Characterization of Attachment and Growth of Thiobacillus denitrificans on Pyrite Surfaces

Anaerobic growth and attachment of the autotrophic denitrifying bacterium Thiobacillus denitrificans on pyrite surfaces were studied. Polished pyrite slabs were exposed to T. denitrificans for 1 to 9 weeks. The reacted pyrite surfaces were imaged with scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). Cells were observed as isolated attached cells, cells in division and cells forming microcolonies embedded in organic films. Bacteria began to colonize pyrite surfaces after 1 week, forming microcolonies after 3 weeks. The rate of colonization of the pyrite surface was around 35 cells mm−2 h−1 for the 3-week period. After 9 weeks, larger areas of the pyrite surface were covered by organic films. Bacterial enumeration on the pyrite surface and in solution showed that most of the cells were not attached to the mineral surface. Nevertheless, both attached and free-living bacteria probably contributed to pyrite-driven denitrification. The results may be applied to the natural environment to better understand pyrite-driven denitrification in aquifers and to improve the long-term performance of bioremediation processes using pyrite

Novedades en torno a la posible localización de Iturissa (Espinal/Burguete, Navarra)

En esta breve contribución queremos dar a conocer los recientes descubrimientos llevados a cabo en término de Espinal y Burguete (Navarra) rela- cionados con los importantes yacimientos de época romana excavados en el lugar entre 1986 y 1994. A la espera de los resultados del estudio de los miliarios de Asibar y de los materiales recuperados en los sondeos de Zaldúa gracias a esos descubrimientos, y al trabajo de años precedentes, queda patente la exis- tencia de un importante asentamiento, posiblemente identificado con Iturissa.In this short report we want to show the recent discoveries made in Espinal and Burguete (Navarra), related with the significant findings of roman times excavated between 1986 and 1994. While waiting for the final results of the milestones of Asibar study and those about the materials recovered in Zaldúa, it is clear –by those findings but also by the ancient ones– the existence of an important settlement, identified possibly as Iturissa

IAMSEST secundario a síndrome de Kounis tipo I inducido por alimentos

Kounis syndrome is characterized by an acute coronary episode in the context of an anaphylactic reaction; the pathophysiology is varied but is based on the release of vasoactive substances from mast cell degranulation. We present a case of a patient who debuted as a NSTEMI in the context of anaphylactic shock triggered by food. The patient presented angina, abnormalities in electrocardiogram, and troponin elevation; echocardiography and coronary angiography were normal. The patient responded favorably to treatment with corticosteroids, antihistamines and antiplatelet agents. He was discharged without symptoms.El síndrome de Kounis se caracteriza por un episodio coronario agudo en el contexto de una reacción anafiláctica; la fisiopatología es variada, pero se basa en la liberación de sustancias vasoactivas derivadas de la degranulación de los mastocitos. Se presenta el caso de un paciente que debutó como un IAMSEST en el contexto de un shock anafiláctico desencadenado por alimentos; presentó angina, alteraciones en el electrocardiograma y elevación de troponinas, la ecocardiografía y la coronariografía fueron normales. El paciente presentó evolución favorable con tratamiento a base de corticoides, antihistamínicos y antiagregantes, y fue dado de alta asintomático

Origin, accumulation and fate of dissolved organic matter in an extreme hypersaline shallow lake

Hypersaline endorheic aquatic systems (H-SEAS) are lakes/shallow playas in arid and semiarid regions that undergo extreme oscillations in salinity and severe drought episodes. Although their geochemical uniqueness and microbiome have been deeply studied, very little is known about the availability and quality of dissolved organic matter (DOM) in the water column. A H-SEAS from the Monegros Desert (Zaragoza, NE Spain) was studied during a hydrological wetting-drying-rewetting cycle. DOM analysis included: (i) a dissolved organic carbon (DOC) mass balance; (ii) spectroscopy (absorbance and fluorescence) and (iii) a molecular characterization with Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). The studied system stored a large amount of DOC and under the highest salinity conditions, salt-saturated waters (i.e., brines with salinity > 30%) accumulated a disproportionate quantity of DOC, indicating a significant in-situ net DOM production. Simultaneously, during the hydrological transition from wet to dry, the DOM pool showed strong alterations of it molecular composition. Spectroscopic methods indicated that aromatic and degraded DOM was rapidly replaced by fresher, relatively small, microbial-derived moieties with a large C/N ratio. FT-ICR-MS highlighted the accumulation of small, saturated and oxidized molecules (molecular O/C > 0.5), with a remarkable increase in the relative contribution of highly oxygenated (molecular O/C > 0.9) compounds and a decrease of aliphatic and carboxyl-rich alicyclic moleculesThese results indicated that H-SEAS are extremely active in accumulating and processing DOM, with the notable release of organic solutes probably originated from decaying microplankton under large osmotic stress at extremely high salinitie

El hepatocarcinoma en la Comunidad Foral de Navarra: estudio de características y evolución en la práctica clínica habitual

Fundamento. El hepatocarcinoma asienta generalmente sobre una cirrosis hepática. El cribado pretende mejorar la supervivencia. Los objetivos de nuestro trabajo son conocer las características del hepatocarcinoma, su evolución y la influencia del cribado en su supervivencia, en la práctica clínica en Navarra. Material y Métodos. Estudio prospectivo y retrospectivo de 111 pacientes diagnosticados de hepatocarcinoma en hospitales públicos navarros, entre enero de 2009 y enero de 2015. Se analizaron características epidemiológicas, clínicas, analíticas, radiológicas, estadio tumoral, tratamiento y evolución, y el efecto del cribado. Resultados. El 84,7% de los pacientes eran varones. La edad media fue 67 años. El 85,6% tenían cirrosis. La etiología más frecuente fue la enólica (40,7%). El 62,2% se diagnosticó en estadios tempranos, el 15,3% en intermedio y el 22,5% en avanzado o terminal. El 4,5% se trató mediante trasplante, el 21,6% con resección, el 23,4% mediante ablación, el 10,8% con quimioembolización, el 5,4% con radiembolización, el 2,7% con embolización, el 13,5% con sorafenib y el 18% de modo sintomático. Solamente 32 pacientes (28,8%) realizaban cribado. No se han encontrado diferencias significativas en la supervivencia según la realización de cribado (mediana de 32 y 34 meses; p = 0,971). Conclusiones. En Navarra, el hepatocarcinoma se desarrolla generalmente sobre una cirrosis, cuya etiología más frecuente es el consumo de alcohol. El hepatocarcinoma se ha diagnosticado con más frecuencia en estadios iniciales, fuera de cribado. El cribado no ha mejorado la supervivencia.Background. Hepatocellular carcinoma generally arises in a cirrhotic liver. The aim of screening is to improve survival. The aims of our study are to determine the characteristics and evolution of hepatocellular carcinoma and the effect of screening on survival, in clinical practice in Navarre. Methods. Prospective and retrospective study of 111 patients diagnosed with hepatocellular carcinoma in public hospitals in Navarre between January 2009 and January 2015. Epidemiological, clinical, analytical, radiological characteristics, tumour staging, treatment and evolution were analyzed. Survival was compared between patients subjected to screening and those not. Results. Mean age was 67 years. The patients (84.7%) were mainly male and 85.6% had cirrhosis. The most frequent aetiology was alcohol consumption (40.7%). 62.2% were diagnosed in early stages, 15.3% in intermediate and 22.5 % in advanced or terminal stages. 4.5% received transplants, 21.6% received surgical resection, 23.4% were treated with ablation techniques, 10.8 % with chemoembolization, 5.4% with radiembolization, 2.7% with embolization, 13.5 % with sorafenib and 18% symptomatically. Only 32 patients (28.8%) were subjected to screening. No statistical differences were found in survival depending on surveillance (32 month versus 34; p = 0.971). Conclusions. In Navarre, hepatocellular carcinoma generally appears against a background of cirrhosis, and alcohol is the most frequent aetiology. Hepatocellular carcinoma is diagnosed most frequently in early stages and out of screening practices. Screening was not associated to better survival

Professional development programmes for teachers moving from majority to minoritised language medium education:Lessons from a comparative study

Education through the medium of a minoritised language is widely regarded as a critical component of language revitalisation initiatives. Given the demographic and social position of many minoritised languages, however, it may not be easy to find teachers who are fluent and literate in the language, confident about using and teaching it, and prepared for the demands of working in classrooms where the language is the medium of instruction. This article presents findings from a comparative study of teacher education programmes adopted in Catalonia, the Basque Autonomous Community, Wales and New Zealand, to prepare teachers to teach through the media of Catalan, Basque, Welsh and Māori respectively. The research was conducted to inform new professional development initiatives in Scotland, designed to enable qualified teachers to transfer from English-medium to Gaelic-medium education. The findings have wider relevance for other contexts in which the recruitment, professional development and retention of teachers to work in minoritised language medium education represent a challenge

Finite-memory strategies in POMDPs with long-run average objectives

Partially observable Markov decision processes (POMDPs) are standard models for dynamic systems with probabilistic and nondeterministic behaviour in uncertain environments. We prove that in POMDPs with long-run average objective, the decision maker has approximately optimal strategies with finite memory. This implies notably that approximating the long-run value is recursively enumerable, as well as a weak continuity property of the value with respect to the transition function