Increasing the Fine Structure Visibility of the Hinode SOT Ca II H Filtergrams

We present the improved so-called Madmax (OMC) operator selecting maxima of convexities computed in multiple directions around each pixel rewritten in MatLab and shown to be very efficient for pattern recognition. The aim of the algorithm is to trace the bright hair-like features (for ex. chromospheric thin jets or spicules) of solar ultimate observations polluted by a noise of different origins. This popular spatial operator uses the second derivative in the optimally selected direction for which its absolute value has a maximum value. Accordingly, it uses the positivity of the resulting intensity signal affected by a superposed noise. The results are illustrated using a test artificially generated image and real SOT (Hinode) images are also used, to make your own choice of the sensitive parameters to use in improving the visibility of images.Comment: 12 pages, 3 figurs, submitted in Solar Physic

Evidence for the Role of Horizontal Transfer in Generating pVT1, a Large Mosaic Conjugative Plasmid from the Clam Pathogen, Vibrio tapetis

The marine bacterium Vibrio tapetis is the causative agent of the brown ring disease, which affects the clam Ruditapes philippinarum and causes heavy economic losses in North of Europe and in Eastern Asia. Further characterization of V. tapetis isolates showed that all the investigated strains harbored at least one large plasmid. We determined the sequence of the 82,266 bp plasmid pVT1 from the CECT4600T reference strain and analyzed its genetic content. pVT1 is a mosaic plasmid closely related to several conjugative plasmids isolated from Vibrio vulnificus strains and was shown to be itself conjugative in Vibrios. In addition, it contains DNA regions that have similarity with several other plasmids from marine bacteria (Vibrio sp., Shewanella sp., Listonella anguillarum and Photobacterium profundum). pVT1 contains a number of mobile elements, including twelve Insertion Sequences or inactivated IS genes and an RS1 phage element related to the CTXphi phage of V. cholerae. The genetic organization of pVT1 underscores an important role of horizontal gene transfer through conjugative plasmid shuffling and transposition events in the acquisition of new genetic resources and in generating the pVT1 modular organization. In addition, pVT1 presents a copy number of 9, relatively high for a conjugative plasmid, and appears to belong to a new type of replicon, which may be specific to Vibrionaceae and Shewanelleacae

Extraction of solar coronal magnetic loops with the directional 2D Morlet wavelet transform

We present an automated extraction method based on the continuous wavelet transform (CWT) for analyzing solar magnetic loops. The aim of the work is to extract, from the images taken from solar EUV telescopes, the traces of bright loops presumably shaped by the magnetic field of the solar corona. The technique is that of wavelet analysis, using the two-dimensional Morlet wavelet, because of its efficiency in detecting oriented features, which allows us to follow closely the curvature of the loops. Next, we segment the wavelet modulus image and we threshold it, both globally and locally (i.e., adaptively), in order to eliminate the remaining noise. Altogether, our method performs well, it is robust and fast, and could be used as a standard tool for analyzing large data sets expected from missions like SDO

Mitigating high-temperature vulnerabilities in concrete: utilizing waste plastic fibers for enhanced mechanical resilience and environmental sustainability

The susceptibility of concrete to elevated temperatures is a paramount concern in civil engineering, especially in fire-related scenarios. This material often suffers mechanical weaknesses such as fracturing and reduced durability under high temperatures. Despite its ubiquitous use, concrete’s vulnerability to thermal stress presents significant challenges for maintaining structural integrity and safety. The novelty of this work lies in its innovative approach to addressing these challenges by proposing the utilization of waste plastic fibers, which are readily available due to the extensive use of various plastic products. This approach not only enhances the mechanical resilience of concrete but also contributes to mitigating environmental and health impacts associated with plastic waste. The research focuses on the effects of high temperatures on the mechanical properties of sand concrete reinforced with fibrous materials. Concrete specimens were prepared with different lengths (1 cm and 2 cm) of packing tape fibers at concentrations of 1% and 2%. These specimens underwent controlled thermal treatments ranging from 100 °C to 700 °C with a heating rate of 1 °C/min, following a 90-day water immersion curing period. The evaluation encompassed various tests including visual inspection, residual weight measurement, residual compressive and tensile strength assessments, and ultrasonic pulse velocity (UPV) testing. The analysis revealed a notable improvement in mechanical strength for concrete reinforced with 1% fibers at 300 °C. However, exposure to higher temperatures (500 °C and 700 °C) led to a significant decline in strength across all samples due to the evaporation of fibers, resulting in the formation of voids and conduits within the concrete’s structure. While previous research has extensively investigated the effectiveness of polypropylene fibers in crack mitigation during fire incidents, limited attention has been given to the potential of plastic waste as a reinforcement material. Thus, this study’s novelty contributes to expanding the scientific understanding of using waste plastic fibers to enhance concrete’s resilience to high temperatures, thereby filling a crucial gap in existing literature