Chemosynthetic gas exchanger Final report, 8 Jun. 1964 - 14 Mar. 1967

Chemosynthetic bioregenerative system for long-term space exploration that employs functional coupling of water with biosynthesis by hydrogen bacteri

Modelling the inorganic nitrogen behaviour in a small Mediterranean forested catchment, Fuirosos (Catalonia)

The aim of this work was to couple a nitrogen (N) sub-model to already existent hydrological lumped (LU4-N) and semi-distributed (LU4-R-N and SD4-R-N) conceptual models, to improve our understanding of the factors and processes controlling nitrogen cycling and losses in Mediterranean catchments. The N model adopted provides a simplified conceptualization of the soil nitrogen cycle considering mineralization, nitrification, immobilization, denitrification, plant uptake, and ammonium adsorption/desorption. It also includes nitrification and denitrification in the shallow perched aquifer. We included a soil moisture threshold for all the considered soil biological processes. The results suggested that all the nitrogen processes were highly influenced by the rain episodes and that soil microbial processes occurred in pulses stimulated by soil moisture increasing after rain. Our simulation highlighted the riparian zone as a possible source of nitrate, especially after the summer drought period, but it can also act as an important sink of nitrate due to denitrification, in particular during the wettest period of the year. The riparian zone was a key element to simulate the catchment nitrate behaviour. The lumped LU4-N model (which does not include the riparian zone) could not be validated, while both the semi-distributed LU4-R-N and SD4-R-N model (which include the riparian zone) gave satisfactory results for the calibration process and acceptable results for the temporal validation process

Comparison of Trimethoprim-Sulfamethoxazole with Ampicillin in Acute Infectious Exacerbations of Chronic Bronchitis: A Double-Blind Crossover Study

Two separate acute bacterial exacerbations of chronic bronchitis or chronic asthmatic bronchitis were treated in 20 patients in a double-blind crossover study. One course of treatment consisted of 320 mg of trimethoprim (TMP) plus 1,600 mg of sulfamethoxazole (SMZ) daily and the other of 2 g of ampicillin daily; each drug was given for 14 days. Patients were observed initially, twice a week during therapy, and weekly after therapy. Observations that were recorded included graded chest symptoms and physical findings, vital signs, pulmonary function, hematologic parameters, and objective sputum measurements (daily volume, purulence, differential quantitative cytology, quantitative bacterial counts, physical properties, levels of lactate dehydrogenase with its isoenzymes, levels of myeloperoxidase, and presence of deoxyribonucleic acid fibers). Both antibiotic regimens were effective in resolving these acute bacterial exacerbations. Paired z-test analysis revealed few and minor differences between TMP-SMZ and ampicillin during therapy, although three patients did not complete TMP-SMZ therapy because of adverse reactions. However, the period between the two bacterial exacerbations was significantly longer after ampicillin therapy. Innovative in this investigation are the study design and the objective quantitative measurements of inflammatory response and bacterial populations in sputu

Covalency, double-counting and the metal-insulator phase diagram in transition metal oxides

Dynamical mean field theory calculations are used to show that for late transition-metal-oxides a critical variable for the Mott/charge-transfer transition is the number of d-electrons, which is determined by charge transfer from oxygen ions. Insulating behavior is found only for a narrow range of d-occupancy, irrespective of the size of the intra-d Coulomb repulsion. The result is useful in interpreting 'density functional +U' and 'density functional plus dynamical mean field' methods in which additional correlations are applied to a specific set of orbitals and an important role is played by the 'double counting correction' which dictates the occupancy of these correlated orbitals. General considerations are presented and are illustrated by calculations for two representative transition metal oxide systems: layered perovskite Cu-based "high-Tc" materials, an orbitally non-degenerate electronically quasi-two dimensional systems, and pseudocubic rare earch nickelates, an orbitally degenerate electronically three dimensional system. Density functional calculations yield d-occupancies very far from the Mott metal-insulator phase boundary in the nickelate materials, but closer to it in the cuprates, indicating the sensitivity of theoretical models of the cuprates to the choice of double counting correction and corroborating the critical role of lattice distortions in attaining the experimentally observed insulating phase in the nickelates.Comment: 10+ pages, 5 figure

To be or not to be a conodont. The controversial story of Pseudooneotodus and Eurytholia

The genus Pseudooneotodus (Drygant, 1974) is a genus of small and conical elements widely distributed from the Middle Ordovician to the Early Devonian throughout the world. Because of its unusual shape, Pseudooneotodus has long been considered enigmatic, and only in the late nineties of the last century the genus has been finally placed within conodonts according to histological data. This study investigates possible similarities between Pseudooneotodus and Eurytholia (Sutton et al., 2001), an incertae sedis genus of enigmatic plates with a phosphate composition. An association of over one hundred specimens of Pseudooneotodus beckmanni and Eurytholia bohemica was analyzed from conodont residues in two distinct geographical areas: the Prague Basin (Požáry and Mušlovka sections, Bohemia, Czech Republic) and the Carnic Alps (Rauchkofel Boden section, Austria). Through an investigation that combines the use of optical and electron microscopy (including focused ion beam scanning electron microscopy), X-ray microdiffraction, and trace element (HFSE) analysis by mass spectrometry, differences between these fossil groups were observed and compared with data resulting from typical conodonts (Dapsilodus obliquicostatus, Panderodus unicostatus and Wurmiella excavata) recovered from the same samples

Shallow landslides and rockfalls velocity assessment at regional scale: a methodology based on a morphometric approach

Velocity is one of the most important parameters to evaluate the damaging potential of a mass movement, but its assessment, especially for extremely rapid landslides, is a complex task. In the literature, several models to assess mass movement velocity exist, but they usually require many detailed parameters, and therefore, they are applicable only to a single slope and not usable for regional-scale analyses. This study aims to propose a simple morphometric methodology, based on the spatialisation of the Energy Line method, to determine the velocity of shallow landslides and rockfalls at a regional scale. The proposed method requires a limited amount of input data (landslide perimeters and a digital elevation model), and its application can be carried out using GIS software and a Matlab code. The test area of this work is the Valle d’Aosta Region (Northern Italy), selected due to its peculiar geological and geomorphological setting that makes this region susceptible to the occurrence of both shallow landslides and rockfalls. Since measured velocity values for rockfalls and shallow landslides were not available, the results obtained with the proposed method have been validated through the implementation of a model in the literature, namely the Gravitational Process Path (GPP) model, for some selected landslides

Anesthesia for endobronchial laser surgery: a modified technique

We describe a technique for endobronchial surgery with the neodynium:yttium-aluminum-garnet laser, in which an insufflation catheter with side holes placed into the contralateral mainstem bronchus is used for high-frequency positive pressure ventilation. Thirty-five patients (45 procedures) were treated during general anesthesia using a rigid bronchoscope in combination with a fiberoptic bronchoscope. Perioperatively, oxygen saturation (SaO2), mean arterial pressure, and heart rate were recorded. SaO2 during the recovery period was comparable to that during the intraoperative period but was significantly (P < 0.05) higher than that before the induction of anesthesia. There was a considerable (> or = 5%) increase in SaO2 at the end of the treatment in six patients, which indicates that the recanalization of the treated airway was successful. Our data support the assumption that, during endobronchial resection, selective ventilation of the nonaffected lung was adequate; in addition, subcarinal placement of the insufflation catheter with side holes was advantageous. We conclude that this technique contributes to the prevention of lung complications during endobronchial laser surgery. Implications: We describe a technique in which an insufflation catheter with side holes placed into the contralateral mainstem bronchus largely prevented inhalation of laser smoke and aspiration of blood and debris

Sustainable requalification of architectural and natural resources: the coastal village of Marzamemi

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Phase diagram and single-particle spectrum of CuO2_2 layers within a variational cluster approach to the 3-band Hubbard model

We carry out a detailed numerical study of the three-band Hubbard model in the underdoped region both in the hole- as well as in the electron-doped case by means of the variational cluster approach. Both the phase diagram and the low-energy single-particle spectrum are very similar to recent results for the single-band Hubbard model with next-nearest-neighbor hoppings. In particular, we obtain a mixed antiferromagnetic+superconducting phase at low doping with a first-order transition to a pure superconducting phase accompanied by phase separation. In the single-particle spectrum a clear Zhang-Rice singlet band with an incoherent and a coherent part can be seen, in which holes enter upon doping around $(\pi/2,\pi/2)$. The latter is very similar to the coherent quasi-particle band crossing the Fermi surface in the single-band model. Doped electrons go instead into the upper Hubbard band, first filling the regions of the Brillouin zone around $(\pi,0)$. This fact can be related to the enhanced robustness of the antiferromagnetic phase as a function of electron doping compared to hole doping.Comment: 14 pages, 15 eps figure

ALKALINE HYDROTHERMAL STABILIZATION OF Cr(VI) IN A SANDY SOIL

Chromium (Cr) pollution of soil is a serious environmental problem, especially in industrialized areas. Risks for human and environmental health are strictly connected to Cr oxidation state, which is usually trivalent or hexavalent in soil. While Cr(III) is stable, scarcely mobile and weakly toxic, Cr(VI) is highly soluble, mobile and carcinogenic. Among the different remediation strategies, stabilization/solidification (S/S) is used as rapid and cost-effective technique for heavy metal polluted soils. It consists of the addition of appropriate materials to the polluted soil, mostly under alkaline conditions, in order to chemically and/or physically transform the contaminant in a stable and less toxic form. Waste materials like coal fly ash or other cheap sources of Si and Al can be used to stabilize heavy metals in soil (Terzano et al., 2005). This study aims at evaluating a new S/S process for the reduction of Cr(VI) to Cr(III) in polluted soils and the incorporation of Cr(III) in newly formed minerals by using a reactive mixture of glass and aluminum (recovered from solid municipal wastes) and an alkaline hydrothermal treatment