Structural and enzymatic characterization of ABgp46, a novel phage endolysin with broad anti-Gram-negative bacterial activity

The present study demonstrates the antibacterial potential of a phage endolysin against Gram-negative pathogens, particularly against multidrug resistant strains of Acinetobacter baumannii. We have cloned, heterologously expressed and characterized a novel endolysin (ABgp46) from Acinetobacter phage vb_AbaP_CEB1 and tested its antibacterial activity against several multidrug-resistant A. baumannii strains. LC-MS revealed that ABgp46 is an N-acetylmuramidase, that is also active over a broad pH range (4.0-10.0) and temperatures up to 50°C. Interestingly, ABgp46 has intrinsic and specific anti-A. baumannii activity, reducing multidrug resistant strains by up to 2 logs within 2 hours. By combining ABgp46 with several organic acids that act as outer membrane permeabilizing agents, it is possible to increase and broaden antibacterial activity to include other Gram-negative bacterial pathogens. In the presence of citric and malic acid, ABgp46 reduces A. baumannii below the detection limit (> 5 log) and more than 4 logs P. aeruginosa and Salmonella Typhimurium strains. Overall, this globular endolysin exhibits a broad and high activity against Gram-negative pathogens, that can be enhanced in presence of citric and malic acid, and be used in human and veterinary medicine.

Gestão integrada dos recursos hídricos da região de Fafe: caracterização da qualidade das águas superficiais, potencial hidrogeológico das rochas fraturadas

Dissertação de mestrado em Geociências (área de especialização em Recursos Geológicos)

Интерпретация геолого-геофизических данных методом сейсмостратиграфии

წარმოდგენილ სტატიაში ყურადღება გამახვილებულია გეოფიზიკური კვლევის შედარებით ახალ მეთოდზე – სეისმოსტრატიგრაფიაზე, რომელიც საკმაო დამაჯერებლობით გვიჩვენებს დანალექი ფორმაციების სივრცორბრივ ორიენტაციას. საუბარია სეისმოსტრატიგრაფიული მეთოდის გამოყენების ფართო შესაძლებლობებზე.

Глубинное геолого-геофизическое строение профиля лиси-душети по данным комплексных геофизических исследовании

გარდატეხილი ტალღების კორელაციური და არეკვლილი ტალღების საერთო სიღრმული წერტილის მეთოდების მიხედვით აგებულია ლისი-დუშეთის პროფილის სეისმოგეოლოგიური ჭრილი. მასში გამოყოფილი ჰორიზონტების ასაკობრივი დონეები და ლითოფაციალური აგებულება, ძირითადად, განსაზღვრულია ლისისა და ბიწმინდის ჭაბურღილების მონაცემებით. ამასთან, ჭრილი სეისმოტომოგრაფიულად მიბმულია შინდისისა და ქიწნისის ჭაბურღილებთან. აგებულია ლისი-დუშეთის პროფილის სეისმოტომოგრაფილი ჭრილი, სადაც ნათლად გამოიყოფა დანალექი ფორმაციების სიმძლავრეები და გავრცელების კონტურები, რაც კარგ თანხვედრაშია სეისმოგეოლოგიურ ჭრილთან.

Исследование геофизическими методами инженерно-геологических условий в районе строительства гидроэлектростанции (ГЭС) на реке Мтквари

მდინარე მტკვარზე ჰიდროელექტროსადგურის მშენებლობის რაიონის საინჟინრო-გეოლოგიური პირობების გამოკვლევა გეოფიზიკური მეთოდებით გეოფიზიკური გამოკვლევების შედეგად შესწავლილია მდ. მტკვარზე ჰიდროელექტროსადგურის მშენებლობის რაიონის საინჟინრო-გეოლოგიური პირობები. დადგენილია იქ გავრცელებული ნალექების სიმძლავრეები და ფიზიკური პარამეტრები. გამოვლენილია მეწყრული და პოტენციურად მეწყერსაშიში უბნები და დადგენილია მათში ფილტრაციის გაბატონებული მიმართულება. შეფასებულია ჰეს მშენებლობის რაიონის სეისმურობა.

Определение мощности и фракционной дифференциации селевых наносов в пойме р. Дуруджи по геофизическим данным

სტატიაში მოცემულია დურუჯის აუზში სელური ნალექების სიმძლავრის, ფრაქციული დიფერენციაციის, გაწყლიანების ხარისხის, ძირითადი ქანების ლითოლოგიური არაერთგვაროვნების, მიკროტექტონიკური სურათის დაზუსტება და მიწისქვეშა ფილტრაციული ნაკადის გაბატონებული მიმართულების დადგენა ძიების გეოფიზიკური (გეოელექტრული და სეისმომეტრიული) მეთოდებით.

Исследование инженерно и гидро-геологических условий Маднеульского рудного поля геофизическими методами разведки

საინჟინრო-გეოფიზიკური გამოკვლევების საფუძველზე შესაძლებელი გახდა ფოლადაურის აუზში მეოთხეული ნალექების დანაწევრება ნივთიერი შედგენილობისა და გაწყლიანების ხარისხის მიხედვით.

Результаты исследований по международным геофизическим проектам

В книге представлены результаты многолетних исследований вариаций приземного, общего содержания и вертикального распределения озона в Грузии в сязи с атмосферными процессами

Seasonal abundance of the shipworm Neoteredo reynei (Bivalvia, Teredinidae) in mangrove driftwood from a northern Brazilian beach

Shipworms are important decomposers of wood, especially in mangrove forests where productivity is high. However, little emphasis has been given to the activity of shipworms in relation to the export of nutrients from mangroves to adjacent coastal areas. As a first step to obtaining such information, the frequency of colonized mangrove driftwood as well as shipworm density and length were studied by collecting washed up logs during a year at Ajuruteua beach, state of Pará, northern Brazil. A single species, Neoteredo reynei (Bartsch, 1920), was found colonizing driftwood. Although large colonized logs were most common on the beach, shipworm density was higher in small logs, especially during the dry season. In general, however, density was higher during the wet season (January to April) and lowest in July. Overall shipworm mean length was 9.66cm. In large logs, mean length increased between the wet and dry seasons. However, there was no difference in length among log size categories. Mean shipworm length was similar throughout most of the year but tended to be greater in July. Although salinity varied between 10.9 and 40 during the year, no relationship was found between salinity and density or length. The results suggest that shipworm activity in driftwood logs is relatively constant throughout the year. Increased air humidity and rainfall may promote survival during the wet season. Large logs may take longer to colonize and thus have lower densities than small ones which are scarce probably because they are destroyed rapidly by shipworm activity. However, data on the disintegration of logs would be necessary to test this hypothesis. Larger size of shipworms in the dry season may be related to growth after an earlier recruitment period. Shipworms in large logs during the dry season may be better protected from dessication and high temperatures by the insulating properties of the larger volume of wood.

Cosa: arqueologia de un enclave comercial mediterráneo. Campaña de 2006

En el marco del proyecto “La ciutat romana de Cosa: arqueologia d’un enclau comercial mediterrani” , autorizado y apoyado por la Soprintendenza Archeologica por la Toscana, entre los dias 4 y 22 de septiembre de 2006 se ha realizado la segunda campaña de intervenciones arqueológicas en la ciudad romana de Cosa (Ansedonia, prov. Grosseto, Itàlia), colonia latina fundada en el 273 aC a unos 120 km. al norte de Roma. De acuerdo a los resultados obtenidos en la campanya del 2005 (localización/verificación de los límites precisos de la ínsula O-P/4-5 mediante la aplicación de técnicas de prospección geofísica completadas con la limpieza, registro y documentación arqueológica de las estructuras localizadas ) los trabajos del 2006 se han orientado hacia la identificación de la organización interna de la dicha ínsula tomando como referente el criptopórtico situado en el extremo N.E., el cual parece constituir el límite de una estructura singular (privada o pública ) estratégicamente ubicada en relación al fórum i a la Via Sacra. El trabajo de campo ha consistido en un intenso decapage con la finalidad de delimitar unidades de habitación complejas funcionalmente definidas y así la articulación existente entre ellas; en este sentido se ha podido documentar evidencias del espacio porticado superpuesto al criptopórtico así como, paralelamente a la calle 5 y en dirección a la Via Sacra, parte de habitaciones algunas de las cuales conservaban restos del pavimiento original, en un caso de mosaico. Paralelamente, se ha realizado el análisis en laboratorio de los materiales recuperados los cuales, aún procediendo de nivel superficial, empiezan a proporcionar datos sobre los diferentes momentos de ocupación de la zona, básicamente tardorepublicanos y augustales.

Hydrogeophysical data integration at larger scales: Application of Bayesian sequential simulation for the characterization of heterogeneous alluvial aquifers

Knowledge of the spatial distribution of hydraulic conductivity (K) within an aquifer is critical for reliable predictions of solute transport and the development of effective groundwater management and/or remediation strategies. While core analyses and hydraulic logging can provide highly detailed information, such information is inherently localized around boreholes that tend to be sparsely distributed throughout the aquifer volume. Conversely, larger-scale hydraulic experiments like pumping and tracer tests provide relatively low-resolution estimates of K in the investigated subsurface region. As a result, traditional hydrogeological measurement techniques contain a gap in terms of spatial resolution and coverage, and they are often alone inadequate for characterizing heterogeneous aquifers. Geophysical methods have the potential to bridge this gap. The recent increased interest in the application of geophysical methods to hydrogeological problems is clearly evidenced by the formation and rapid growth of the domain of hydrogeophysics over the past decade (e.g., Rubin and Hubbard, 2005).

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Developing a predictive understanding of subsurface flow and transport is complicated by the disparity of scales across which controlling hydrological properties and processes span. Conventional techniques for characterizing hydrogeological properties (such as pumping, slug, and flowmeter tests) typically rely on borehole access to the subsurface. Because their spatial extent is commonly limited to the vicinity near the wellbores, these methods often cannot provide sufficient information to describe key controls on subsurface flow and transport. The field of hydrogeophysics has evolved in recent years to explore the potential that geophysical methods hold for improving the quantification of subsurface properties and processes relevant for hydrological investigations. This chapter is intended to familiarize hydrogeologists and water-resource professionals with the state of the art as well as existing challenges associated with hydrogeophysics. We provide a review of the key components of hydrogeophysical studies, which include: geophysical methods commonly used for shallow subsurface characterization; petrophysical relationships used to link the geophysical properties to hydrological properties and state variables; and estimation or inversion methods used to integrate hydrological and geophysical measurements in a consistent manner. We demonstrate the use of these different geophysical methods, petrophysical relationships, and estimation approaches through several field-scale case studies. Among other applications, the case studies illustrate the use of hydrogeophysical approaches to quantify subsurface architecture that influence flow (such as hydrostratigraphy and preferential pathways); delineate anomalous subsurface fluid bodies (such as contaminant plumes); monitor hydrological processes (such as infiltration, freshwater-seawater interface dynamics, and flow through fractures); and estimate hydrological properties (such as hydraulic conductivity) and state variables (such as water content). The case studies have been chosen to illustrate how hydrogeophysical approaches can yield insights about complex subsurface hydrological processes, provide input that improves flow and transport predictions, and provide quantitative information over field-relevant spatial scales. The chapter concludes by describing existing hydrogeophysical challenges and associated research needs. In particular, we identify the area of quantitative watershed hydrogeophysics as a frontier area, where significant effort is required to advance the estimation of hydrological properties and processes (and their uncertainties) over spatial scales relevant to the management of water resources and contaminants.

Potent synergism of the combination of fluconazole and cyclosporine in Candida albicans.

Several types of drugs currently used in clinical practice were screened in vitro for their potentiation of the antifungal effect of the fungistatic agent fluconazole (FLC) on Candida albicans. These drugs included inhibitors of multidrug efflux transporters, antimicrobial agents, antifungal agents, and membrane-active compounds with no antimicrobial activity, such as antiarrhythmic agents, proton pump inhibitors, and platelet aggregation inhibitors. Among the drugs tested in an agar disk diffusion assay, cyclosporine (Cy), which had no intrinsic antifungal activity, showed a potent antifungal effect in combination with FLC. In a checkerboard microtiter plate format, however, it was observed that the MIC of FLC, as classically defined by the NCCLS recommendations, was unchanged when FLC and Cy were combined. Nevertheless, if a different reading endpoint corresponding to the minimal fungicidal concentration needed to decrease viable counts by at least 3 logs in comparison to the growth control was chosen, the combination was synergistic (fractional inhibitory concentration index of <1). This endpoint fitted to the definition of MIC-0 (optically clear wells) and reflected the absence of the trailing effect, which is the result of a residual growth at FLC concentrations greater than the MIC. The MIC-0 values of FLC and Cy tested alone in C. albicans were >32 and >10 microg/ml, respectively, and decreased to 0.5 and 0.625 microg/ml when the two drugs were combined. The combination of 0.625 microg of Cy per ml with supra-MICs of FLC resulted in a potent antifungal effect in time-kill curve experiments. This effect was fungicidal or fungistatic, depending on the C. albicans strain used. Since the Cy concentration effective in vitro is achievable in vivo, the combination of this agent with FLC represents an attractive perspective for the development of new management strategies for candidiasis.

Comment on "Streaming potential dependence on water-content in Fontainebleau sand" by V. Allegre, L. Jouniaux, F. Lehmann and P. Sailhac

Allegre et al. recently presented new experimental data regarding the dependence of the streaming potential coupling coefficient with the saturation of the water phase. Such experiments are important to model the self-potential response associated with the flow of water in the vadose zone and the electroseismic/seismoelectric conversions in unsaturated porous media. However, the approach used to interpret the data is questionable and the conclusions reached by Allegre et al. likely incorrect