Biosorption potential of zinc by egeria densa macrophytes

In this paper, the removal potential on Zn ion by macrophyte Egeria densa has been studied. The influence of the metal solution pH, the plant drying and the metal solution temperature, and biosorbent grain size was previously studied in batch systems. Adsorption kinetic and equilibrium experiments of metals onto E. densa were performed under controlled temperature and permanent shaking. In adsorption kinetic tests for Zn (II) the equilibrium time was around 45 min. The biosorption kinetic data were well fitted by a pseudo-second order model. The equilibrium data at pH 5 were described a rather better by the Langmuir isotherm than the Freundlich one, with an adsorption rate and maximum metal content values of 0,829L g(-1)and 0,92 mequiv g(-1), respectively, for Langmuir model. The macrophytes E. densa could be used as biosorbent material in industrial effluent treatment system.14446547

Bacteriophage Crosstalk: Coordination of Prophage Induction by Trans-Acting Antirepressors

Many species of bacteria harbor multiple prophages in their genomes. Prophages often carry genes that confer a selective advantage to the bacterium, typically during host colonization. Prophages can convert to infectious viruses through a process known as induction, which is relevant to the spread of bacterial virulence genes. The paradigm of prophage induction, as set by the phage Lambda model, sees the process initiated by the RecA-stimulated self-proteolysis of the phage repressor. Here we show that a large family of lambdoid prophages found in Salmonella genomes employs an alternative induction strategy. The repressors of these phages are not cleaved upon induction; rather, they are inactivated by the binding of small antirepressor proteins. Formation of the complex causes the repressor to dissociate from DNA. The antirepressor genes lie outside the immunity region and are under direct control of the LexA repressor, thus plugging prophage induction directly into the SOS response. GfoA and GfhA, the antirepressors of Salmonella prophages Gifsy-1 and Gifsy-3, each target both of these phages' repressors, GfoR and GfhR, even though the latter proteins recognize different operator sites and the two phages are heteroimmune. In contrast, the Gifsy-2 phage repressor, GtgR, is insensitive to GfoA and GfhA, but is inactivated by an antirepressor from the unrelated Fels-1 prophage (FsoA). This response is all the more surprising as FsoA is under the control of the Fels-1 repressor, not LexA, and plays no apparent role in Fels-1 induction, which occurs via a Lambda CI-like repressor cleavage mechanism. The ability of antirepressors to recognize non-cognate repressors allows coordination of induction of multiple prophages in polylysogenic strains. Identification of non-cleavable gfoR/gtgR homologues in a large variety of bacterial genomes (including most Escherichia coli genomes in the DNA database) suggests that antirepression-mediated induction is far more common than previously recognized

DNA Damage and Reactive Nitrogen Species are Barriers to Vibrio cholerae Colonization of the Infant Mouse Intestine

Ingested Vibrio cholerae pass through the stomach and colonize the small intestines of its host. Here, we show that V. cholerae requires at least two types of DNA repair systems to efficiently compete for colonization of the infant mouse intestine. These results show that V. cholerae experiences increased DNA damage in the murine gastrointestinal tract. Agreeing with this, we show that passage through the murine gut increases the mutation frequency of V. cholerae compared to liquid culture passage. Our genetic analysis identifies known and novel defense enzymes required for detoxifying reactive nitrogen species (but not reactive oxygen species) that are also required for V. cholerae to efficiently colonize the infant mouse intestine, pointing to reactive nitrogen species as the potential cause of DNA damage. We demonstrate that potential reactive nitrogen species deleterious for V. cholerae are not generated by host inducible nitric oxide synthase (iNOS) activity and instead may be derived from acidified nitrite in the stomach. Agreeing with this hypothesis, we show that strains deficient in DNA repair or reactive nitrogen species defense that are defective in intestinal colonization have decreased growth or increased mutation frequency in acidified nitrite containing media. Moreover, we demonstrate that neutralizing stomach acid rescues the colonization defect of the DNA repair and reactive nitrogen species defense defective mutants suggesting a common defense pathway for these mutants

Viel Lärm um nichts? : Diversity im beruflichen Kontext

Obwohl Diversity erst in den letzten Jahren in vielen Organisationen zu einer Art „Modethema“ avanciert ist, handelt es sich um ein alltägliches Phänomen, mit dem die meisten Menschen seit jeher an ihrem Arbeitsplatz konfrontiert werden: Sie arbeiten mit anderen Personen zusammen, die sich hinsichtlich zahlreicher Merkmale (Alter, Geschlecht, Persönlichkeit etc.) voneinander unterscheiden. Empirische Studien verdeutlichen, dass sich aus dieser Zusammenarbeit Vorteile und Nachteile ergeben können. Die Effekte sind jedoch so gering, dass sie im Durchschnitt kaum eine Bedeutung haben. Wer die Effizienz einer Organisation steigern möchte, findet in der Personalauswahl, der Personalentwicklung sowie der Führung sehr viel effektivere Ansatzpunkte. Dennoch kann es Konstellationen geben, in denen es durchaus sinnvoll ist, sich aktiv mit der Heterogenität von Arbeitsgruppen auseinanderzusetzen, um unproduktive Konflikte zu vermeiden und das Potential der Heterogenität zu nutzen

Viel Lärm um nichts? : Diversity im beruflichen Kontext

Obwohl Diversity erst in den letzten Jahren in vielen Organisationen zu einer Art „Modethema“ avanciert ist, handelt es sich um ein alltägliches Phänomen, mit dem die meisten Menschen seit jeher an ihrem Arbeitsplatz konfrontiert werden: Sie arbeiten mit anderen Personen zusammen, die sich hinsichtlich zahlreicher Merkmale (Alter, Geschlecht, Persönlichkeit etc.) voneinander unterscheiden. Empirische Studien verdeutlichen, dass sich aus dieser Zusammenarbeit Vorteile und Nachteile ergeben können. Die Effekte sind jedoch so gering, dass sie im Durchschnitt kaum eine Bedeutung haben. Wer die Effizienz einer Organisation steigern möchte, findet in der Personalauswahl, der Personalentwicklung sowie der Führung sehr viel effektivere Ansatzpunkte. Dennoch kann es Konstellationen geben, in denen es durchaus sinnvoll ist, sich aktiv mit der Heterogenität von Arbeitsgruppen auseinanderzusetzen, um unproduktive Konflikte zu vermeiden und das Potential der Heterogenität zu nutzen

Intraoperative measurement of arterial blood flow in aneurysm surgery

Intraoperative flowmetry (IF) has been recently introduced during cerebral aneurysm surgery in order to obtain a safer surgical exclusion of the aneurysm. This study evaluates the usefulness of IF during surgery for cerebral aneurysms and compares the results obtained in the joined surgical series of Verona and Padua to the more recent results obtained at the neurosurgical department of Verona. In the first surgical series, between 2001 and 2010, a total of 312 patients were submitted to IF during surgery for cerebral aneurysm at the neurosurgical departments of Verona and Padua: 162 patients presented with subarachnoid hemorrhage (SAH) whereas 150 patients harbored unruptured aneurysms. In the second series, between 2011 and 2016, 112 patients were submitted to IF during surgery for cerebral aneurysm at the neurosurgical department of Verona; 24 patients were admitted for SAH, whereas 88 patients were operated on for unruptured aneurysms. Comparison of the baseline values in the two surgical series and the baseline values between unruptured and ruptured aneurysms showed no statistical differences between the two clinical series. Analysis of flowmetry measurements showed three types of loco-regional flow derangements: hyperemia after temporary arterial occlusion, redistribution of flow in efferent vessels after clipping, and low flow in patients with SAH-related vasospasm. IF provides real-time data about flow derangements caused by surgical clipping of cerebral aneurysm, thus enabling the surgeon to obtain a safer exclusion; furthermore, it permits the evaluation of other effects of clipping on the loco-regional blood flow. It is suggested that\u2014in contribution with intraoperative neurophysiological monitoring\u2014IF may now constitute the most reliable tool for increasing safety in aneurysm surgery