Enhanced Hydrocarbons Biodegradation at Deep-Sea Hydrostatic Pressure with Microbial Electrochemical Snorkels

In anaerobic sediments, microbial degradation of petroleum hydrocarbons is limited by the rapid depletion of electron acceptors (e.g., ferric oxide, sulfate) and accumulation of toxic metabolites (e.g., sulfide, following sulfate reduction). Deep-sea sediments are increasingly impacted by oil contamination, and the elevated hydrostatic pressure (HP) they are subjected to represents an additional limitation for microbial metabolism. While the use of electrodes to support electrobioremediation in oil-contaminated sediments has been described, there is no evidence on their applicability for deep-sea sediments. Here, we tested a passive bioelectrochemical system named "oil-spill snorkel" with two crude oils carrying different alkane contents (4 vs. 15%), at increased or ambient HP (10 vs. 0.1 MPa). Snorkels enhanced alkanes biodegradation at both 10 and 0.1 MPa within only seven weeks, as compared to nonconductive glass controls. Microprofiles in anaerobic, contaminated sediments indicated that snorkels kept sulfide concentration to low titers. Bulk-sediment analysis confirmed that sulfide oxidation by snorkels largely regenerated sulfate. Hence, the sole application of snorkels could eliminate a toxicity factor and replenish a spent electron acceptor at increased HP. Both aspects are crucial for petroleum decontamination of the deep sea, a remote environment featured by low metabolic activity

Enhancing methane production from food waste fermentate using biochar. The added value of electrochemical testing in pre-selecting the most effective type of biochar

Background: Recent studies have suggested that addition of electrically conductive biochar particles is an effective strategy to improve the methanogenic conversion of waste organic substrates, by promoting syntrophic associations between acetogenic and methanogenic organisms based on interspecies electron transfer processes. However, the underlying fundamentals of the process are still largely speculative and, therefore, a priori identification, screening, and even design of suitable biochar materials for a given biotechnological process are not yet possible. Results: Here, three charcoal-like products (i.e., biochars) obtained from the pyrolysis of different lignocellulosic materials, (i.e., wheat bran pellets, coppiced woodlands, and orchard pruning) were tested for their capacity to enhance methane production from a food waste fermentate. In all biochar-supplemented (25 g/L) batch experiments, the complete methanogenic conversion of fermentate volatile fatty acids proceeded at a rate that was up to 5 times higher than that observed in the unamended (or sand-supplemented) controls. Fluorescent in situ hybridization analysis coupled with confocal laser scanning microscopy revealed an intimate association between archaea and bacteria around the biochar particles and provided a clear indication that biochar also shaped the composition of the microbial consortium. Based on the application of a suite of physico-chemical and electrochemical characterization techniques, we demonstrated that the positive effect of biochar is directly related to the electron-donating capacity (EDC) of the material, but is independent of its bulk electrical conductivity and specific surface area. The latter properties were all previously hypothesized to play a major role in the biochar-mediated interspecies electron transfer process in methanogenic consortia. Conclusions: Collectively, these results of this study suggest that for biochar addition in anaerobic digester operation, the screening and identification of the most suitable biochar material should be based on EDC determination, via simple electrochemical tests. © 2017 The Author(s)

Modal and nonmodal stability of a stably stratified boundary layer flow

The modal and nonmodal linear stability of a stably stratified Blasius boundary layer flow, composed of a velocity and a thermal boundary layer, is investigated. The temporal and spatial linear stability of such flow is investigated for several Richardson, Reynolds, and Prandtl numbers. While increasing the Richardson number stabilizes the flow, a more complex behavior is found when changing the Prandtl number, leading to a stabilization of the flow up to Pr = 7, followed by a destabilization. The nonmodal linear stability of the same flow is then investigated using a direct-adjoint procedure optimizing four different approximations of the energy norm based on a weighted sum of the kinetic and the potential energies. No matter the norm approximation, for short target times an increase of the Richardson number induces a decrease of the optimal energy gain and time at which it is obtained and an increase of the optimal streamwise wave number, which considerably departs from zero. Moreover, the dependence of the energy growth on the Reynolds number transitions from quadratic to linear, whereas the optimal time, which varies linearly with Re in the nonstratified case, remains constant. This suggests that the optimal energy growth mechanism arises from the joint effect of the lift-up and the Orr mechanism, that simultaneously act to increase the shear production term on a rather short timescale, counterbalancing the stabilizing effect of the buoyancy production term. Although these short-time mechanisms are found to be robust with respect to the chosen norm, a different amplification mechanism is observed for long target times for three of the proposed norms. This strong energy growth, due to the coupling between velocity and temperature perturbations in the free stream, disappears when the variation of the stratification strength with height is accurately taken into account in the definition of the norm

Minimal energy thresholds for sustained turbulent bands in channel flow

In this work, nonlinear variational optimization is used for obtaining minimal seeds for the formation of turbulent bands in channel flow. Using nonlinear optimization together with energy bisection, we have found that the minimal energy threshold for obtaining spatially patterned turbulence scales with$Re^{-8.5}$forRe>1000. The minimal seed, which is different to that found in a much smaller domain, is characterized by a spot-like structure surrounded by a low-amplitude large-scale quadrupolar flow filling the whole domain. This minimal-energy perturbation of the laminar flow has dominant wavelengths close to$4$in the streamwise direction and$1$in the spanwise direction, and is characterized by a spatial localization increasing with the Reynolds number. At$Re \lesssim 1200$, the minimal seed evolves in time, creating an isolated oblique band, whereas for$Re\gtrsim 1200$, a quasi-spanwise-symmetric evolution is observed, giving rise to two distinct bands. A similar evolution is found also at low$Re$for non-minimal optimal perturbations. This highlights two different mechanisms of formation of turbulent bands in channel flow, depending on the Reynolds number and initial energy of the perturbation. The selection of one of these two mechanisms appears to be dependent on the probability of decay of the newly created stripe, which increases with time, but decreases with the Reynolds number

Axillary Ectopic Carcinoma of the Breast. Report of Two Cases with Different Clinical Presentation and Review of the Literature.

Aims: Primary ectopic breast cancer (PEBC) is a rare and often misdiagnosed condition. Through the discussion of two clinical cases, we want to focus on clinical presentation, outcomes and treatment of PEBC, to lead clinicians to awareness and optimal management. Methods: We present the case of a 47-year-old patient, with a 30 mm axillary mass, that was diagnosed as a PEBC (infiltrating lobular carcinoma, triple negative). The patient underwent systemic staging: diffuse metastatic bone lesions and leptomeningeal metastasis were found. The second patient is a 73-year-old woman with personal history of right breast tumor. She came to our attention for a 9 mm left axillary mass, suspicious for a metastatic lymph node. A fine-needle cytology revealed the absence of lymphoid cells but the presence of atypical epithelial cells, as in a primary breast carcinoma. She was treated with local excision and sentinel node biopsy. Results: The first patient presented with metastatic disease at the time of diagnosis and she deceased after three months from the diagnosis, despite systemic chemotherapy. The diagnosis was performed at an early stage in the second patient. She underwent surgery, complementary endocrine therapy and radiotherapy. She has no evident disease after two years from surgery. Conclusion: Primary ectopic breast cancer is a rare clinical entity, often misdiagnosed or diagnosed with a long delay. The treatment of PEBC is analogous to that of orthotopic breast cancer, but we strongly recommend to approach the patient with a multidisciplinary team to provide the best staging workout and therapie

Management of PALB2-associated breast cancer: A literature review and case report

Key Clinical Message Germline pathogenic variants (PV) of the PALB2 tumor suppressor gene are associated with an increased risk of breast, pancreatic, and ovarian cancer. In previous research, PALB2-associated breast cancer showed aggressive clinicopathological phenotypes, particularly triple-negative subtype, and higher mortality regardless of tumor stage, type of chemotherapy nor hormone receptor status. The identification of this germline alteration may have an impact on clinical management of breast cancer (BC) from the surgical approach to the systemic treatment choice. We herein report the case of a patient with a germline PV of PALB2, diagnosed with locally advanced PD-L1 positive triple-negative BC, who progressed after an immune checkpoint inhibitor (ICI)-containing regimen and then experienced a pathologic complete response after platinum-based chemotherapy. This case report hints a major role of the germline PALB2 alteration compared to the PD-L1 expression as cancer driver and gives us the opportunity to extensively review and discuss the available literature on the optimal management of PALB2-associated BC. Overall, our case report and review of the literature provide additional evidence that the germline analysis of PALB2 gene should be included in routine genetic testing for predictive purposes and to refine treatment algorithms

Perceptions and experiences of a sample of nontraditional students in transition from Higher Education to the Labour Market in Western Sicily.

In recent years a long economic crisis has affected the occupational opportunities of young people. In Italy, unemployment among 20-34 year olds, reached percentage values as high as 40%. The purpose of this work was to investigate perceptions and expectations of a group of nontraditional students about to graduate in Western Sicily. A group of 200 nontraditional students (112F/88M) attending final year classes in four randomly selected university courses were interviewed using a 25 item questionnaire. The students selected were concerned about the post-graduation period, and all complained about the scarcity of employment opportunities in the south of Italy. Indeed, a distance remains between education, market dynamics and employers. Education to produce skilled graduates therefore becomes crucial and requires a new pathway derived from a better insight in the youth labour market

Serious games e autoregolazione a scuola: una sfida pedagogica nell'attuale panorama digitale

Il presente lavoro intende riflettere criticamente sul valore pedagogico-educativo dei serious games all’interno dei contesti scolastici, a partire dall’idea di una necessaria implementazione di ambienti di apprendimento supportati da strumenti digitali che possano promuovere competenze cognitive ed emotivo-relazionali, sostenendo la motivazione e la partecipazione degli studenti. In questa cornice, il contributo intende porre l’attenzione sugli interventi di promozione e innovazione delle nuove tecnologie nei contesti didattici e sui vantaggi dei serious games, attraverso un uso critico e autoregolato

Inclusive didactics and assistive technologies: the experience of a group of special needs teachers

This paper describes the results of an exploratory survey aimed to examine the experience and perceptions of a group of special needs teachers on the use of ICT in teaching to students with autism spectrum disorder. It is focused on the effectiveness of video modeling as a tool through which to learn (self-learning and imitation) specific skills in the field of personal autonomy. By sharing the thought of Rossi (2012) : ‹‹digital technologies provide to schools an extraordinary opportunity to put on the agenda the issue of learning and, together with it, the professionalism of teachers››. The authors handed out a questionnaire to a group of special needs teachers of a Comprehensive School in Palermo with the purpose to investigate the perceived effectiveness experienced in the use of ICT for the achievement of different learning objectives. This work offers a detailed analysis of the investigated areas and the results from the survey, proposing a critical reflection on information technology in teaching