Catalysis by alkali and alkaline-earth metal ions in nucleophilic attack of methoxide ion on crown ethers bearing an intra-annular acetoxy group

Rates of reaction of methoxide ion with crown ethers bearing an intra-annular acetoxy group are markedly enhanced by alkali and alkaline-earth metal bromides as a result of much stronger interactions of the metal ions with transition states than with reactants.\ud \ud Rates of reactions of methoxide ion with crown ethers bearing an intra-annular acetoxy group markedly enhanced by alkali and alkaline-earth metal bromides as a result of much stronger interactions of the metal ion with transition state than with reactants

Softening and instability of natural slopes in highly fissured plastic clay shales

International audienceSoftening is often considered to be the main cause of first-time slides in OC clay, but so far the mechanics of softening has not been satisfactorily explained. Bearing on laboratory data and field observations about landslides in tectonized highly plastic clay shales of Italian Apennines, the paper describes a process of soil weakening that could explain some failures of natural slopes

Analysis of human behavior in everyday life's contexts, for the development of new technologies, in support of the improvement of life quality and well-being.

The research has focused on aspects that have a direct impact on Indoor Environmental Quality, that are linked with the concept of comfort and are related to different aspects of human behavior in everyday life\u2019s contexts. The research question is \u201cIs it possible to create the right comfort, minimizing the user's activity when he/she is searching for it?\u201d We focused on temperature and, in this regard, we built a checklist that can help collecting data about the different reactions a user has when feeling uncomfortable with the indoor environment around him/her. We collected n.280 checklists in various indoor environments until now. In view of Ambient Assisted Living, we contacted n.5 health-care structures. We are doing observations through the checklist, to collect data about reactions on temperature, light, etc. and we are conducting interviews with professional experts. We collected n.58 checklists and n.21 interviews until now. The research is still underway

A new three object triangulation algorithm based on the power center of three circles

peer reviewedaudience: researcher, professional, popularizationPositioning is a fundamental issue in mobile robot applications that can be achieved in multiple ways. Among these methods, triangulation is a proven technique. As it exists for a long time, many variants of triangulation have been proposed. Which variant is most appropriate depends on the application because some methods ignore the beacon ordering while other have blind spots. Some methods are reliable but at a price of increasing complexity or special cases study. In this paper, we present a simple and new three object triangulation algorithm. Our algorithm works in the whole plane (except when the beacons and the robot are concyclic or colinear), and for any beacon ordering. Moreover, it does not need special cases study and has a strong geometrical meaning. Benchmarks show that our algorithm is faster than existing and comparable algorithms. Finally, a quality measure is intrinsically derived for the triangulation result in the whole plane, which can be used to identify the pathological cases, or as a validation gate in Kalman filters

Breakdown of keratin-laden biomass waste by the thermophilic bacterium Fervidobacterium pennivorans strain T

Developing a more sustainable agro-industry has become a necessity in light of the current environmental crisis. Biocatalysts are already adopted in many industrial applications and have quickly optimized, and in some cases replaced, existing biochemical reactions within the modern agro-industry. Extremozymes, in particular, are valuable tools for processes requiring harsh industrial conditions where, for example, increased temperature may be beneficial for the bioavailability and solubility of organic compounds as well as for improvement in degradation of substrates. In this regard, alternatives to landfill disposal or incineration of keratinous materials such as feathers, wool, hides, hair etc. are emerging and efforts in exploiting thermo-stable keratinolytic biocatalysts have been attempted. Nonetheless, keratin degradation remains a complex process poorly understood and thus limiting the current toolbox of useful enzymes and organisms needed to meet all demands. In this study, a newly isolated strain of an anaerobic, thermophilic microorganism belonging to the Thermotogae phylum, Fervidobacterium pennivorans strain T, was assessed for its capability of degrading native chicken feathers. By following a multiomics approach, its proteolytic system was explored in the attempt to isolate new keratinase candidates. First, the physiology of F. pennivorans strain T was further investigated in batch cultures and the first growth curve of an organism of this species was described, showing a generation time of 150 minutes and a long stationary phase. Then, the complete genome of the organism was sequenced and analysed, revealing interesting molecular features, such as inverted genomic blocks, when compared to its most closely related organisms: F. pennivorans DSM9078T and F. islandicum AW-1. The strain T genome was slightly shorter (2002515 base pair) and had ANI values of 97.65 % and 80.90% to the compared organisms, respectively, but the same number of predicted protease-encoding genes (55) were found by gene mining analysis. Next, feather degradation by the organism was up-scaled using a bioreactor to further evaluate its potential in industrial applications and cells were sampled for transcriptomics purposes. F. pennivorans strain T performed mediocrely in the fermenter, but RNA extraction was, however, not successful. From secretomics analysis of growing cultures, an extracellular serine protease named Peg_1025 was identified, showing high sequence conservation with the subtilisin type proteases, especially with subtilisin Ak1 from Geobacillus stearothermophilus strain AK1. By multiple sequencing alignment, the catalytic triad His, Asp, Ser, as well as a signal peptide and a propeptide domain were predicted. Three dimensional structural modelling using subtilisin Ak1 as template, showed Peg_1025 to possess several insertions of unknown functions compared to subtilisin Ak1, only one conserved Ca2+ binding site as well as lack of a disulphide bond in the active cleft. Nonetheless, important structural motifs remained conserved. The enzyme was successfully expressed in E. coli using N- and C-terminal His-tag and soluble proteins were active at 70°C in proteolytic activity assays that used casein as substrate. Phylogenetic analyses revealed that Peg_1025 belongs to a distinct clade of Thermotogae peptidases separated from fervidolysin and Ak1, and as such, it represents the first characterized member of this phylogenetic group. Although the specific role of the serine protease in feather degradation remains unclear, the general results from this study confirm that F. pennivorans strain T possesses a complex machinery with keratinolytic power. The biology of this extremophile remains an intriguing field of exploration, further encouraged by its biotechnological potential that is still left to unfold.Master's Thesis in BiologyBIO399MAMN-BI

Bioartificial scaffolds fabrication and their use for in vitro testing of wound healing devices

In the last decades Negative Pressure Wound Therapy (NPWT) has shown its efficacy in wound healing, applying continuous or intermittent subatmospheric pressure to the wound surface by means of dressing systems. While there is general consensus that positive effects originate from a complex interplay of mechanisms such as deformations and exudate removal, uncertainty persists about the optimal mode of application and the consequences of this therapy at a cellular level. A better understanding of the skin mechanobiology in response to therapeutic stimuli using a bioreactor system can help to individualize future wound therapies in a reproducible and controlled environment. This thesis proposed the fabrication of in vitro 3D skin models aiming to reproduce the relationship that occurs between cell types and skin substrate and investigated their use in a bioreactor in order to obtain new knowledge of NPWT mechanisms. Freeze-drying and electrospinning were considered to be the best methodologies to obtain homogenous and standardized 3D structures that were favourable for the purpose. Highly porous pure collagen and collagen-based scaffolds were firstly created using the freeze-drying technique. Various cross-linking methods were assessed and directly compared to establish the most suitable to improve mechanical stability and physical properties. Meanwhile, fibrous structures that could resemble the topography of the extra cellular matrix (ECM) were produced with the electrospinning system using toxic-free solutions and an in-house-developed rotating collector. The prospect to fabricate a hybrid bilayer scaffold, combining the two techniques was also investigated and discussed. Primary human skin fibroblasts were cultured on these structures and cell interaction and viability were evaluated through assays and microscopy techniques. Lastly, a proof-of-concept bioreactor for NPWT investigation was designed and tested on the freeze-dried scaffolds demonstrating the feasibility of this research approach. Results showed that blending methodology used in the freeze-drying can lead to scaffolds with unique physical properties while cross-linking has influence on substrate stiffness that guides cell response. With regard to the electrospinning, the use of the rotating collector was found to be promising in obtaining a bimodal fibre distribution resulting in porous and orientated membranes that simulate the orientation of collagen fibres in the dermis of human skin and could be beneficial for cell infiltration.To conclude, this study laid the groundwork for further development of these bioartificial scaffolds with improved properties that could be used as skin models and combined in a negative-pressure cell culture system with the aim to advance the understanding of NPWT biological mechanism and its clinical efficacy

Grown up boyz and girlz. Italian graphic novelists’ trans-European paths and gendered representations

Encouraged by a growing tendency towards international training and education as well as by the precarity that dominates artistic production in Italy, Italian comics artists are the protagonists of a diaspora as they emigrate to other European countries. This article investigates the effects of migration and geographical in-betweenness on the work of two Italian graphic novelists, Nicoz Balboa and Alice Socal, whose texts feature explicitly gendered representations. A hybrid methodology is employed, combining textual analysis supported by a nomadic feminist theoretical framework with semi-structured interviews with the authors. The article argues that Balboa and Socal inhabit a ‘diasporic space’ both as artists and individuals. This space is characterised by the constant contestation of socio-cultural boundaries and divisions. Furthermore, the gendered representations delineated by these authors systematically interrogate the inflexible binarisms imposed by the patriarchal socio-cultural order. These interrogations extend beyond gender boundaries, challenging the rigid dichotomy that separates youth from adulthood.This work is supported by national funds through FCT – Fundação para a Ciência e a Tecnologia, I.P., under the project [UIDB/00736/2020] (base funding) and [UIDP/00736/2020] (programmatic funding)

Re-appropriating abjection: feminism, comics, and the macabre coming-of-age

Julia Kristeva’s theories on the abject have proven fruitful for feminist criticism, which has produced a huge body of research on the representation of motherhood and femininity as macabre. More recently, the concept of abjection has been blamed for supposedly legitimising, instead of questioning, hetero-patriarchal erasure of women’s subjectivity. Despite this theoretical controversy, a growing number of comics and graphic novels, where the abject is used as a technique to illustrate the formation of women and girls’ gendered identity, have been published in the last decade. This article contends that the study of graphic narratives that are concerned with a macabre coming-of-age is a crucial site for the re-appropriation of abjection. This position sees abjection as a productive critical category that reflects an ongoing effort by feminist authors to portray the troubled construction of a female Self. To corroborate this idea, the article engages with previous scholarly close readings of comics/graphic novels on girlhood and the macabre. Further recognition of the fecundity of the abject category in the realm of graphic narratives is guaranteed by the in-depth analysis of the comic zine Fundo do nada (2017), by the Portuguese artist Ana Caspão. This comic zine, which has been so far ignored by critics, serves as case study given its ability to describe, by means of the medium-specific features of comics, a young woman’s coming-of-age, in which the abject functions as a tool to express the disquieting process of negotiating subjectivity from a feminine positioning.This work is supported by national funds through FCT – Fundação para a Ciência e a Tecnologia, I.P., under the project UIDB/00736/2020 (base funding) and UIDP/00736/2020 (programmatic funding)