Water as a weapon in ancient times: considerations of technical and ethical aspects

This paper addresses the issue of how water played a role in ancient conflicts, from the poisoning of water sources to flooding, to stop the advance of enemy armies. It deals with military actions quoted by several ancient Greek and Roman authors, who in some cases narrate these experiences first-hand. Although many abhorred such actions, they were considered tactical expedients to resort to, as cited by the war manuals of the time. The analysis starts from the 'manual' Strategemata of Sextus Julius Frontinus, in addition to other references left by historians and chroniclers of different periods. It continues with the evaluation of the impact of the intentional actions of water contamination described by the ancient authors, according to present toxicological and health knowledge

Physical hydrogels of poly(vinyl alcohol) with different syndiotacticity prepared in the presence of lactosylated chitosan derivative

Poly(vinyl alcohol) (PVA) physical hydrogels were prepared by repeated freeze-thawing cycles using aqueous solutions of two PVA samples having different degrees of syndiotacticity, a-PVA and s-PVA with 55% and 61% of syndiotactic diads, respectively. The hydrogels were prepared in the presence of different amounts of lactosilated chitosan derivatives (LC) of different molecular weight. The PVA stereoregularity was found to have a dramatic effect on the amount of PVA incorporated into the hydrogels, leading to remarkable differences in the swelling degree and porosity of a-PVA and s-PVA hydrogels. A significant amount of LC was retained in the hydrogels after equilibrium swelling. The swelling of the a-PVA hydrogels was found to increase significantly by increasing the amount of LC while it was only slightly increased in the case of s-PVA hydrogels. The amount of LC released after equilibrium swelling was lower when chitosan derivatives with higher molecular weights were used. Increased initial concentrations of LC resulted in much higher porosity of the hydrogels. TGA and DSC studies showed that LC is stabilized by the incorporation in the PVA hydrogels. The mellting temperature of the crystalline regions of PVA was not significantly influ need by LC. Conversely, the extension of the crystalline domains increased in the presence of LC. The retention of a chitosan derivative bearing β-D-galactose side chain residues makes these hydrogels potentially useful as scaffolds for hepatocytes culture

Subcritical Water Extraction Followed by Liquid Chromatography Mass Spectrometry for Determining Terbuthylazine and Its Metabolites in Aged and Incubated Soils

Due to the great potential of atrazine in contaminating groundwater, its use has been banned in several countries and often replaced by terbuthylazine (CBET). Little is known on the fate of CBET in soil. The purpose of this work has been (1) to develop a general method for analysing CBET and its degradation products (DPs) in soil and (2) to use this method for elucidating the fate of CBET incubated in both surface and subsurface samples of an agricultural soil which had been receiving repeated CBET spills. This method involves analyte extraction from soil at 100 degrees C by phosphate-buffered water. Analytes coming out of the extraction cell were collected by a graphitized carbon black extraction cartridge. After analyte elution with a suitable solvent mixture, the final extract was analyzed by LC-MS. From an aged soil, our method extracted altogether quantities of CBET and its DPs respectively 2.1 and 1.4 times larger than those by two previously reported methods. For the analytes considered, limits of quantification (S/N 10) ranged between 0.22 and 5.5 ng per gram of soil. The laboratory CBET degradation experiment showed that (1) similarly to atrazine, remarkable amounts of hydroxylated metabolites were formed; (2) when the subsoil microflora was in the presence of rather large amounts of CBET, it degraded the herbicide with a rate similar to that of the topsoil microflora

Alginate beads as immobilization matrix for hepatocytes perfused in bioreactor. A physico-chemical characterization

Because of their peculiar physico-chem. properties, alginate beads have often been proposed as an alternative cell immobilization matrix for many biotechnol. applications. For entrapped hepatocytes perfused in a bioreactor, alginate beads have been demonstrated to promote viability and three-dimensional cell organization. In order to optimize the hepatocyte cell culture, we investigated the relationship between alginate beads properties, at high and low content of guluronic acid (G), and the relative cell viability and reorganization when perfused in a bioreactor. The primary structure of alginates did not apparently influence the hepatocytes culture in 8 h of perfusion in a bioreactor. However, our results confirm a preference for beads with a high content of G due to their superior mech. resistance

The <it>MP65 gene </it>is required for cell wall integrity, adherence to epithelial cells and biofilm formation in <it>Candida albicans</it>

<p>Abstract</p> <p>Background</p> <p>The <it>MP65 </it>gene of <it>Candida albicans </it>(orf19.1779) encodes a putative β-glucanase mannoprotein of 65 kDa, which plays a main role in a host-fungus relationship, morphogenesis and pathogenicity. In this study, we performed an extensive analysis of a <it>mp65Δ </it>mutant to assess the role of this protein in cell wall integrity, adherence to epithelial cells and biofilm formation.</p> <p>Results</p> <p>The <it>mp65Δ </it>mutant showed a high sensitivity to a range of cell wall-perturbing and degrading agents, especially Congo red, which induced morphological changes such as swelling, clumping and formation of hyphae. The <it>mp65Δ </it>mutant showed an activation of two MAPKs (Mkc1p and Cek1p), a high level of expression of two stress-related genes (DDR48 and <it>SOD5</it>), and a modulated expression of β-glucan epitopes, but no gross changes in cell wall polysaccharide composition. Interestingly, the <it>mp65Δ </it>mutant displayed a marked reduction in adhesion to BEC and Caco-2 cells and severe defects in biofilm formation when compared to the wild type. All of the mentioned properties were totally or partially recovered in a revertant strain, demonstrating the specificity of gene deletion.</p> <p>Conclusions</p> <p>We demonstrate that the <it>MP65 </it>gene of <it>Candida albicans </it>plays a significant role in maintaining cell wall integrity, as well as in adherence to epithelia and biofilm formation, which are major virulence attributes of this fungus.</p

DA&#x003A6;NE &#x003A6;-factory upgrade for Siddharta run

An upgrade of the ΦNE Φ-Factory at LNF is planned in view of the installation of the Siddharta detector in fall 2007. A new interaction region suitable to test the large Piwinski angle and crab waist (CW) collision schemes will be installed. Other machine improvements, such as new injection kickers, bellows and beam pipe layouts will be realized, with the goal of reaching luminosity of the order of 1033/cm2 /s. The principle of operation of the new scheme, together with hardware designs and simulation studies, are presented

DA Phi NE Upgrade Status

The DA Phi NE Phi-factory at lNFN-LNF has been upgraded in the second half of 2007 with the scope of testing a recently proposed scheme of crab waist collisions. New vacuum chambers and permanent quadrupole magnets have been designed, fabricated and installed to realize the new configuration. The ring injection systems have been also modified with the installation of new stripline fast injection kickers. Moreover the old bellows have been substituted by the new ones and all ion clearing electrodes in the electron ring have been removed. In the talk we describe the new layout as well as several experimental results obtained during the new run