Semi-regular continued fractions and an exact formula for the moments of the Minkowski question mark function

This paper continues investigations on the integral transforms of the Minkowski question mark function. In this work we finally establish the long-sought formula for the moments, which does not explicitly involve regular continued fractions, though it has a hidden nice interpretation in terms of semi-regular continued fractions. The proof is self-contained and does not rely on previous results by the author.Comment: 8 page

Anthropogenic fibers and microplastics in the pelagic gooseneck barnacle Lepas (Lepas) anatifera in Capo Milazzo Marine Protected Area (Tyrrhenian Sea): A first characterization

This study provides an assessment of the efficiency of the biofouler Lepas (Lepas) anatifera Linnaeus, 1758 in capturing microplastics and microfiber particles floating in the water column. In this context, we collected pelagic gooseneck barnacles at fixed moorings in the Capo Milazzo Marine Protected Area (MPA). Fibers and fragments were found in the digestive tract of 30% of the 120 specimens collected. The ingested debris were mainly fibers (85.9%) of synthetic (30.6%) and natural (11.7%) origin, with length ranging between 1 and 2 mm (33.3%) and transparent (47.2%). The highest concentration of fibers was recorded in barnacles collected in the western sector of the MPA that is more affected by the input of organic matter coming from several urban wastewaters. No correlation was found between the presence of artificial polymers in L. (Lepas) anatifera and the size of individuals. The great diversity of fibers and plastic fragments by typology, size, shape and color, as well as the large number of bivalve and ostracod shells found in the digestive tract of the samples, confirm the opportunistic diet of these organisms, which can indiscriminately ingest any type of prey and cannot distinguish between microplastics and food. The results obtained, as well as the wide distribution and abundance, and ease of sampling of these barnacle species in macrofouling suggest that including this species in monitoring programs could be a cost-effective and easy method for assessing the presence of microplastics and microfibers in coastal marine waters to monitor the ecological status of pelagic and coastal ecosystems, including MPAs

Electron-hole asymmetry in two-terminal graphene devices

A theoretical model is proposed to describe asymmetric gate-voltage dependence of conductance and noise in two-terminal ballistic graphene devices. The model is analyzed independently within the self-consistent Hartree and Thomas-Fermi approximations. Our results justify the prominent role of metal contacts in recent experiments with suspended graphene flakes. The contact-induced electrostatic potentials in graphene demonstrate a power-law decay with the exponent varying from -1 to -0.5. Within our model we explain electron-hole asymmetry and strong Fabri-Perot oscillations of the conductance and noise at positive doping, which were observed in many experiments with submicrometer samples. Limitations of the Thomas-Fermi approximation in a vicinity of the Dirac point are discussed.Comment: 7 pages, 8 figure

Gradients of Variation in the At-Vessel Mortality Rate between Twelve Species of Sharks and Skates Sampled through a Fishery-Independent Trawl Survey in the Asinara Gulf (NW Mediterranean Sea)

Elasmobranchs are priority species for conservation due to their rapid decline determined by the unbalanced struggle between a fragile bio-ecology and strong anthropogenic impacts, such as bycatch from professional fishing. In this context, measuring species resistance to catch of poorly selective gear is of paramount importance. During June-October 2022, five experimental fishing campaigns were carried out in the Asinara Gulf (northern Sardinia) through 35 geographically and bathymetrically representative hauls of an area between 30 and 600 m in depth. Skates prevailed over sharks in the number of species, with seven and five species, respectively. We first evaluated the status of each individual with respect to stress due to the trawl's catch using a three-graded scale. We also recorded individual biometrics (total and disk length, weight and sex, and maturity for males) on board by implementing the best practices in manipulating individuals for physiological recovery and release at sea. After capture, skates resulted in generally better conditions than sharks, although deepwater species of both groups exhibited a worse state than coastal species. The estimated vitality rates also depended on the size of the individuals. This work provides standardized data on the intermingled effect of size, species type, and inhabited depth on the resistance response of some elasmobranch species against capture by trawl fishery activities

Caesarean section at Usmanu Danfodiyo University Teaching Hospital: a cross sectional study

Introduction: Caesarean section remains the most common major operation performed on women worldwide and the rate is increasing.The World Health Organization (WHO) consider caesarean section rate of 5-15% to be optimum.Objective: To determine the rate of caesarean section, major indications, pregnancy out-come and the complications.Subjects and Methods:This is a prospective study of all the cases of caesarean sections performed between 1st of January,2012 and 31th of December,2013 at UDUTH,Sokoto-Nigeria.The data were collated and analyzed using statistical soft package ware for social sciences (SPSS) version 20.Results: A total of 4,115 deliveries were recorded during the study period and 435 of them (10.6%) were through caesarean section (CS). Emergency CS accounted for 65.1% of caesarean deliveries.The mean age was 28±6 years. Previous CS was the commonest indication for caesarean section (25.7%). Elective CS had better fetal outcome (t = 7.440,df =388.523,p < 0.001),while spinal anaesthesia was associated with less blood loss (t = 4.569, df=63.223 and p < 0.001) and better fetal outcome (t = 4.237, df = 57.224, p < 0.001).Anaemia (19.8%) was the commonest complications encountered in the post operative period.Conclusion: The CS rate from this study is within the WHO recommended rate. Previous CS was the commonest indication,the outcome was better among women that had elective CS under regional anaesthesia.Keywords: Caesarean section, CS rate, indication and outcom

“Test Tube Cetaceans”: From the Evaluation of Susceptibility to the Study of Genotoxic Effects of Different Environmental Contaminants Using Cetacean Fibroblast Cell Cultures

Population estimates of various species of cetaceans indicate that certain species have declined dramatically this century. Most studies of contamination and biomarker responses in marine mammals have been conducted using animals killed by hunting, tacitly approving this activity. The development of a series of nondestructive techniques to evaluate biomarker responses and residue levels is strongly recommended for the hazard assessment, protection and conservation of endangered species of marine mammals. A non-invasive sampling method, represented by skin biopsy or integument biopsy (epidermis, dermis and blubber), have been developed and validated in cetaceans. In this paper we present the cetacean fibroblast cell cultures obtained from the skin biopsies as the “test tube cetacean” for evaluate both the susceptibility that the genotoxicity of different environmental contaminants. Fibroblast cell cultures were obtained from many species of cetaceans sampled in Mediterranean Sea (Italy) and in the Mar de Cortez (Mexico). Using test tube cetaceans we can study the relationships between contamination and biochemical responses. One of the principal applications of this developed in vitro system was the assessment of interspecies differences in the mixed function oxidase activity (Cyp1A1 and Cyp2B) induced by in vitro treatment of various contaminants, such as some Persistent Organic Pollutants (POPs) but also emerging contaminants (such as bisphenol A (BpA)) and nanoparticles, added at different concentrations. The induction of Cyp1A1 and Cyp2B was evaluated with the indirect immunofluorescence technique. Therefore, another purpose of this work was to evaluate the qualitative and quantitative MICA protein expression in fibroblast cell cultures with immunofluorescence technique as toxicological stress marker of the immune system of different species of cetaceans. Finally, In this paper we will present how to evaluate the presence of DNA damage by comet assay in test tube cetaceans, after treatment with different genotoxic compounds (for example PCBs, DDTs, PAHs, BPA)

Recognising facial expressions in video sequences

We introduce a system that processes a sequence of images of a front-facing human face and recognises a set of facial expressions. We use an efficient appearance-based face tracker to locate the face in the image sequence and estimate the deformation of its non-rigid components. The tracker works in real-time. It is robust to strong illumination changes and factors out changes in appearance caused by illumination from changes due to face deformation. We adopt a model-based approach for facial expression recognition. In our model, an image of a face is represented by a point in a deformation space. The variability of the classes of images associated to facial expressions are represented by a set of samples which model a low-dimensional manifold in the space of deformations. We introduce a probabilistic procedure based on a nearest-neighbour approach to combine the information provided by the incoming image sequence with the prior information stored in the expression manifold in order to compute a posterior probability associated to a facial expression. In the experiments conducted we show that this system is able to work in an unconstrained environment with strong changes in illumination and face location. It achieves an 89\% recognition rate in a set of 333 sequences from the Cohn-Kanade data base