Formulation and Characterization of an Antimicrobial Coating Containing Nisin for Large Scale Food Package Converting Processes

This research consisted of formulating an antimicrobial coating containing Nisaplin® intended for large scale production and inhibition of spoilage microorganisms. Secondly, the coating formulated was applied to a flexible film surface using two trials (gravure and flexography) commonly used in large scale food package coating or printing processes. In addition, diffusion and mass transfer theory was applied to discuss the many complications of predicting nisin diffusion or release from a coated material for antimicrobial food packaging applications. Previous work conducted by predecessors, produced an antimicrobial coating formulation using a 70/30 Methylcellulose/Hydroxypropyl methylcellulose base (MC/HPMC). Some disadvantages of this coating included haze, lack of sealability and percent solids content too low for large-scale gravure and/or flexographic coating application processes (which require 15-50% solids). Due to the characteristics, it was then determined that the coating would need to be re-formulated to maintain these qualities in addition to the ability to be up-scaled to large scale gravure and/or flexographic coating processes and lastly, maintain antimicrobial activity against desired microorganisms. Multiple materials were tested to determine the antimicrobial coating formulation including four grades of polyvinyl alcohol, plasticizers, emulsifiers and antimicrobials. The first set of testing, differential scanning calorimetry (DSC), was used to determine the melt temperature of the base or matrix for containing this nisin. It is important to determine the melt temperature of the resin in order to determine the sealability of the final package. DSC testing showed that 88% hydrolyzed, granular polyvinyl alcohol (Mowiol 4-88, Kuraray) resin combined with glycerin (40 phr) resulted in a decreased melt temperature from 189.7°C to 150.9°C and decreased thermal degradation via hydrolysis. These two components were determined to be part of the film forming matrix due to the potential for sealability. Dynamic contact angle testing was also utilized to determine adhesion, critical surface tension to several substrates (LLDPE coex, Bynel®2002; Elvax® 3165, Nucrel® 1202 HC and Surlyn® 1605) and wettability of the coating solution. All substrates were found to have statistically significantly different critical surface tensions from the control LLDPE substrate (ɑ = 0.05). All substrates except for corona treated Elvax® and Surlyn® were found to have statistically significantly different dynamic contact angle measurements from the control LLDPE substrate (ɑ = 0.05) (p value = 0.1231, Elvax® – corona; p value = 0.5648, Surlyn® - corona). Tape tests were conducted to select the final coating substrate, LLDPE. All of the testing parameters (pH, percent solids, melt temperature) indicated that the formulation was suitable for gravure or flexography coating applications. Coating trials using the formulated antimicrobial coating showed the potential for implementing a coating containing nisin on large scale production processes. Gravure and flexography trials were conducted on primed and corona treated LLDPE material. Several characteristics of the liquid coating and dried, coated substrate were tested for quality and overall specifications such as pH, percent solids and blocking. Film on lawn testing indicated that treatment films coated using both processes were able to inhibit Micrococcus luteus compared to control films (Gravure: P\u3c0.0001; Flexography: P\u3c0.0001). This study showed that the formulated coating had potential to be produced using large scale food package converting processes while maintaining antimicrobial efficacy against a food spoilage indicator bacterium. Mass transfer of antimicrobial components in antimicrobial packaging systems are governed by numerous variables both extrinsic and intrinsic factors. This study provided literature review and mass transfer theory to predict the diffusion or controlled release of nisin from the produced packaging system to target microorganisms on a food product. Factors such polymer structure, temperature, food product, fat content and polymer swellability and their effects of diffusion and controlled release were discussed. This study showed that antimicrobial packaging systems are complicated multivariable systems that require many assumptions in order to make diffusion prediction mathematically feasible. The original work conducted by Franklin et al (2004) that this project was based off of was intended for frankfurters. The intended market of the produced antimicrobial film was for ready-to-eat (RTE) foods. These types of foods are those which do not need to be cooked prior to consumption. Due to the rising demand for convenient food products such as RTE foods, this material could be implemented for usage against surface contamination and spoilage microorganisms

An X-ray/SDSS sample (II): outflowing gas plasma properties

Galaxy-scale outflows are nowadays observed in many active galactic nuclei (AGNs); however, their characterisation in terms of (multi-) phase nature, amount of flowing material, effects on the host galaxy, is still unsettled. In particular, ionized gas mass outflow rate and related energetics are still affected by many sources of uncertainties. In this respect, outflowing gas plasma conditions, being largely unknown, play a crucial role. Taking advantage of the spectroscopic analysis results we obtained studying the X-ray/SDSS sample of 563 AGNs at z $<0.8$ presented in our companion paper, we analyse stacked spectra and sub-samples of sources with high signal-to-noise temperature- and density-sensitive emission lines to derive the plasma properties of the outflowing ionized gas component. For these sources, we also study in detail various diagnostic diagrams to infer information about outflowing gas ionization mechanisms. We derive, for the first time, median values for electron temperature and density of outflowing gas from medium-size samples ($\sim 30$ targets) and stacked spectra of AGNs. Evidences of shock excitation are found for outflowing gas. We measure electron temperatures of the order of $\sim 1.7\times10^4$ K and densities of $\sim 1200$ cm$^{-3}$ for faint and moderately luminous AGNs (intrinsic X-ray luminosity $40.5<log(L_X)<44$ in the 2-10 keV band). We caution that the usually assumed electron density ($N_e=100$ cm$^{-3}$) in ejected material might result in relevant overestimates of flow mass rates and energetics and, as a consequence, of the effects of AGN-driven outflows on the host galaxy.Comment: 16 pages, 10 figures. Accepted for publication in A&

Starbursting to Quenching: the Role of X-Ray Emission in Active Galactic Nuclei Feedback Processes.

One of the most debated topics of modern extragalactic astrophysics is the co-evolution between the SMBHs sitting in the nuclei of the galaxies and their hosts. According to the most popular models of AGN and galaxies co-evolution, starburst galaxies, unobscured quasars and inactive (and quenched) galaxies represent the different phases of an evolutionary sequence reproducing the most massive galaxies observed in the Universe. In this context, gas flows in the form of energetic outflows are postulated to play a pivotal role in this process, given that they regulate both accretion and ejection of material onto and from the SMBH, acting on the fuel from which new stars form and stopping the host galaxy growth. In order to validate this AGN-galaxy binding nature, we investigate the kinematic and physical properties of ionized and atomic gas components of the ISM of well selected AGN-galaxy systems, obtained from ultraviolet, optical, near-infrared spectroscopic analysis, to unveil the presence of outflows. In particular, we propose and test different selection criteria to isolate sources at z ~2 in the predicted feedback phase, starting from multiwavelength information collected in the COSMOS field. As a complementary approach, we also collect a large sample of X-ray selected AGNs at z < 0.8 from the SDSS database to unveil the incidence of outflows and prove the crucial role of X-ray observations for the investigation of the feedback phase. We combine the ionized/neutral gas kinematic and physical conditions with SMBH accretion and host galaxy properties, recovered from multiwavelength spectral energy distribution analysis and X-ray spectroscopic investigation, to infer the general conditions regulating the feedback processes. We also discuss our results in the context of the more recent observational and theoretical clues

Multi-phase outflows in Mkn 848 observed with SDSS-MaNGA Integral Field Spectroscopy

The characterisation of galaxy-scale outflows in terms of their multi-phase nature, amount, and effects of flowing material is crucial to place constraints on models of galaxy evolution. This study can proceed only with the detailed investigation of individual targets. We present a spatially resolved spectroscopic optical data analysis of Mkn 848, a complex system consisting of two merging galaxies at z~0.04 that are separated 7.5 kpc (projected distance). Motivated by the presence of a multi-phase outflow in the north-west system revealed by the SDSS integrated spectrum, we analysed the publicly available MaNGA data, which cover almost the entire merging system, to study the physical properties of cool and warm gas in detail. Galaxy-wide outflowing gas in multiple phases is revealed for the first time in the two merging galaxies. We also detect spatially resolved resonant NaID emission associated with the outflows. The derived outflow energetics may be consistent with a scenario in which both winds are accelerated by stellar processes and AGN activity, although we favour an AGN origin given the high outflow velocities and the ionisation conditions observed in the outflow regions. Deeper observations are required, however, to better constrain the nature of these multi-phase outflows. Outflow energetics in the north-west system are strongly different between the ionised and atomic gas components, the latter of which is associated with mass outflow rate and kinetic and momentum powers that are 1-2 dex higher; those associated with the south-east galaxy are instead similar. Strong kp-scale outflows are revealed in an ongoing merger system, suggesting that feedback can potentially impact the host galaxy even in the early merger phases. The characterisation of the neutral and ionised gas phases has proved to be crucial for a comprehensive study of the outflow phenomena.Comment: 19 pages, 14 figures, accepted for publication in A&

Teacher education in portuguese as an additional language: moving beyond communicative theories and towards critical intercultural pedagogies

Este relatório apresenta os resultados de um projeto de pesquisa no nível de pós-doutorado que culminou no desenvolvimento de um curso de uma especialização lato sensu em docência de Português como Língua Adicional (PLA). As seguintes questões norteadoras guiaram esse projeto: (1) quais são as fundamentações teórico-pedagógicas que informam a formação de professores de PLA e outras línguas adicionais (LAs)? e (2) quais são os principais critérios para a escolha daquelas fundamentações? Doze professores de seis instituições de ensino superior ministrando disciplinas relacionadas ao estágio docente obrigatório de línguas adicionais responderam um questionário. A análise das respostas demonstrou que (1) as abordagens comunicativas informam a formação de professores de LAs; e (2) o efeito retroativo contribui para a adoção de tais abordagens. As abordagens comunicativas, por servirem de base a vários exames de proficiência, têm informado a formação de professores de LAs. Construtos teórico-pedagógicos interculturais e críticos, mais recentemente aplicados ao campo da educação de LAs, questionam as abordagens comunicativas e atualizam as noções de língua, linguagem, competência e cultura. Propõe-se uma educação formadora e problematizadora contrária às hegemonias e aos estereótipos socioculturais, mas favorável ao empoderamento, à emancipação e à cidadania intercultural, cosmopolita e democrática. Desenvolvemos, então, um curso de formação para professores de PLA que promove, através de experiências pedagógicas, diversas representações, interpretações, expectativas, memórias e identificações culturais dos envolvidos no processo de ensino-aprendizagem enquanto a língua alvo é usada para (re)produzir, (re)negociar e (re)construir identidades socioculturais.This report presents the results of a postdoctoral research project which culminated in the development of a lato sensu postgraduate course in Portuguese as an Additional Language Teacher Education. The following research questions guided the project: (1) which theoretical and pedagogical perspectives inform programmes for teacher education in Portuguese as an Additional Language (PAL) and other Additional Languages (ALs)?; and (2) which criteria are used to justify such perspectives? Twelve professors from six higher education institutions who serve as instructors for disciplines related to mandatory internship in ALs responded to an online survey. Analysis of their responses demonstrated that (1) communicative approaches inform additional language teacher education; and (2) washback effect is a strong factor which contributes for the adoption of such approaches. Communicative approaches, for informing several proficiency exams, have been used as the main or sole theoretical and/or pedagogical construct on which teacher education in ALs is based. Recently applied to ALs teaching and learning, critical and intercultural pedagogies question communicative approaches and update notions of language, language use, competence, and culture. In so doing, emancipatory education problematises sociocultural hegemonies and stereotypes while encouraging social agency, empowerment, and intercultural, cosmopolitan and democratic citizenship. Thus, we developed a PAL teacher education course which promotes diverse cultural representations, interpretations, expectations, memories and identifications of those participating in the teaching-learning processes throughout pedagogical experiences. Meanwhile, the target language is used to (re)produce, (re)negotiate, and (re)build sociocultural identities

Alexithymia and Suicide Risk in Psychiatric Disorders: A Mini-Review.

It is well known that alexithymic individuals may show significantly higher levels of anxiety, depression, and psychological suffering than non-alexithymics. There is an increasing evidence that alexithymia may be considered a risk factor for suicide, even simply increasing the risk of development of depressive symptoms or per se. Therefore, the purpose of this narrative mini-review was to elucidate a possible relationship between alexithymia and suicide risk. The majority of reviewed studies pointed out a relationship between alexithymia and an increased suicide risk. In several studies, this relationship was mediated by depressive symptoms. In conclusion, the importance of alexithymia screening in everyday clinical practice and the evaluation of clinical correlates of alexithymic traits should be integral parts of all disease management programs and, especially, of suicide prevention plans and interventions. However, limitations of studies are discussed and must be considered

BK Virus Infection and BK-Virus-Associated Nephropathy in Renal Transplant Recipients

Poliomavirus BK virus (BKV) is highly infective, causing asymptomatic infections during childhood. After the initial infection, a stable state of latent infection is recognized in kidney tubular cells and the uroepithelium with negligible clinical consequences. BKV is an important risk factor for BKV-associated diseases, and, in particular, for BKV-associated nephropathy (BKVN) in renal transplanted recipients (RTRs). BKVN affects up to 10% of renal transplanted recipients, and results in graft loss in up to 50% of those affected. Unfortunately, treatments for BK virus infection are restricted, and there is no efficient prophylaxis. In addition, consequent immunosuppressive therapy reduction contributes to immune rejection. Increasing surveillance and early diagnosis based upon easy and rapid analyses are resulting in more beneficial outcomes. In this report, the current status and perspectives in the diagnosis and treatment of BKV in RTRs are reviewed