos modelos es una herramienta útil para diseñar nuevas estrategias de manejo forestal al predecir la respuesta de la regeneración.Estudio financiado por el proyecto PAE2004 22428 (SECYT-Argentina), y gracias a la colaboración de la Consultora “Servicios Forestales” y el Aserradero Los Castores (Tierra del Fuego - Argentina)

Methodology of the Virtual Reconstruction of Arquitectonic Heritage: Ambassador Vich's Palace in Valencia

The 19th century was disastrous as far as the conservation of architectonic heritage is concerned. The awareness of the importance of preserving monuments that has prevailed since the end of the last century was dazzlingly absent in the previous, leading both to the disappearance of representative heritage works and the plundering of many others. The present study establishes the methodological basis to proceed with the virtual reconstruction of many disappeared architectures, representative of emblematic architectonic typologies. A method based on the combination of deduction and induction allows benchmarks to be created that signify a starting point to which the key and specific elements of each building are later incorporated, from the data extracted from the conserved parts and the graphic, literary and archive documents. The result is the virtual recovery of the general outlines of the architecture: morphology of the plot, volumetry, exterior and interior facades, and the functional layout. The good results obtained in the study of the disappeared Ambassador Vich's Palace, allow the methodology to be extended to the analysis of other similar examples, serving investigators as a tool to carry out an arduous task of deciphering a trail that is increasingly fading with the passing of time.Galiana Agullo, M.; Mas Tomas, MDLA.; Lerma Elvira, C.; Peñalver Martínez, MJ.; Conesa Tejada, S. (2014). Methodology of the Virtual Reconstruction of Arquitectonic Heritage: Ambassador Vich's Palace in Valencia. International Journal of Architectural Heritage. 8(1):94-123. doi:10.1080/15583058.2012.672623S9412381Boix, V. 1979.Historical and topographic Valencia[in Spanish]. Vol. I261 S. A. Printing J. Rius.Estaban Chapapría, J. (2001). Impostación del patio del Embajador Vich en el ex-convento del Carmen (Valencia). Loggia, Arquitectura & Restauración, (12), 26. doi:10.4995/loggia.2001.3605Morrish, S. W., & Laefer, D. F. (2010). Web-Enabling of Architectural Heritage Inventories. International Journal of Architectural Heritage, 4(1), 16-37. doi:10.1080/15583050902731056Lotz, W. 1995.Architecture in Italy 1500–1600 [in Italian]35–37. ed. RizzoliYale University Press.Lourenço, P. B., Peña, F., & Amado, M. (2010). A Document Management System for the Conservation of Cultural Heritage Buildings. International Journal of Architectural Heritage, 5(1), 101-121. doi:10.1080/15583050903318382Vila Ferrer, S. (2001). La recuperación del patio del palacio del Embajador Vich (Valencia). Loggia, Arquitectura & Restauración, (12), 44. doi:10.4995/loggia.2001.3606Zonta, D., Pozzi, M., & Zanon, P. (2008). Managing the Historical Heritage Using Distributed Technologies. International Journal of Architectural Heritage, 2(3), 200-225. doi:10.1080/1558305080206369

Solitary waves in the Nonlinear Dirac Equation

In the present work, we consider the existence, stability, and dynamics of solitary waves in the nonlinear Dirac equation. We start by introducing the Soler model of self-interacting spinors, and discuss its localized waveforms in one, two, and three spatial dimensions and the equations they satisfy. We present the associated explicit solutions in one dimension and numerically obtain their analogues in higher dimensions. The stability is subsequently discussed from a theoretical perspective and then complemented with numerical computations. Finally, the dynamics of the solutions is explored and compared to its non-relativistic analogue, which is the nonlinear Schr{\"o}dinger equation. A few special topics are also explored, including the discrete variant of the nonlinear Dirac equation and its solitary wave properties, as well as the PT-symmetric variant of the model

The IRYSS-COPD appropriateness study: objectives, methodology, and description of the prospective cohort

<p>Abstract</p> <p>Background</p> <p>Patients with chronic obstructive pulmonary disease (COPD) often experience exacerbations of the disease that require hospitalization. Current guidelines offer little guidance for identifying patients whose clinical situation is appropriate for admission to the hospital, and properly developed and validated severity scores for COPD exacerbations are lacking. To address these important gaps in clinical care, we created the IRYSS-COPD Appropriateness Study.</p> <p>Methods/Design</p> <p>The RAND/UCLA Appropriateness Methodology was used to identify appropriate and inappropriate scenarios for hospital admission for patients experiencing COPD exacerbations. These scenarios were then applied to a prospective cohort of patients attending the emergency departments (ED) of 16 participating hospitals. Information was recorded during the time the patient was evaluated in the ED, at the time a decision was made to admit the patient to the hospital or discharge home, and during follow-up after admission or discharge home. While complete data were generally available at the time of ED admission, data were often missing at the time of decision making. Predefined assumptions were used to impute much of the missing data.</p> <p>Discussion</p> <p>The IRYSS-COPD Appropriateness Study will validate the appropriateness criteria developed by the RAND/UCLA Appropriateness Methodology and thus better delineate the requirements for admission or discharge of patients experiencing exacerbations of COPD. The study will also provide a better understanding of the determinants of outcomes of COPD exacerbations, and evaluate the equity and variability in access and outcomes in these patients.</p

The 2021 eruption of the Cumbre Vieja volcanic ridge on La Palma, Canary Islands

Almost exactly half a century after the eruption of the Teneguía Volcano on La Palma (26 October to 28 November 1971), a new eruption occurred on the island and lasted for 85 days from 19 September until 13 December 2021. This new eruption opened a volcanic vent complex on the western flank of the Cumbre Vieja rift zone, the N-S elongated polygenetic volcanic ridge that has developed on La Palma over the last c. 125 ka. The Cumbre Vieja ridge is the volcanically active region of the island and the most active one of the Canary Islands, hosting half of all the historically recorded eruptive events in the archipelago. The 2021 La Palma eruption has seen no direct loss of human life, thanks to efficient early detection and sensible management of the volcanic crisis by the authorities, but more than 2800 buildings and almost 1000 hectares of plantations and farmland were affected by lava flows and pyroclastic deposits. Satellite surveillance enabled accurate mapping of the progressive buildup of the extensive and complex basaltic lava field, which together with monitoring of gas emissions informed the timely evacuation of local populations from affected areas. Lava flows that reached the sea constructed an extensive system of lava deltas and platforms, similar to events during earlier historical eruptions such as in 1712, 1949 and 1971. Long-term challenges in the aftermath of the eruption include protection of drainage systems from potential redistribution of tephra during high rainfall events, the use of the large surplus quantities of ash in reconstruction of buildings and in agriculture, and the crucial concerns of where and how rebuilding should and could occur in the aftermath of the eruption. Finally, there remain strong financial concerns over insurance for properties consumed or damaged by the eruption in the light of future volcanic hazards from the Cumbre Vieja volcanic ridge.Peer reviewe

Finding the best thresholds of FEV1 and dyspnea to predict 5-year survival in COPD patients: the COCOMICS study

BACKGROUND: FEV1 is universally used as a measure of severity in COPD. Current thresholds are based on expert opinion and not on evidence. OBJECTIVES: We aimed to identify the best FEV1 (% predicted) and dyspnea (mMRC) thresholds to predict 5-yr survival in COPD patients. DESIGN AND METHODS: We conducted a patient-based pooled analysis of eleven COPD Spanish cohorts (COCOMICS). Survival analysis, ROC curves, and C-statistics were used to identify and compare the best FEV1 (%) and mMRC scale thresholds that predict 5-yr survival. RESULTS: A total of 3,633 patients (93% men), totaling 15,878 person-yrs. were included, with a mean age 66.4 ± 9.7, and predicted FEV1 of 53.8% (± 19.4%). Overall 975 (28.1%) patients died at 5 years. The best thresholds that spirometrically split the COPD population were: mild ≥ 70%, moderate 56-69%, severe 36-55%, and very severe ≤ 35%. Survival at 5 years was 0.89 for patients with FEV1 ≥ 70 vs. 0.46 in patients with FEV1 ≤ 35% (H.R: 6; 95% C.I.: 4.69-7.74). The new classification predicts mortality significantly better than dyspnea (mMRC) or FEV1 GOLD and BODE cutoffs (all p<0.001). Prognostic reliability is maintained at 1, 3, 5, and 10 years. In younger patients, survival was similar for FEV1 (%) values between 70% and 100%, whereas in the elderly the relationship between FEV1 (%) and mortality was inversely linear. CONCLUSIONS: The best thresholds for 5-yr survival were obtained stratifying FEV1 (%) by ≥ 70%, 56-69%, 36-55%, and ≤ 35%. These cutoffs significantly better predict mortality than mMRC or FEV1 (%) GOLD and BODE cutoffs

History Shaped the Geographic Distribution of Genomic Admixture on the Island of Puerto Rico

Contemporary genetic variation among Latin Americans human groups reflects population migrations shaped by complex historical, social and economic factors. Consequently, admixture patterns may vary by geographic regions ranging from countries to neighborhoods. We examined the geographic variation of admixture across the island of Puerto Rico and the degree to which it could be explained by historic and social events. We analyzed a census-based sample of 642 Puerto Rican individuals that were genotyped for 93 ancestry informative markers (AIMs) to estimate African, European and Native American ancestry. Socioeconomic status (SES) data and geographic location were obtained for each individual. There was significant geographic variation of ancestry across the island. In particular, African ancestry demonstrated a decreasing East to West gradient that was partially explained by historical factors linked to the colonial sugar plantation system. SES also demonstrated a parallel decreasing cline from East to West. However, at a local level, SES and African ancestry were negatively correlated. European ancestry was strongly negatively correlated with African ancestry and therefore showed patterns complementary to African ancestry. By contrast, Native American ancestry showed little variation across the island and across individuals and appears to have played little social role historically. The observed geographic distributions of SES and genetic variation relate to historical social events and mating patterns, and have substantial implications for the design of studies in the recently admixed Puerto Rican population. More generally, our results demonstrate the importance of incorporating social and geographic data with genetics when studying contemporary admixed populations