Uterine Adenocarcinoma in pet rabbits: a review

The uterine adenocarcinoma is a slow growing malignant tumour that affects 50-80% of pet rabbits over 4 years old, having age as its major risk factor. The mechanisms underlying the development of this tumour are not completely understood and some of the existing studies presented contradictory results. In fact, in rabbits there is not an adequate classification of these tumours and until now the cellular and molecular features were not fully investigated. Regarding treatment and until today, ovariohysterectomy is the only effective treatment. Without it, this neoplasia leads to the female rabbit’s death within 1 to 2 years after the appearance of symptoms and metastasis. In spite of the fact that these tumours could in other species be treated by chemotherapy, radiotherapy and hormonal therapy, in rabbits these treatments were mainly used in laboratory animals and therefore, there is no data regarding the adequate protocol. The limited studies available and the existing doubts around the development of the uterine adenocarcinoma in rabbits show that further investigation is necessary to provide other ways to make an accurate diagnosis, to establish an adequate treatment protocol and to determine the prognosis.O adenocarcinoma uterino é um tumor maligno de crescimento lento que afecta 50-80% dos coelhos com mais de 4 anos, sendo a idade o principal factor de risco para esta neoplasia. Os mecanismos que envolvem o desenvolvimento deste tumor não estão totalmente clarificados e alguns estudos apresentam resultados contraditórios. Actualmente, a classificação bem como a caracterização celular e molecular do adenocarcinoma uterino nesta espécie permanece pouco aprofundada. Até à data, a ovariohisterectomia é o único tratamento eficaz e, na sua ausência, o adenocarcinoma provoca a morte num período de 1 a 2 anos após o aparecimento de sintomas e metástases. Em diferentes espécies, a quimioterapia, a radioterapia e a terapia hormonal são outras opções de tratamento, no entanto nos coelhos a sua aplicação é apenas experimental e associada a animais de biotério, não existindo informação suficiente para o estabelecimento de protocolos adequados à espécie. O número limitado de estudos e as permanentes dúvidas associadas ao desenvolvimento desta patologia em coelhos evidencia a necessidade de investimento na investigação, a qual poderá revelar novas formas de diagnóstico e tratamento e, consequentemente, alterar o prognóstico

Identifying critical thresholds to guide management practices in agroecosystems: Insights from bird community response to an open grassland-to-forest gradient

Landscapes are showing increased fragmentation and habitat loss due to land-use conversion and intensification, leading to species-poor and homogeneous communities. The identification of ecological thresholds above which major changes in community composition take place, may prevent the critical downfall of biodiversity while improving the effectiveness of conservation, resource management and restoration practices. In this study, we provide a new insight on how species distribute along a highly variegated agro-ecosystem in the Mediterranean region. We aim to define the thresholds of occurrence of a bird community inhabiting a tree canopy gradient, and determine the patterns of community change. We fit Huisman-Olff-Fresco models to bird occurrence data (assuming non-linear responses) to identify species-specific responses to the gradient, species richness, and turnover patterns. The tree canopy gradient is responsible for major changes in bird community likely related to the variation of the tree stratum and canopy enclosure which reflect different niche segregation opportunities. Maximum species richness was reached at 10% canopy cover while total turnover rate was higher than expected from a null model up to 10% canopy cover. Ecological thresholds can be used as indicators of specific resource limits responsible for changes in community composition and species occurrence, identifying where populations may be more sensitive. Choosing a single management scheme will invariably result in winners and losers, but optimal levels of management can be explored in order to maximize species diversity across Mediterranean agroecosystems

Magnetic phase transitions in Gd64Sc36 studied using non-contact ultrasonics

The speed and attenuation of ultrasound propagation can be used to determine material properties and identify phase transitions. Standard ultrasonic contact techniques are not always convenient due to the necessity of using couplant; however, recently reliable non-contact ultrasonic techniques involving electromagnetic generation and detection of ultrasound with electromagnetic acoustic transducers (EMATs) have been developed for use on electrically conducting and/or magnetic materials. We present a detailed study of magnetic phase transitions in a single crystal sample of Gd64Sc36 magnetic alloy using contact and non-contact ultrasonic techniques for two orientations of external magnetic field. Phase diagrams are constructed based on measurements of elastic constant C33, the attenuation and the efficiency of generation when using an EMAT. The EMATs are shown to provide additional information related to the magnetic phase transitions in the studied sample, and results identify a conical helix phase in Gd64Sc36 in the magnetic field orientation

Differential response to dexamethasone on the TXB2 release in guinea-pig alveolar macrophages induced by zymosan and cytokines

Glucocorticosteroids reduce the production of inflammatory mediators but this effect may depend on the stimulus. We have compared the time course of the effect of dexamethasone on the thromboxane B2 (TXB2) release induced by cytokine stimulation and zymosan in guinea-pig alveolar macrophages. Interleukin-1β (IL-1β), tumour necrosis factor-α (TNF-α) and opsonized zymosan (OZ), all stimulate TXB2 release. High concentrations of dexamethasone (1–10 μM) inhibit the TXB2 production induced by both cytokines and OZ, but the time course of this response is different. Four hours of incubation with dexamethasone reduce the basal TXB2 release and that induced by IL-1β and TNF-α, but do not modify the TXB2 release induced by OZ. However, this stimulus was reduced after 24 h incubation. Our results suggest that the antiinflammatory activity of glucocorticosteroids shows some dependence on stimulus and, therefore, may have more than one mechanism involved

Quasi-static Flow Model for Predicting the Extreme Values of Air Pocket Pressure in Draining and Filling Operations in Single Water Installations

[EN] Inertial models have been used by researchers to simulate the draining and filling processes in water pipelines, based on the evolution of the main hydraulic and thermodynamic variables. These models use complex differential equations, which are solved using advanced numerical codes. In this study, a quasi-static flow model is developed to study these operations in hydraulic installations. The quasi-static flow model represents a simplified formulation compared with inertial flow models, in which its numerical resolution is easier because only algebraic equations must be addressed. Experimental measurements of air pocket pressure patterns were conducted in a 4.36 m long single pipeline with an internal diameter of 42 mm. Comparisons between measured and computed air pocket pressure oscillations indicate how the quasi-static flow model can predict extreme values of air pocket pressure for experimental runs, demonstrating the possibility of selecting stiffness and pipe classes in actual pipelines using this model. Two case studies were analysed to determine the behaviour of the quasi-static flow model in large water pipelines.This research and the APC were funded by the Comision Nacional de Investigacion Cientifica y Tecnologica (Conicyt), grant number 1180660.Coronado-Hernández, ÓE.; Fuertes-Miquel, VS.; Mora-Meliá, D.; Salgueiro, Y. (2020). Quasi-static Flow Model for Predicting the Extreme Values of Air Pocket Pressure in Draining and Filling Operations in Single Water Installations. Water. 12(3):1-16. https://doi.org/10.3390/w12030664S116123Abreu, J., Cabrera, E., Izquierdo, J., & García-Serra, J. (1999). Flow Modeling in Pressurized Systems Revisited. Journal of Hydraulic Engineering, 125(11), 1154-1169. doi:10.1061/(asce)0733-9429(1999)125:11(1154)Izquierdo, J., Fuertes, V. S., Cabrera, E., Iglesias, P. L., & Garcia-Serra, J. (1999). Pipeline start-up with entrapped air. Journal of Hydraulic Research, 37(5), 579-590. doi:10.1080/00221689909498518Simpson, A. R., & Wylie, E. B. (1991). Large Water‐Hammer Pressures for Column Separation in Pipelines. Journal of Hydraulic Engineering, 117(10), 1310-1316. doi:10.1061/(asce)0733-9429(1991)117:10(1310)Zhou, L., Liu, D., Karney, B., & Wang, P. (2013). Phenomenon of White Mist in Pipelines Rapidly Filling with Water with Entrapped Air Pockets. Journal of Hydraulic Engineering, 139(10), 1041-1051. doi:10.1061/(asce)hy.1943-7900.0000765Zhou, L., & Liu, D. (2013). Experimental investigation of entrapped air pocket in a partially full water pipe. Journal of Hydraulic Research, 51(4), 469-474. doi:10.1080/00221686.2013.785985Coronado-Hernández, O., Fuertes-Miquel, V., Besharat, M., & Ramos, H. (2017). Experimental and Numerical Analysis of a Water Emptying Pipeline Using Different Air Valves. Water, 9(2), 98. doi:10.3390/w9020098Coronado-Hernández, Ó. E., Besharat, M., Fuertes-Miquel, V. S., & Ramos, H. M. (2019). Effect of a Commercial Air Valve on the Rapid Filling of a Single Pipeline: a Numerical and Experimental Analysis. Water, 11(9), 1814. doi:10.3390/w11091814Vasconcelos, J. G., & Wright, S. J. (2008). Rapid Flow Startup in Filled Horizontal Pipelines. Journal of Hydraulic Engineering, 134(7), 984-992. doi:10.1061/(asce)0733-9429(2008)134:7(984)Fuertes-Miquel, V. S., Coronado-Hernández, O. E., Iglesias-Rey, P. L., & Mora-Meliá, D. (2018). Transient phenomena during the emptying process of a single pipe with water–air interaction. Journal of Hydraulic Research, 57(3), 318-326. doi:10.1080/00221686.2018.1492465Fuertes-Miquel, V. S., Coronado-Hernández, O. E., Mora-Meliá, D., & Iglesias-Rey, P. L. (2019). Hydraulic modeling during filling and emptying processes in pressurized pipelines: a literature review. Urban Water Journal, 16(4), 299-311. doi:10.1080/1573062x.2019.1669188Besharat, M., Coronado-Hernández, O. E., Fuertes-Miquel, V. S., Viseu, M. T., & Ramos, H. M. (2018). Backflow air and pressure analysis in emptying a pipeline containing an entrapped air pocket. Urban Water Journal, 15(8), 769-779. doi:10.1080/1573062x.2018.1540711Besharat, M., Coronado-Hernández, O. E., Fuertes-Miquel, V. S., Viseu, M. T., & Ramos, H. M. (2019). Computational fluid dynamics for sub-atmospheric pressure analysis in pipe drainage. Journal of Hydraulic Research, 58(4), 553-565. doi:10.1080/00221686.2019.1625819Laanearu, J., Annus, I., Koppel, T., Bergant, A., Vučković, S., Hou, Q., … van’t Westende, J. M. C. (2012). Emptying of Large-Scale Pipeline by Pressurized Air. Journal of Hydraulic Engineering, 138(12), 1090-1100. doi:10.1061/(asce)hy.1943-7900.0000631Tijsseling, A. S., Hou, Q., Bozkuş, Z., & Laanearu, J. (2015). Improved One-Dimensional Models for Rapid Emptying and Filling of Pipelines. Journal of Pressure Vessel Technology, 138(3). doi:10.1115/1.4031508Malekpour, A., Karney, B. W., & Nault, J. (2016). Physical Understanding of Sudden Pressurization of Pipe Systems with Entrapped Air: Energy Auditing Approach. Journal of Hydraulic Engineering, 142(2), 04015044. doi:10.1061/(asce)hy.1943-7900.0001067Noto, L., & Tucciarelli, T. (2001). DORA Algorithm for Network Flow Models with Improved Stability and Convergence Properties. Journal of Hydraulic Engineering, 127(5), 380-391. doi:10.1061/(asce)0733-9429(2001)127:5(380)Zhou, L., Liu, D., & Ou, C. (2011). Simulation of Flow Transients in a Water Filling Pipe Containing Entrapped Air Pocket with VOF Model. Engineering Applications of Computational Fluid Mechanics, 5(1), 127-140. doi:10.1080/19942060.2011.11015357SaemI, S., Raisee, M., Cervantes, M. J., & Nourbakhsh, A. (2018). Computation of two- and three-dimensional water hammer flows. Journal of Hydraulic Research, 57(3), 386-404. doi:10.1080/00221686.2018.1459892Apollonio, C., Balacco, G., Fontana, N., Giugni, M., Marini, G., & Piccinni, A. (2016). Hydraulic Transients Caused by Air Expulsion During Rapid Filling of Undulating Pipelines. Water, 8(1), 25. doi:10.3390/w8010025Wang, L., Wang, F., Karney, B., & Malekpour, A. (2017). Numerical investigation of rapid filling in bypass pipelines. Journal of Hydraulic Research, 55(5), 647-656. doi:10.1080/00221686.2017.1300193Coronado-Hernández, O. E., Fuertes-Miquel, V. S., Besharat, M., & Ramos, H. M. (2018). Subatmospheric pressure in a water draining pipeline with an air pocket. Urban Water Journal, 15(4), 346-352. doi:10.1080/1573062x.2018.1475578Ramezani, L., Karney, B., & Malekpour, A. (2016). Encouraging Effective Air Management in Water Pipelines: A Critical Review. Journal of Water Resources Planning and Management, 142(12), 04016055. doi:10.1061/(asce)wr.1943-5452.0000695Martins, S. C., Ramos, H. M., & Almeida, A. B. (2015). Conceptual analogy for modelling entrapped air action in hydraulic systems. Journal of Hydraulic Research, 53(5), 678-686. doi:10.1080/00221686.2015.1077353Zhou, F., Hicks, F. E., & Steffler, P. M. (2002). Transient Flow in a Rapidly Filling Horizontal Pipe Containing Trapped Air. Journal of Hydraulic Engineering, 128(6), 625-634. doi:10.1061/(asce)0733-9429(2002)128:6(625)Cabrera, E., Abreu, J., Pérez, R., & Vela, A. (1992). Influence of Liquid Length Variation in Hydraulic Transients. Journal of Hydraulic Engineering, 118(12), 1639-1650. doi:10.1061/(asce)0733-9429(1992)118:12(1639

Antimicrobial activity of the essential oils of Dittrichia viscosa subsp viscosa on Helicobacter pylori

Dittrichia viscosa subsp. viscosa (Compositae) is found on edges, wood clearings and in waste places of the Iberian Peninsula. Aerial parts of D. viscosa were collected at flowering phase in September-October 2001 around Lisbon, Portugal and the essential oils isolated by hydro-distillation for 4 h using a Clevenger-type apparatus. The oils were analyzed by gas chromatography and gas chromatography-mass spectrometry. Preliminary examination of the essential oils allowed the identification of 32 components. Only four components reached percentages over 5%: fokienol (11.8%), T-muurorol (7.9%), (E)-nerolidol (5.5%) and delta-cadinene (5.0%). The essential oils were tested against Helicobacterpylori and Listeria monocytogenes. Essential oils did not have antimicrobial activity against L. monocytogenes. The essential oil at 0.88 to 22.22 mu g.ml(-1) did not inhibit the growth of H. pylori, affected the growth slightly at 44.40 mu g.ml(-1), and completely inhibited the growth at 88.80 to 133.20 mu g.ml(-1) Results show that use of D. viscosa essential oil in the treatment of gastric disorders caused by H. pylori can be effective

Mercúrio e metilmercúrio em cores de sedimento do estuário do Tejo

Mestrado em Ciências do Mar e das Zonas CosteirasO mercúrio é actualmente considerado um dos metais mais nocivos para o ambiente. O presente trabalho incide sobre os factores que actuam sobre o mercúrio, influenciando a sua distribuição em ambientes estuarinos. Dado o histórico de contaminação no Estuário do Tejo, foram recolhidos cores de sedimentos e separadas as águas intersticiais em dois locais distintos: um fortemente contaminado, Cala do Norte, e outro não contaminado, Ponta da Erva. Os cores foram seccionados em camadas, tendo-se posteriormente analisado os teores de mercúrio total (HgT) e metilmercúrio (MeHg) na fracção sólida dos sedimentos e HgT e HgR, bem como MeHg dissolvidos nas águas intersticiais. As concentrações de HgT e MeHg foram relacionadas com outros parâmetros obtidos na fracção sólida e nas águas intersticiais, nomeadamente pH, Eh, O2 dissolvido, humidade, e as concentrações de LOI, Al, Si, Fe, Mn, Corg, DOC, Cl-, SO4 2- e HS-. Na Cala do Norte, a concentração de mercúrio total nos sedimentos variou entre 1 e 18 μg/g enquanto na Ponta da Erva foram determinados valores mais baixos, entre 0.4 e 0.5 μg/g. Em relação às concentrações de metilmercúrio, os valores variaram entre os não detectáveis (< 0.1 ng/g) e 87 ng/g na Cala do Norte e 0.54 ng/g na Ponta da Erva. Nos dois locais, apesar da diferença de concentrações, o HgT e MeHg mostraram-se encontrar-se em equilíbrio entre a fracção sólida e águas intersticiais. Os fluxos difusivos foram calculados na interface sedimento/água de modo a estimar a mobilidade das espécies de Hg e avaliar se existem trocas entre o sedimento e a coluna de água, considerando a toxicidade do MeHg. O fluxo estimado na Cala do Norte foi de 0.30 ng/m2d para o MeHg e 0.50 ng/m2d para HgR. Na Ponta da Erva, o fluxo de MeHg foi inferior ao calculado para a Cala do Norte, 0.19 ng/m2d, enquanto para o HgR foi maior, 1.13 ng/m2d. Estes fluxos evidenciam o transporte difusivo de Hg das águas intersticiais para a coluna de água em ambos os locais, reflectindo a importância das características do sedimento que potenciam os processos de metilação do Hg.Mercury is currently considered one of the most harmful metals to the environment. This study focuses on factors that influence mercury distribution and its bioavailability in estuarine environments. Given the history of contamination in the Tagus estuary, sediment cores were collected and pore waters were separated from two sites: one heavily contaminated, Cala do Norte, and a non-contaminated, Ponta da Erva. In the laboratory, the levels of total mercury (Hg) and methylmercury (MeHg) in solid sediments and dissolved Hg (HgR and HgT) and MeHg in the pore waters were analyzed. Obtained Hg data were then compared to other parameters, namely the pH, Eh, dissolved O2, water content, as well the concentrations of LOI, Al, Si, Fe, Mn, Corg, DOC, Cl-, SO4 2- and HS-. In Cala do Norte, total mercury concentrations in sediments ranged between 1 and 18 μg/g while in Ponta da Erva, lower values were determined, ranging between 0.4 and 0.5 μg/g. Concentrations of methylmercury ranged between detection limit (< 0.1 ng/g) up to 87 ng/g in Cala do Norte and up to 0.54 ng/g in Ponta da Erva. In both places, despite the differences in concentrations, HgT and MeHg were in equilibrium between the pore waters and the solid fractions. The diffusive fluxes were calculated across the sediment/water interface in order to estimate the mobility of Hg species and assess whether there are exchanges between the sediment and water column, considering the MeHg toxicity. The estimated flux in Cala do Norte was 0.30 ng/m2d for MeHg and 0.50 ng/m2d for HgR. Conversely, in Ponta da Erva MeHg flux was lower than in Cala do Norte, 0.19 ng/m2d, while for HgR was higher, 1.13 ng/m2d. These fluxes evidence the diffusive transport of Hg from the pore waters to the overlying water in both sites reflecting the importance of sediment characteristics that enhance the Hg methylation processes