Intermittent aeration to regulate microbial activities in membrane-aerated biofilm reactors: energy-efficient nitrogen removal and low nitrous oxide emission

autotrophic nitrogen removal, yet control of nitrogen turnover remains challenging in MABR counter-diffusion biofilms. In this study, we regulated microbial activities in two lab-scale MABRs by providing continuous versus intermittent aeration. Nitrogen consumption by different functional microbial groups was estimated from bulk measurements via a mass balance approach. Nitrite-oxidizing bacteria (NOB) proliferated under continuous aeration while they were significantly suppressed under intermittent aeration, and NOB suppression activated anaerobic ammonium oxidation. Nitritation performance in the MABR was studied through long-term bulk measurements and in situ biofilm microprofiles of dissolved oxygen (DO) and pH. During intermittent aeration pH effects rather than DO effects determined nitritation success, especially ammonia speciation, which serves as substrate and inhibitor in nitrification processes. Biofilm transition phases were monitored upon aeration switches. Canonical correspondence analysis suggested that the relative transition after anoxia and aeration intermittency were less decisive for biofilm performance than the relative aeration duration. Heterotrophic bacteria displayed minor denitrification rates with aeration control, but contributed to mitigation of nitrous oxide (N2O) emissions. N2O production hotspots were identified at the top of the anoxic biofilm zone under continuous aeration. Instead, under intermittent aeration an anoxic N2O reduction zone was established. Our observations support intermittent aeration control of MABRs as a simple strategy for energy-efficient nitrogen removal with low N2O emission

Patient expression of emotions and neurologist responses in first multiple sclerosis consultations

Background: Anxiety and depression are common in people with multiple sclerosis (MS), but data on emotional communication during MS consultations are lacking. We assessed patient expressions of emotion and neurologist responses during first-ever MS consultations using the Verona Coding Definitions of Emotional Sequences (VR-CoDES). Methods: We applied VR-CoDES to recordings/transcripts of 88 outpatient consultations (10 neurologists, four MS Italian centers). Before consultation, patients completed the Hospital Anxiety and Depression Scale (HADS). Multilevel sequential analysis was performed on the number of cues/concerns expressed by patients, and the proportion of reduce space responses by neurologists. Results: Patients expressed 492 cues and 45 concerns (median 4 cues and 1 concern per consultation). The commonest cues were verbal hints of hidden worries (cue type b, 41%) and references to stressful life events (type d, 26%). Variables independently associated with number of cues/concerns were: anxiety (HADS-Anxiety score >8) (incidence risk ratio, IRR 1.08, 95% CI 1.06-1.09; p<0.001); patient age (IRR 0.98, 95% CI 0.98-0.99; p<0.001); neurologist age (IRR 0.94, 95% CI 0.92-0.96; p=0.03); and second opinion consultation (IRR 0.72, 95% CI 0.60-0.86; p=0.007). Neurologists reacted to patient emotions by reducing space (changing subject, taking no notice, giving medical advice) for 58% of cues and 76% of concerns. Anxiety was the only variable significantly associated with 'reduce space' responses (odds ratio 2.17, 95% CI 1.32-3.57; p=0.003). Conclusions: Patient emotional expressions varied widely, but VR-CoDES cues b and d were expressed most often. Patient anxiety was directly associated with emotional expressions; older age of patients and neurologists, and second opinion consultations were inversely associated with patient emotional expression. In over 50% of instances, neurologists responded to these expressions by reducing space, more so in anxious patients. These findings suggest that neurologists need to improve their skills in dealing with patient emotions

Genetic structure and phylogeography of pine shoot beetle populations (Tomicus destruens and T. piniperda, Coleoptera Scolytidae) in Italy

Tomicus are among the most dangerous pine pests. In this paper we assess the genetic structure of some Italian Tomicus populations, and the possible sympatry of T. destruens and T. piniperda. A fragment 358 bp long of the mitochondrial DNA relative to the COI was investigated in eight populations by SSCP analyses and sequencing. In the sampled populations T. destruens and T. piniperda were not found to be sympatric. T. destruens populations of southern and central Italy strongly differ from a population of northern Italy. The phylogeographic analysis of T. destruens populations in Europe is geographically structured, probably due to the fragmentation of the host pine ranges. The populations of T. piniperda are polymorphic, with haplotypes occurring also in Europe and Asia. T. piniperda populations seem to be genetically unstructured because of both the continuous distribution area of its main host (Pinus sylvestris) and the international trade of pine timber.Structure génétique et phylogéographie des populations de Tomicus destruens et T. piniperda (Coleoptera Scolytidae) en Italie. Le genre Tomicus figure parmi les espèces les plus dangereuses pour les forêts de pins. La structure génétique de huit populations italiennes de T. destruens et T. piniperda a été étudiée, ainsi que la sympatrie possible des deux espèces. Un fragment de 358 pb de l’ADN mitochondrial relatif au COI a été amplifié, séquencé et soumis à une analyse par SSCP. Aucun cas de sympatrie n’a été observé entre T. destruens et T. piniperda. Les populations de T. destruens d’Italie méridionale et centrale sont très différentes d’une population d’Italie du Nord. T. destruens montre une structuration géographique probablement liée à la distribution fragmentée des pins hôtes. Par contre, les populations de T. piniperda sont très polymorphes, sans doute à cause de la distribution continue de son principal hôte, le pin sylvestre, ainsi qu’au commerce international de bois

Presence of specific symbiotic bacteria in flies of the subfamily Tephritinae (Diptera Tephritidae) and their phylogenetic relationships: proposal of "Candidatus Stammerula tephritidis"

The presence of symbiotic bacteria in flies belonging to the subfamily Tephritinae, which predominantly infest the flower heads of composite flowers (Asteraceae), was investigated. Twenty-five species of flies, collected mainly in northern Italy, were examined. The bacteria adhered to the midgut epithelium in a space external to the peritrophic membrane and therefore not in direct contact with the gut contents. Specific, unique and live, but unculturable bacteria were consistently found in the majority of the fly species and their presence was also shown to be persistent in flies reared under microbiologically controlled conditions and devoid of any residual culturable intestinal bacteria. Sequencing of the small subunit rRNA gene from the novel bacteria indicated that they belonged to the family Enterobacteriaceae. Three main strongly supported clades were delineated by phylogenetic trees, the first of which featured a coherent set of sequences displaying gene sequence similarities lower than 96 % compared with recognized taxa. The second and third clades featured cases with higher gene sequence similarities to culturable bacteria, including Erwinia persicina and Ewingella americana, respectively. Relative rate tests were supportive of a fast genetic evolution for the majority of the bacterial symbionts of the subfamily Tephritinae. In agreement with the interpretation suggested in 1929 after pioneering observations made by H. J. Stammer, a symbiotic relationship between the novel bacteria and the tephritid flies is postulated. The origin of this apparently polyphyletic relationship is discussed and a novel candidate organism is proposed for the first clade under the designation ‘Candidatus Stammerula tephritidis’