Skin Lesion Segmentation Using Image Bit-Plane Multilayer Approach

The establishment of automatic diagnostic systems able to detect and classify skin lesions at the initial stage are getting really relevant and effective in providing support for medical personnel during clinical assessment. Image segmentation has a determinant part in computer-aided skin lesion diagnosis pipeline because it makes possible to extract and highlight information on lesion contour texture as, for example, skewness and area unevenness. However, artifacts, low contrast, indistinct boundaries, and different shapes and areas contribute to make skin lesion segmentation a challenging task. In this paper, a fully automatic computer-aided system for skin lesion segmentation in dermoscopic images is indicated. Adopting this method, noise and artifacts are initially reduced by the singular value decomposition; afterward lesion decomposition into a frame of bit-plane layers is performed. A specific procedure is implemented for redundant data reduction using simple Boolean operators. Since lesion and background are rarely homogeneous regions, the obtained segmentation region could contain some disjointed areas classified as lesion. To obtain a single zone classified as lesion avoiding spurious pixels or holes inside the image under test, mathematical morphological techniques are implemented. The performance obtained highlights the method validit

Acetic acid stress in budding yeast: From molecular mechanisms to applications

Acetic acid stress represents a frequent challenge to counteract for yeast cells under several environmental conditions and industrial bioprocesses. The molecular mechanisms underlying its response have been mostly elucidated in the budding yeast Saccharomyces cerevisiae, where acetic acid can be either a physiological substrate or a stressor. This review will focus on acetic acid stress and its response in the context of cellular transport, pH homeostasis, metabolism and stress-signalling pathways. This information has been integrated with the results obtained by multi-omics, synthetic biology and metabolic engineering approaches aimed to identify major cellular players involved in acetic acid tolerance. In the production of biofuels and renewable chemicals from lignocellulosic biomass, the improvement of acetic acid tolerance is a key factor. In this view, how this knowledge could be used to contribute to the development and competitiveness of yeast cell factories for sustainable applications will be also discussed

Iterative complex network approach for chemical gas sensor array characterisation

Gas sensor arrays, also known as e-noses, are used in several heterogeneous fields, ranging from environmental monitoring to food quality control. Often, these measurement systems operate within dynamic environments and are subject to conditions which may dramatically vary over time. Furthermore, the response of an e-nose is influenced by several parameters, whose interactions may be complex and highly non-linear. Therefore, in this study, the authors propose a complex network approach to model the overall interaction pattern of e-noses. They show that this approach can significantly improve the understanding of the overall behaviour of e-noses, and can be used as a basis to optimise the design of these measurement systems

Galileo e Le lettere solari

Una riflessione sullo stile di pensiero e sulle scelte linguistiche di Galileo potrebbe significativamente prendere avvio da un singolare scambio epistolare iniziato nel 1612, che vede come protagonisti Marco Welser, duumviro di Augusta, Cristoph Scheiner, professore di matematica all’Università di Ingolstadt, e, naturalmente, Galileo, che Welser aveva conosciuto quando «gli [a Galileo] aveva sottoposto alcuni dubbi […] circa la montuosità della luna». Le forme e i tempi di una conversazione a distanza tra Welser, Scheiner e Galilei si iscrivono in una tipologia di discorso inteso a muovere gli interlocutori intorno a un tema astronomico quale era quello delle macchie solari, passando attraverso il fervente dibattito sulla “nuova scienza” di cui, particolarmente a Venezia e a Padova, erano promotori, oltre a Galilei, anche Paolo Sarpi e Santorio Santorio. Il dibattito a distanza di Galileo con Welser e in particolare con Scheiner non manca di toni aspri, a volte polemici: questo stesso dibattito si pone come prologo della riflessione galileiana consegnata a opere come Il Saggiatore e il Dialogo sopra i due massimi sistemi del mondo

Plasmodium falciparum metacaspase PfMCA-1 triggers a z-VAD-fmk inhibitable protease to promote cell death.

Activation of proteolytic cell death pathways may circumvent drug resistance in deadly protozoan parasites such as Plasmodium falciparum and Leishmania. To this end, it is important to define the cell death pathway(s) in parasites and thus characterize proteases such as metacaspases (MCA), which have been reported to induce cell death in plants and Leishmania parasites. We, therefore, investigated whether the cell death function of MCA is conserved in different protozoan parasite species such as Plasmodium falciparum and Leishmania major, focusing on the substrate specificity and functional role in cell survival as compared to Saccharomyces cerevisae. Our results show that, similarly to Leishmania, Plasmodium MCA exhibits a calcium-dependent, arginine-specific protease activity and its expression in yeast induced growth inhibition as well as an 82% increase in cell death under oxidative stress, a situation encountered by parasites during the host or when exposed to drugs such as artemisins. Furthermore, we show that MCA cell death pathways in both Plasmodium and Leishmania, involve a z-VAD-fmk inhibitable protease. Our data provide evidence that MCA from both Leishmania and Plasmodium falciparum is able to induce cell death in stress conditions, where it specifically activates a downstream enzyme as part of a cell death pathway. This enzymatic activity is also induced by the antimalarial drug chloroquine in erythrocytic stages of Plasmodium falciparum. Interestingly, we found that blocking parasite cell death influences their drug sensitivity, a result which could be used to create therapeutic strategies that by-pass drug resistance mechanisms by acting directly on the innate pathways of protozoan cell death