Modeling the coupled dynamics of stream metabolism and microbial biomass

Estimating and interpreting ecosystem metabolism remains an important challenge in stream ecology. Here, we propose a novel approach to model, estimate, and predict multiseasonal patterns of stream metabolism (gross primary production [GPP] and ecosystem respiration [ER]) at the reach scale leveraging on increasingly available long-term, high-frequency measurements of dissolved oxygen (DO). The model uses DO measurements to estimate the parameters of a simple ecosystem model describing the underlying dynamics of stream autotrophic and heterotrophic microbial biomass. The model has been applied to four reaches within the Ybbs river network, Austria. Even if microbial biomasses are not observed, that is, they are treated as latent variables, results show that by accounting for the temporal dynamics of biomass, the model reproduces variability in metabolic fluxes that is not explained by fluctuations of light, temperature, and resources. The model is particularly data-demanding: to estimate the 11 parameters used in this formulation, it requires sufficiently long, for example, annual, time series, and significant scouring events. On the other hand, the approach has the potential to separate ER into its autotrophic and heterotrophic components, estimate a richer set of ecosystem carbon fluxes (i.e., carbon uptake, loss, and scouring), extrapolate metabolism estimates for periods when DO measurements are unavailable, and predict how ecosystem metabolism would respond to variations of the driving forces. The model is seen as a building block to develop tools to fully appreciate multiseasonal patterns of metabolic activity in river networks and to provide reliable estimations of carbon fluxes from land to ocean

The Metabolic Regimes at the Scale of an Entire Stream Network Unveiled Through Sensor Data and Machine Learning

Streams and rivers form dense networks that drain the terrestrial landscape and are relevant for biodiversity dynamics, ecosystem functioning, and transport and transformation of carbon. Yet, resolving in both space and time gross primary production (GPP), ecosystem respiration (ER) and net ecosystem production (NEP) at the scale of entire stream networks has been elusive so far. Here, combining Random Forest (RF) with time series of sensor data in 12 reach sites, we predicted annual regimes of GPP, ER, and NEP in 292 individual stream reaches and disclosed properties emerging from the network they form. We further predicted available light and thermal regimes for the entire network and expanded the library of stream metabolism predictors. We found that the annual network-scale metabolism was heterotrophic yet with a clear peak of autotrophy in spring. In agreement with the River Continuum Concept, small headwaters and larger downstream reaches contributed 16% and 60%, respectively, to the annual network-scale GPP. Our results suggest that ER rather than GPP drives the metabolic stability at the network scale, which is likely attributable to the buffering function of the streambed for ER, while GPP is more susceptible to flow-induced disturbance and fluctuations in light availability. Furthermore, we found large terrestrial subsidies fueling ER, pointing to an unexpectedly high network-scale level of heterotrophy, otherwise masked by simply considering reach-scale NEP estimations. Our machine learning approach sheds new light on the spatiotemporal dynamics of ecosystem metabolism at the network scale, which is a prerequisite to integrate aquatic and terrestrial carbon cycling at relevant scales

Partição de matéria seca da parte aérea em arroz para uso em um modelo de simulação baseado em processos.

A partição as matéria seca nos diversos compartimentos da planta é uma parte importante em modelos ecofisiológicos baseados em processos, com o InfoCrop. O objetivo deste trabalho foi determinar a fração da matéria seca da parte aérea alocada nos diferentes compartimentos da planta de arroz e a senescência ao longo do ciclo de desenvolvimento da cultura. Foi conduzido um experimento de campo em Santa Maria, RS, com quatro cultivares (IRGA 421, BRS Querência, IRGA 424 e BRS Tio Taka) e semeadura em 18/11/2011. A fração da matéria seca da parte aérea alocada nos diferentes compartimentos da planta e a senescência variou em função do estágio de desenvolvimento, desde 80% para folhas nos primeiros quatro dias após a emergência até 100% para panículas após floração

Obtaining high purity silica from rice hulls

Many routes for extracting silica from rice hulls are based on direct calcining. These methods, though, often produce silica contaminated with inorganic impurities. This work presents the study of a strategy for obtaining silica from rice hulls with a purity level adequate for applications in electronics. The technique is based on two leaching steps, using respectively aqua regia and Piranha solutions, which extract the organic matrix and inorganic impurities. The material was characterized by Fourier-transform infrared spectroscopy (FTIR), powder x-ray diffraction (XRD), x-ray fluorescence (XRF), scanning electron microscopy (SEM), particle size analysis by laser diffraction (LPSA) and thermal analysis

Loss of the extracellular matrix glycoprotein EMILIN1 accelerates Δ16HER2-driven breast cancer initiation in mice

The extracellular matrix (ECM) is an important component of the tumor microenvironment and undergoes extensive remodeling during both initiation and progression of breast cancer (BC). EMILIN1 is an ECM glycoprotein, whose function has been linked to cancer and metastasis. However, EMILIN1 role during mammary gland and BC development has never been investigated. In silico and molecular analyses of human samples from normal mammary gland and BC showed that EMILIN1 expression was lower in tumors than in healthy mammary tissue and it predicted poor prognosis, particularly in HER2-positive BC. HER2+ BC accounts for 15-20% of all invasive BC and is characterized by high aggressiveness and poor prognosis. The Δ16HER2 isoform, a splice variant with very high oncogenic potential, is frequently expressed in HER2+ BC and correlates with metastatic disease. To elucidate the role of EMILIN1 in BC, we analyzed the phenotype of MMTV-Δ16HER2 transgenic mice, developing spontaneous multifocal mammary adenocarcinomas, crossed with EMILIN1 knock-out (KO) animals. We observed that Δ16HER2/EMILIN1 KO female mice exhibited an accelerated normal mammary gland development and a significantly anticipated appearance of palpable tumors (13.32 vs 15.28 weeks). This accelerated tumor initiation was corroborated by an increased number of tumor foci observed in mammary glands from Δ16HER2/EMILIN1 KO mice compared to the wild-type counterpart. Altogether our results underscore the centrality of ECM in the process of BC initiation and point to a role for EMILIN1 during normal mammary gland development and in protecting from HER2-driven breast tumorigenesis

Formulation study of quercetin-loaded lipid-based nanocarriers obtained by hot solvent diffusion method

Lipid-based nanocarriers were prepared by hot solvent diffusion technique. Tristearin (TS) and/or castor oil were employed as oily phase, and Lutrol F68® or Solutol HS15® and lecithin were employed as surfactant and cosurfactant, respectively. The influence of the formulation variables on surface charge and size of the nanocarriers and their ability to load and control the release of quercetin were investigated. Solid lipid nanoparticles, nanostructured lipid carriers, nanoemulsions, and microemulsions (ME) were obtained depending on the formulation composition. Querecetin (QU) entrapment efficacy was higher than 99 % for all formulations. However, drug content was greatly affected by the formulation composition. ME exhibited the highest capacity to load QU, reaching a concentration around 1,300 times higher than its aqueous solubility. QU release profiles exhibited biphasic kinetics for all formulations. However, the release rate of QU was affected by the properties of the nanocarrier.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Current and novel therapeutic opportunities for systemic therapy in biliary cancer

none24Biliary tract cancers (BTCs) are a group of rare and aggressive malignancies that arise in the biliary tree within and outside the liver. Beyond surgical resection, which is beneficial for only a small proportion of patients, current strategies for treating patients with BTCs include chemotherapy, as a single agent or combination regimens, in the adjuvant and palliative setting. Increased characterisation of the molecular landscape of these tumours has facilitated the identification of molecular vulnerabilities, such as IDH mutations and FGFR fusions, that can be exploited for the treatment of BTC patients. Beyond targeted therapies, active research avenues explore the development of novel therapeutics that target the crosstalk between cancer and stroma, the cellular pathways involved in the regulation of cell death, the chemoresistance phenotype and the dysregulation of RNA. In this review, we discuss the therapeutic opportunities currently available in the management of BTC patients, and explore the strategies that can support the implementation of precision oncology in BTCs, including novel molecular targets, liquid biopsies and patient-derived predictive tools.openMarin J.J.G.; Prete M.G.; Lamarca A.; Tavolari S.; Landa-Magdalena A.; Brandi G.; Segatto O.; Vogel A.; Macias R.I.R.; Rodrigues P.M.; Casta A.L.; Mertens J.; Rodrigues C.M.P.; Fernandez-Barrena M.G.; Da Silva Ruivo A.; Marzioni M.; Mentrasti G.; Acedo P.; Munoz-Garrido P.; Cardinale V.; Banales J.M.; Valle J.W.; Bridgewater J.; Braconi C.Marin, J. J. G.; Prete, M. G.; Lamarca, A.; Tavolari, S.; Landa-Magdalena, A.; Brandi, G.; Segatto, O.; Vogel, A.; Macias, R. I. R.; Rodrigues, P. M.; Casta, A. L.; Mertens, J.; Rodrigues, C. M. P.; Fernandez-Barrena, M. G.; Da Silva Ruivo, A.; Marzioni, M.; Mentrasti, G.; Acedo, P.; Munoz-Garrido, P.; Cardinale, V.; Banales, J. M.; Valle, J. W.; Bridgewater, J.; Braconi, C

Giant Cell Arteritis Presenting as Small Bowel Infarction

Giant cell arteritis predominantly affects cranial arteries and rarely involves other sites. We report a patient who presented with small bowel obstruction because of infarction from mesenteric giant cell arteritis. She had an unusual cause of her obstruction and a rare manifestation of giant cell arteritis. In spite of aggressive therapy with steroids, she died a month later because of multiple complications. We discuss the diagnosis and management of small bowel obstruction and differential diagnosis of vasculitis of the gastrointestinal tract. We were able to find 11 cases of bowel involvement with giant cell arteritis in the English literature. This case report illustrates that giant cell arteritis can be a cause of small bowel obstruction and bowel infarction. In the proper clinical setting, vasculitides need to be considered early in the differential diagnosis when therapy may be most effective