51 research outputs found
Red squirrel habitat mapping using remote sensing
The native Eurasian red squirrel is considered endangered in the UK and is under
strict legal protection. Long-term management of its habitat is a key goal of the UK
conservation strategy. Current selection criteria of reserves and subsequent
management mainly consider species composition and food availability. However,
there exists a critical gap in understanding and quantifying the relationship between
squirrel abundance, their habitat use and forest structural characteristics. This has
partly resulted from the limited availability of structural data along with cost-efficient
data collection methods. This study investigated the relationship between
squirrel feeding activity and structural characteristics of Scots pine forests. Field data
were collected from two study areas: Abernethy and Aberfoyle Forests. Canopy
closure, diameter at breast height, height and number of trees were measured in 56
plots. Abundance of squirrel feeding signs was used as an index of habitat use. A
GLM was used to model the response of cones stripped by squirrels in relation to the
field collected structural variables. Results show that forest structural characteristics
are significant predictors of feeding sign presence, with canopy closure, number of
trees and tree height explaining 43% of the variation in stripped cones. The GLM
was also implemented using LiDAR data to assess at wider scales the number of
cones stripped by squirrels. The use of remote sensing -in particular Light Detection
and Ranging (LiDAR) - enables cost efficient assessments of forest structure at large
scales and can be used to retrieve the three variables explored in this study; canopy
cover, tree height and number of trees, that relate to red squirrel feeding behaviour.
Correlation between field-predicted and LiDAR-predicted number of stripped cones
was performed to assess LiDAR-based model performance. LiDAR data acquired at
Aberfoyle and Abernethy Forests had different characteristics (in particular pulse
density), which influences the accuracy of LiDAR derived metrics. Therefore
correlations between field predicted and LiDAR predicted number of cones (LSC)
were assessed for each study area separately. Strong correlations (rs=0.59 for
Abernethy and 0.54 for Aberfoyle) suggest that LiDAR-based model performed
relatively well over the study areas. The LiDAR-based model was not expected to provide absolute numbers of cones stripped by squirrels but a relative measure of
habitat use. This can be interpreted as different levels of habitat suitability for red
squirrels. LiDAR-based GLM maps were classified into three levels of suitability:
unsuitable (LSC = 0), Low (LSC =10).
These thresholds were defined based on expert knowledge. Such a classification of
habitat suitability allows for further differentiation of habitat quality for red squirrels
and therefore for a refined estimation of the carrying capacity that was used to
inform population viability analysis (PVA) at Abernethy Forest. PVA assists the
evaluation of the probability of a species population to become extinct over a
specified period of time, given a set of data on environmental conditions and species
characteristics. In this study, two scenarios were modelled in a PVA package
(VORTEX). For the first scenario (Basic) carrying capacity was calculated for the
whole forest, while for the second scenario (LiDAR) only Medium-to-High suitable
patches were considered. Results suggest a higher probability of extinction for the
LiDAR scenario (74%) than for the Basic scenario (55%). Overall the findings of this
study highlight 1) the importance of considering forest structure when managing
habitat for squirrel conservation and 2) the usefulness of LiDAR remote sensing as a
tool to assist red squirrel, and potentially other species, habitat management
Metodología de clasificación automática de uso y cobertura de suelo : Uso de métodos de aprendizaje automático y teledetección para clasificación de uso y cobertura del suelo en un valle semiárido de la Patagonia
El valle agrícola-ganadero en la Cuenca Inferior del Río Chubut (VIRCh) tiene una extensión de 225 km2 y está situado en la Patagonia semiárida oriental argentina. Si bien este es uno de los valles más importantes de la región no existe hasta ahora información espacial completa, detallada y actualizada de sus actividades y coberturas del suelo. En este artículo avanzamos en la sistematización de este proceso y comparamos 7 métodos tradicionales de aprendizaje automático supervisado aplicados a la clasificación del uso y la cobertura del suelo a partir de imágenes satelitales de Sentinel-2 MSI y de datos adquiridos sobre el terreno. Con estos métodos obtuvimos predicciones que superan entre el 70 y 80 % de precisión en la clasificación de cultivos frutales, horticultura, terrenos construidos, arbustales, pasturas y agua.
Nearest Neighbors y Decision Tree fueron los clasificadores que mostraron los mejores desempeños. El código fuente y algoritmos desarrollados están disponibles en: DOI: 10.5281/zenodo.5338597 para su libre recreación, uso y reproducibilidad.Sociedad Argentina de Informática e Investigación Operativ
Ecos de la tormenta de Comodoro Rivadavia en el valle inferior del Río Chubut. Aporte de sedimentos al Río Chubut desde la cuenca del Río Chico
El evento de abril de 2017 produjo en las comunidades del noreste de Chubut una crisis inusitada en la provisión de agua potable. Los sistemas de potabilización del agua, capaces de manejar los frecuentes eventos de turbiedad elevada producidos por precipitaciones torrenciales de corta duración sobre el Valle Inferior del Río Chubut, se vieron desbordados por un evento de características nuevas. La ?tormenta de Comodoro Rivadavia? fue de carácter extraordinario: 330 mm entre el 29 de marzo y el 4 de abril, con un máximo de 232 mm en 24 horas. La lluvia se extendió más allá de Comodoro Rivadavia abarcando el extremo sur de la cuenca del Río Chico. La conjunción de la lluvia y de la falta de vegetación en la cuenca (cerca del 62% de la superficie está desprovista de vegetación) produjo una crecida con caudal máximo estimado en 667 m3/s. El Río Chico es un afluente no permanente del DiqueFlorentino Ameghino. La crecida elevó el embalse en 12 m aproximadamente y aportó una cantidad ingente de sedimentos. La turbiedad alta en el embalse y en el Río Chubut se mantuvo por casi 60 días, lo que provocó cortes y restricciones al suministro de agua potable por tres meses, una duración y picos máximos de turbiedad nunca imaginados. El evento de abril de 2017 revela por sí mismo la complejidad y la fragilidad de la realidad hídrica de la comarca del VIRCH. Sequías, inundaciones, y problemas con la calidad del agua son problemas intrínsecos de las características biofísicas de este sistema, y sólo pueden ser agravados por el cambio climático y las actividades humanas no planificadas.Fil: Kaless, Gabriel. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Pascual, Miguel Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; ArgentinaFil: Flaherty, Silvia. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Liberoff, Ana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; ArgentinaFil: Garcia Asorey, Martin Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Brandizi, Laura Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Pessacg, Natalia Liz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; Argentin
Grupo técnico del comité de cuenca del río Chubut: Experiencia y aprendizajes
El objetivo de este trabajo es documentar y comunicar la experiencia y aprendizajes resultantes de la participación de los organismos de ciencia y técnica de la región, a través del Grupo Técnico del Comité de Cuenca del Río Chubut, en ámbitos de toma de decisión sobre la Cuenca del Río Chubut.Fil: Pessacg, Natalia Liz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; ArgentinaFil: Liberoff, Ana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; ArgentinaFil: Rimoldi, Pablo. Universidad del Chubut; ArgentinaFil: Salvadores, Franco José. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Diaz, Lucas. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Brandizi, Laura. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Alonso Roldán, Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; Argentina. Universidad Tecnológica Nacional. Facultad Regional Chubut; ArgentinaFil: Rius, Pía. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Kaless, Gabriel. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Flaherty, Silvia. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Hernández, Marcos. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Pascual, Miguel Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; ArgentinaXXVII Congreso Nacional del AguaBuenos AiresArgentinaInstituto Nacional del Agu
Acute exacerbation of idiopathic pulmonary fibrosis: International survey and call for harmonisation.
AIM
Acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) is an often deadly complication of IPF. No focused international guidelines for the management of AE-IPF exist. The aim of this international survey was to assess the global variability in prevention, diagnostic and treatment strategies for AE-IPF.
MATERIAL AND METHODS
Pulmonologists with ILD expertise were invited to participate in a survey designed by an international expert panel.
RESULTS
509 pulmonologists from 66 countries responded. Significant geographical variability in approaches to manage AE-IPF was found. Common preventive measures included antifibrotic drugs and vaccination. Diagnostic differences were most pronounced regarding use of KL-6 and viral testing, while HRCT, BNP and D-Dimer are generally applied. High dose steroids are widely administered (94%); the use of other immunosuppressant and treatment strategies is highly variable. Very few (4%) responders never use immunosuppression. Antifibrotic treatments are initiated during AE-IPF by 67%. Invasive ventilation or extracorporeal membrane oxygenation are mainly used as a bridge to transplantation. Most physicians educate patients comprehensively on the severity of AE-IPF (82%) and consider palliative care (64%).
CONCLUSION
Approaches to the prevention, diagnosis and treatment of AE-IPF vary worldwide. Global trials and guidelines to improve the prognosis of AE-IPF are needed
Integrating Clinical Probability into the Diagnostic Approach to Idiopathic Pulmonary Fibrosis: An International Working Group Perspective
Background. When considering the diagnosis of idiopathic pulmonary fibrosis (IPF), experienced
clinicians integrate clinical features that help to differentiate IPF from other fibrosing interstitial lung
diseases, thus generating a “pre-test” probability of IPF. The aim of this international working group
perspective was to summarize these features using a tabulated approach similar to chest HRCT and
histopathologic patterns reported in the international guidelines for the diagnosis of IPF, and to help
formally incorporate these clinical likelihoods into diagnostic reasoning to facilitate the diagnosis of
IPF.
Methods. The committee group identified factors that influence the clinical likelihood of a diagnosis
of IPF, which was categorized as a pre-test clinical probability of IPF into “high” (70-100%),
“intermediate” (30-70%), or “low” (0-30%). After integration of radiological and histopathological
features, the post-test probability of diagnosis was categorized into “definite” (90-100%), “high
confidence” (70-89%), “low confidence” (51-69%), or “low” (0-50%) probability of IPF.
Findings. A conceptual Bayesian framework was created, integrating the clinical likelihood of IPF
(“pre-test probability of IPF”) with the HRCT pattern, the histopathology pattern when available,
and/or the pattern of observed disease behavior into a “post-test probability of IPF”. The diagnostic
probability of IPF was expressed using an adapted diagnostic ontology for fibrotic interstitial lung
diseases.
Interpretation. The present approach will help incorporate the clinical judgement into the diagnosis
of IPF, thus facilitating the application of IPF diagnostic guidelines and, ultimately improving
diagnostic confidence and reducing the need for invasive diagnostic techniques
Benchmarking of Mutation Diagnostics in Clinical Lung Cancer Specimens
Treatment of EGFR-mutant non-small cell lung cancer patients with the tyrosine kinase inhibitors erlotinib or gefitinib results in high response rates and prolonged progression-free survival. Despite the development of sensitive mutation detection approaches, a thorough validation of these in a clinical setting has so far been lacking. We performed, in a clinical setting, a systematic validation of dideoxy ‘Sanger’ sequencing and pyrosequencing against massively parallel sequencing as one of the most sensitive mutation detection technologies available. Mutational annotation of clinical lung tumor samples revealed that of all patients with a confirmed response to EGFR inhibition, only massively parallel sequencing detected all relevant mutations. By contrast, dideoxy sequencing missed four responders and pyrosequencing missed two responders, indicating a dramatic lack of sensitivity of dideoxy sequencing, which is widely applied for this purpose. Furthermore, precise quantification of mutant alleles revealed a low correlation (r2 = 0.27) of histopathological estimates of tumor content and frequency of mutant alleles, thereby questioning the use of histopathology for stratification of specimens for individual analytical procedures. Our results suggest that enhanced analytical sensitivity is critically required to correctly identify patients responding to EGFR inhibition. More broadly, our results emphasize the need for thorough evaluation of all mutation detection approaches against massively parallel sequencing as a prerequisite for any clinical implementation
Para-infectious brain injury in COVID-19 persists at follow-up despite attenuated cytokine and autoantibody responses
To understand neurological complications of COVID-19 better both acutely and for recovery, we measured markers of brain injury, inflammatory mediators, and autoantibodies in 203 hospitalised participants; 111 with acute sera (1–11 days post-admission) and 92 convalescent sera (56 with COVID-19-associated neurological diagnoses). Here we show that compared to 60 uninfected controls, tTau, GFAP, NfL, and UCH-L1 are increased with COVID-19 infection at acute timepoints and NfL and GFAP are significantly higher in participants with neurological complications. Inflammatory mediators (IL-6, IL-12p40, HGF, M-CSF, CCL2, and IL-1RA) are associated with both altered consciousness and markers of brain injury. Autoantibodies are more common in COVID-19 than controls and some (including against MYL7, UCH-L1, and GRIN3B) are more frequent with altered consciousness. Additionally, convalescent participants with neurological complications show elevated GFAP and NfL, unrelated to attenuated systemic inflammatory mediators and to autoantibody responses. Overall, neurological complications of COVID-19 are associated with evidence of neuroglial injury in both acute and late disease and these correlate with dysregulated innate and adaptive immune responses acutely
Adding 6 months of androgen deprivation therapy to postoperative radiotherapy for prostate cancer: a comparison of short-course versus no androgen deprivation therapy in the RADICALS-HD randomised controlled trial
Background
Previous evidence indicates that adjuvant, short-course androgen deprivation therapy (ADT) improves metastasis-free survival when given with primary radiotherapy for intermediate-risk and high-risk localised prostate cancer. However, the value of ADT with postoperative radiotherapy after radical prostatectomy is unclear.
Methods
RADICALS-HD was an international randomised controlled trial to test the efficacy of ADT used in combination with postoperative radiotherapy for prostate cancer. Key eligibility criteria were indication for radiotherapy after radical prostatectomy for prostate cancer, prostate-specific antigen less than 5 ng/mL, absence of metastatic disease, and written consent. Participants were randomly assigned (1:1) to radiotherapy alone (no ADT) or radiotherapy with 6 months of ADT (short-course ADT), using monthly subcutaneous gonadotropin-releasing hormone analogue injections, daily oral bicalutamide monotherapy 150 mg, or monthly subcutaneous degarelix. Randomisation was done centrally through minimisation with a random element, stratified by Gleason score, positive margins, radiotherapy timing, planned radiotherapy schedule, and planned type of ADT, in a computerised system. The allocated treatment was not masked. The primary outcome measure was metastasis-free survival, defined as distant metastasis arising from prostate cancer or death from any cause. Standard survival analysis methods were used, accounting for randomisation stratification factors. The trial had 80% power with two-sided α of 5% to detect an absolute increase in 10-year metastasis-free survival from 80% to 86% (hazard ratio [HR] 0·67). Analyses followed the intention-to-treat principle. The trial is registered with the ISRCTN registry, ISRCTN40814031, and ClinicalTrials.gov, NCT00541047.
Findings
Between Nov 22, 2007, and June 29, 2015, 1480 patients (median age 66 years [IQR 61–69]) were randomly assigned to receive no ADT (n=737) or short-course ADT (n=743) in addition to postoperative radiotherapy at 121 centres in Canada, Denmark, Ireland, and the UK. With a median follow-up of 9·0 years (IQR 7·1–10·1), metastasis-free survival events were reported for 268 participants (142 in the no ADT group and 126 in the short-course ADT group; HR 0·886 [95% CI 0·688–1·140], p=0·35). 10-year metastasis-free survival was 79·2% (95% CI 75·4–82·5) in the no ADT group and 80·4% (76·6–83·6) in the short-course ADT group. Toxicity of grade 3 or higher was reported for 121 (17%) of 737 participants in the no ADT group and 100 (14%) of 743 in the short-course ADT group (p=0·15), with no treatment-related deaths.
Interpretation
Metastatic disease is uncommon following postoperative bed radiotherapy after radical prostatectomy. Adding 6 months of ADT to this radiotherapy did not improve metastasis-free survival compared with no ADT. These findings do not support the use of short-course ADT with postoperative radiotherapy in this patient population
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