How similar can co-occurring species be in the presence of competition and ecological drift?

If two species live on a single resource, the one with a slight advantage will out-compete the other: complete competitors cannot coexist. This is known as the competitive exclusion principle. If no extinction occurs, it is because evolutionary adaptation to slightly different niches takes place. Therefore, it is widely accepted that ecological communities are assembled by evolutionary differentiation and progressive adaptation of species to different niches. However, some ecologists have recently challenged this classic paradigm highlighting the importance of chance and stochasticity. Using a synthetic framework for community dynamics, here we show that, while deterministic descriptors predict coexistence, species similarity is limited in a more restrictive way in the presence of stochasticity. We analyse the stochastic extinction phenomenon, showing that extinction occurs as competitive overlap increases above a certain threshold well below its deterministic counterpart. We also prove that the extinction threshold cannot be ascribed only to demographic fluctuations around small population sizes. The more restrictive limit to species similarity is, therefore, a consequence of the complex interplay between competitive interactions and ecological drift. As a practical implication, we show that the existence of a stochastic limit to similarity has important consequences in the recovery of fragmented habitats

A signal of competitive dominance in mid-latitude herbaceous plant communities

Understanding the main determinants of species coexistence across space and time is a central question in ecology. However, ecologists still know little about the scales and conditions at which biotic interactions matter and how these interact with the environment to structure species assemblages. Here we use recent theoretical developments to analyse plant distribution and trait data across Europe and find that plant height clustering is related to both evapotranspiration (ET) and gross primary productivity. This clustering is a signal of interspecies competition between plants, which is most evident in mid-latitude ecoregions, where conditions for growth (reflected in actual ET rates and gross primary productivities) are optimal. Away from this optimum, climate severity probably overrides the effect of competition, or other interactions become increasingly important. Our approach bridges the gap between species-rich competition theories and large-scale species distribution data analysisThis work was funded by the Spanish ‘Ministerio de Economía y Competitividad’ under the projects CGL2012-39964 and CGL2015-69043-P (D.A. and J.A.C.), by the Spanish ‘Ministerio de Ciencia, Innovación y Universidades’ under the project PGC2018-096577-B-I00 (D.A. and J.A.C.), and the Ramón y Cajal Fellowship program (RYC-2010-06545, D.A.). J.A.C. acknowledges partial financial support from the Department of Applied Mathematics (Universidad Politécnica de Madrid). S.C. acknowledges financial support from Banco Santander through grant no. PR87/19-2258

Fibropapilomatosis oral múltiple como manifestación inicial de Síndrome de Cowden: caso clínico

El síndrome de Cowden es una infrecuente enfermedad hereditaria englobada dentro de las poliposis gastrointestinales de tipo hamartomatoso. Se caracteriza por asociar anomalías cutaneomucosas y por la extraordinaria tendencia a desarrollar neoplasias malignas, principalmente de mama y tiroides. La importancia de un diagnóstico precoz del síndrome y de un adecuado screening tumoral en pacientes con lesiones papilomatosas cutaneomucosas, nos va a permitir adelantarnos en el diagnóstico de patologías con enorme morbimortalidad asociada en caso de una detección tardía. Presentamos el caso de una paciente diagnosticada de síndrome de Cowden tras consultar por lesiones papilomatosas labiales de largo tiempo de evolución y tratada posteriormente de cáncer de mama y riñón en estadios iniciales. El correcto diagnóstico de una patología banal de mucosa oral, nos ha permitido actuar de manera muy precoz frente a la patología neoplásica asociada a dicha enfermedad.Cowden syndrome is a rare hereditary disease included within hamartoma-type gastrointestinal polyposis. It is characterised by associated mucocutaneous anomalies and by the extraordinary tendency to develop malignant neoplasia, mainly in the breast and thyroid. Early diagnosis of the syndrome and adequate tumoral screening in patients with mucocutaneous papillomatosis make it possible to make an earlier diagnosis of associated pathologies which have great morbidity when detected late. We present the case of a patient diagnosed with Cowden syndrome after consultation for labial papillomatous lesions of long evolution who was subsequently treated for breast and kidney cancer in initial stages. The correct diagnosis of a banal pathology of oral mucosa made it possible for us to take early action against the neoplastic pathology associated with this disease

Prognostic value of circulating microRNAs in upper tract urinary carcinoma

The identification of upper tract urinary carcinoma (UTUC) prognostic biomarkers is urgently needed to predict tumour progression. This study aimed to identify serum microRNAs (miRNAs) that may be useful as minimally invasive predictive biomarkers of tumour progression and survival in UTUC patients. To this end, 33 UTUC patients who underwent radical nephroureterectomy at the Hospital Clinic of Barcelona were prospectively included. Expression of 800 miRNAs was evaluated in serum samples from these patients using nCounter® miRNA Expression Assays. The study was divided into an initial discovery phase (n=12) and a validation phase (n=21). Cox regression analysis was used for survival analysis. The median follow-up (range) of the series was 42 months (9-100 months). In the discovery phase, 38 differentially expressed miRNAs were identified between progressing and non-progressing UTUC patients (p<0.05). Validation of these 38 miRNAs in an independent set of UTUC patients confirmed the differential expression in 18 of them (p<0.05). Cox Regression analysis showed miR-151b and pathological stage as significant prognostic factors for tumour progression (HR=0.33, p<0.001 and HR=2.62, p=0.006, respectively) and cancer specific survival (HR=0.25, p<0.001 and HR=3.98, p=0.003, respectively). Survival curves revealed that miR-151b is able to discriminate between two groups of UTUC patients with a highly significant different probability of tumour progression (p=0.006) and cancer specific survival (p=0.034). Although the data needs to be externally validated, miRNA analysis in serum appears to be a valuable prognostic tool in UTUC patients. Particularly, differential expression of miR-151b in serum may serve as a minimally invasive prognostic tool in UTUC

Multiple oral fibropapillomatosis as an initial manifestation of Cowden Syndrome : case report

El síndrome de Cowden es una infrecuente enfermedad hereditaria englobada dentro de las poliposis gastrointestinales de tipo hamartomatoso. Se caracteriza por asociar anomalías cutaneomucosas y por la extraordinaria tendencia a desarrollar neoplasias malignas, principalmente de mama y tiroides. La importancia de un diagnóstico precoz del síndrome y de un adecuado screening tumoral en pacientes con lesiones papilomatosas cutaneomucosas, nos va a permitir adelantarnos en el diagnóstico de patologías con enorme morbimortalidad asociada en caso de una detección tardía. Presentamos el caso de una paciente diagnosticada de síndrome de Cowden tras consultar por lesiones papilomatosas labiales de largo tiempo de evolución y tratada posteriormente de cáncer de mama y riñón en estadios iniciales. El correcto diagnóstico de una patología banal de mucosa oral, nos ha permitido actuar de manera muy precoz frente a la patología neoplásica asociada a dicha enfermedad

Capillary microfluidic platform for sulfite determination in wines

A microfluidic paper-based analytical device integrating a chromoreactand – a formylazo dye– has been fabri- cated and used for a colorimetric assay of sulfites. The chromoreactand was covalently linked to paper by vinyl sulfone chemistry. This work presents two robust capillary microfluidic devices to determine sulfite in wine without any pretreatment. One of them based on thread (µTPAD) useful to determine it in white wine and another based on paper (µPAD) to specifically determine sulfite in red wine as well as in white wine. Both are based on the selective recognition of sulfite by means of a chromoreactand that turns from orange to yellow in the presence of sulfite. The colour information acquired (H coordinate) using a digital camera readout allows for a range of appli- cation of the µTPAD from 7.8⋅10−5 M (8.1 mg L−1) to 2.7⋅10−3 M (279.3 mg L−1) with a limit of detection (LOD) of 78 µM. The strong interference caused by the dyes present in red wine is eliminated by including a laminated paper channel in the µPAD structure that allows for the separation of colorants from red wine before the recognition of the sulfite. This makes it possible to adjust the µPAD procedure to the usual sulfite concentration in wine, with an LOD of 2.2⋅10−4 M (22.7 mg L−1) and a CV of 2.6%.This work was founded by Spanish “Ministerio de Economía y Competitividad” (Projects PID2019-103938RB-I00) and Junta de Andalucía (Projects B-FQM-243-UGR18 and P18-RT-2961). The projects were partially supported by European Regional Development Funds (ERDF)

Tutorización británica combinada con TIC y evaluación por rúbrica

Memoria ID-083. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2013-2014

Src-Homology 2 Domain-Containing Phosphatase 2 in Resected EGFR Mutation-Positive Lung Adenocarcinoma

Funding: supported by a La Caixa Foundation grant and the Spanish Association Against Cancer (PROYE18012ROSE)EGFR mutation-positive lung adenocarcinoma (LUAD) displays impaired phosphorylation of ERK and Src-homology 2 domain-containing phosphatase 2 (SHP2) in comparison with EGFR wild-type LUADs. We hypothesize that SHP2 expression could be predictive in patients positive with resected EGFR mutation versus patients with EGFR wild-type LUAD. We examined resected LUAD cases from Japan and Spain. mRNA expression levels of AXL, MET, CDCP1, STAT3, YAP1, and SHP2 were analyzed by quantitative reverse transcriptase polymerase chain reaction. The activity of SHP2 inhibitors plus erlotinib were tested in EGFR -mutant cell lines and analyzed by cell viability assay, Western blot, and immunofluorescence. A total of 50 of 100 EGFR mutation-positive LUADs relapsed, among them, patients with higher SHP2 mRNA expression revealed shorter progression-free survival, in comparison with those having low SHP2 mRNA (hazard ratio: 1.83; 95% confidence interval: 1.05-3.23; p = 0.0329). However, SHP2 was not associated with prognosis in the remaining 167 patients with wild-type EGFR. In EGFR -mutant cell lines, the combination of SHP099 or RMC-4550 (SHP2 inhibitors) with erlotinib revealed synergism via abrogation of phosphorylated AKT (S473) and ERK1/2 (T202/Y204). Although erlotinib translocates phosphorylated SHP2 (Y542) into the nucleus, either RMC-4550 alone, or in combination with erlotinib, relocates SHP2 into the cytoplasm membrane, limiting AKT and ERK1/2 activation. Elevated SHP2 mRNA levels are associated with recurrence in resected EGFR mutation-positive LUADs, but not in EGFR wild-type. EGFR tyrosine kinase inhibitors can enhance SHP2 activation, hindering adjuvant therapy. SHP2 inhibitors could improve the benefit of adjuvant therapy in EGFR mutation-positive LUADs

Tutorización Británica para química orgánica III. Del minigrupo al grupo

Memoria ID12-0171. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2012-2013

Improving Uncertainty Estimation With Semi-supervised Deep Learning for COVID-19 Detection Using Chest X-ray Images

In this work we implement a COVID-19 infection detection system based on chest Xray images with uncertainty estimation. Uncertainty estimation is vital for safe usage of computer aided diagnosis tools in medical applications. Model estimations with high uncertainty should be carefully analyzed by a trained radiologist. We aim to improve uncertainty estimations using unlabelled data through the MixMatch semi-supervised framework. We test popular uncertainty estimation approaches, comprising Softmax scores, Monte-Carlo dropout and deterministic uncertainty quantification. To compare the reliability of the uncertainty estimates, we propose the usage of the Jensen-Shannon distance between the uncertainty distributions of correct and incorrect estimations. This metric is statistically relevant, unlike most previously used metrics, which often ignore the distribution of the uncertainty estimations. Our test results show a significant improvement in uncertainty estimates when using unlabelled data. The best results are obtained with the use of the Monte Carlo dropout method