838 research outputs found
Detection and identification of sparse audio tampering using distributed source coding and compressive sensing techniques
In most practical applications, for the sake of information integrity not only it is useful to detect whether a multimedia content has been modified or not, but also to identify which kind of attack has been carried
out. In the case of audio streams, for example, it may be useful to localize the tamper in the time and/or frequency domain. In this paper we devise a hash-based tampering detection and localization system
exploiting compressive sensing principles. The multimedia content provider produces a small hash signature using a limited number of random projections of a time-frequency representation of the original
audio stream. At the content user side, the hash signature is used to estimate the distortion between the original and the received stream and, provided that the tamper is sufficiently sparse or sparsifiable in
some orthonormal basis expansion or redundant dictionary (e.g. DCT or wavelet), to identify the time-frequency portion of the stream that has been manipulated. In order to keep the hash length small, the
algorithm exploits distributed source coding techniques
Identification of Sparse Audio Tampering Using Distributed Source Coding and Compressive Sensing Techniques
In the past few years, a large amount of techniques have been proposed to identify whether a multimedia content has been illegally tampered or not. Nevertheless, very few efforts have been devoted to identifying which kind of attack has been carried out, especially due to the large data required for this task. We propose a novel hashing scheme which exploits the paradigms of compressive sensing and distributed source coding to generate a compact hash signature, and we apply it to the case of audio content protection. The audio content provider produces a small hash signature by computing a limited number of random projections of a perceptual, time-frequency representation of the original audio stream; the audio hash is given by the syndrome bits of an LDPC code applied to the projections. At the content user side, the hash is decoded using distributed source coding tools. If the tampering is sparsifiable or compressible in some orthonormal basis or redundant dictionary, it is possible to identify the time-frequency position of the attack, with a hash size as small as 200 bits/second; the bit saving obtained by introducing distributed source coding ranges between 20% to 70%
Designing human-centric software artifacts with future users: a case study
The quality and quantity of participation supplied by human beings during the different phases of the design and development of a software artifact are central to studies in human-centered computing. With this paper, we have investigated on what kind of experienced people should be engaged to design a new computational artifact, when a participatory approach is adopted. We compared two approaches: the former including only future users (i.e., novices) in the design process, and the latter enlarging the community to expert users. We experimented with the design of a large software artifact, in use at the University of Bologna, engaging almost 1500 users. Statistical methodologies were employed to validate our findings. Our analysis has provided mounting evidence that expert users have contributed to the design of the artifact only by a small amount. Instead, most of the innovative initiatives have come from future users, thus surpassing some traditional limitations that tend to exclude future users from this kind of processes. We here challenge the traditional opinion that expert users provide typically a more reliable contribution in a participatory software design process, demonstrating instead that future users would be often better suited. Along this line of sense, this is the first paper, in the field of human-centric computing, that discusses the relevant question to offer to future users a larger design space, intended as a higher level of freedom given in a software design situation, demarcated by precise design constraints. In this sense, the outcome has been positiv
Comparison of AlphaLISA and RIA assays for measurement of wool cortisol concentrations
Radioimmunoassay (RIA) methods have always represented a technique of choice for the determination of steroids in biological samples. The Amplified Luminescent Proximity Homogenous Assay-Linked Immunosorbent Assay (AlphaLISA) is now emerging as the new-generation immunoassay technology that does not require washing/separation steps. The aim of this study was to adapt the Perkin-Elmer's AlphaLISA kit for wool cortisol and compare it with a RIA wool cortisol assay. Wool from lambs, 35 at birth (A0) and 54 at two months old (A2), was collected and each extract was evaluated for wool cortisol concentrations (HCC) both by RIA and AlphaLISA immunoassay. The two methods showed good precision, sensitivity and specificity for determining HCC. Both methods were able to detect significant differences between the high and the low HCC assessed in lambs at A0 and A2 (P < 0.01). The HCC assessed with RIA were significantly higher than those assessed with AlphaLISA (P < 0.01). Moreover, the correlation between HCC measured using the AlphaLISA and RIA methods was strong (r = 0.878). The regression analyses show a constant and not proportional error. This could be due to the diversity in the dosage steps and to the diversity of the molecules used in the two methods. Results support the validity of using AlphaLISA as an alternative method to RIA for the quantification of cortisol in sheep wool and considering the performances showed it has a great potential to be further applied as an excellent tool to evaluate HCC in samples derived from animal species
Extreme flooding events in coastal lagoons: seawater parameters and rainfall over a six-year period in the Mar Menor (SE Spain)
Climate change is one of the main problems currently strongly conditioning ecosystems all over the world. Coastal lagoons are amongst the most vulnerable habitats, and they are undergoing extensive human impact due to their high production rates and the close proximity of urban and agricultural centers. The Mar Menor, the largest saltwater lagoon in Europe, is an example of a highly impacted ecosystem. In December 2016 and September 2019, climate change-induced DANA
(upper-level isolated atmospheric depression) flooding events took place there, temporarily altering the lagoon oceanographic properties. Data gathered throughout the lagoon (11 stations inside and 1 outside the lagoon) from 2016 to 2021 were analyzed in order to assess the variability of seawater parameters: salinity, density, chlorophyll-a, turbidity, and dissolved oxygen, due to DANA events.
Results showed a change in seawater parameters that were reestablished at different rates, 4 and 10 months in 2016 and 2019, respectively, following a description of the environmental conditions and effects that have been reported after extreme rainfall in the lagoon. The amount of rainfall correlated with changes in the analyzed seawater parameters, such as an increase in turbidity and chlorophyll-a values. Furthermore, turbidity correlated with chlorophyll-a and oxygen saturation,
while density correlated with salinity. Such extreme weather events are worsened by climate change, growing more frequent and between shorter intervals in time. In order to decelerate ecosystem decline, comprehensive management plans are needed to address the various factors that might add to anthropic impacts in natural environments
Cortical-Inspired Wilson–Cowan-Type Equations for Orientation-Dependent Contrast Perception Modelling
We consider the evolution model proposed in BertalmĂo (Front Comput Neurosci 8:71, 2014), BertalmĂo et al. (IEEE Trans Image Process 16(4):1058–1072, 2007) to describe illusory contrast perception phenomena induced by surrounding orientations. Firstly, we highlight its analogies and differences with the widely used Wilson–Cowan equations (Wilson and Cowan in BioPhys J 12(1):1–24, 1972), mainly in terms of efficient representation properties. Then, in order to explicitly encode local directional information, we exploit the model of the primary visual cortex (V1) proposed in Citti and Sarti (J Math Imaging Vis 24(3):307–326, 2006) and largely used over the last years for several image processing problems (Duits and Franken in Q Appl Math 68(2):255–292, 2010; Prandi and Gauthier in A semidiscrete version of the Petitot model as a plausible model for anthropomorphic image reconstruction and pattern recognition. SpringerBriefs in Mathematics, Springer, Cham, 2017; Franceschiello et al. in J Math Imaging Vis 60(1):94–108, 2018). The resulting model is thus defined in the space of positions and orientation, and it is capable of describing assimilation and contrast visual bias at the same time. We report several numerical tests showing the ability of the model to reproduce, in particular, orientation-dependent phenomena such as grating induction and a modified version of the Poggendorff illusion. For this latter example, we empirically show the existence of a set of threshold parameters differentiating from inpainting to perception-type reconstructions and describing long-range connectivity between different hypercolumns in V1
Educazione terapeutica ai malati oncologici: esperienza degli infermieri italiani
Introduction. Therapeutic patient’ education is a complex process requiring a proper level of communication between the patient and the healthcare professional. Nurses play a key role in providing the patients and their families with educational activities. Objective: This paper is the report of a study which investigates the experiences of some Italian nurses with regards to their role in therapeutic education to cancer patients. Methods: Qualitative research. Semi-structured interviews were carried out with 52 nurses working in different Local Health Service Units of two northern Italy regions: Piedmont and Valle d’Aosta. To identify categories and items arising from the data, the researchers used a qualitative content analysis. Results: The interview format was classified into six main categories: a) Patient education as daily care activity; b) Relevance of communication and dialogue for educational purposes; c) Relative usefulness of written information; d) Therapeutic education recording; e) Patients’ feedbacks as a tool for assessing therapeutic education; and f) Difficult communication. Conclusions: The experience of nurses in terms of their professional role in therapeutic education for cancer patients shows the steady presence of educational activities carried out in a non-planned way. This research confirms the need to launch educational interventions for nurses. Implications for Practice: It is essential to implement an action plan to promote opportunities of professional training in the field since among the most frequent reasons for project failure in therapeutic education is the lack of expert human resource
Hair and Claw Dehydroepiandrosterone Concentrations in Newborn Puppies Spontaneously Dead within 30 Days of Age
The latest intrauterine fetal developmental stage and the neonatal period represent the most challenging phases for mammalian offspring. Toward the term of pregnancy, during parturition, and after birth, the hypothalamic–pituitary–adrenal axis (HPA) is a key system regulating several physiologic processes, through the production of cortisol and dehydroepiandrosterone (DHEA). This study was aimed to assess DHEA concentrations in hair and claws of 126 spontaneously dead newborn puppies, classified as premature puppies (PRE-P), stillborn puppies (STILL-P) and puppies that died from the 1st to the 30th day of life (NEON-P). The possible influence of newborn sex, breed body size, and timing of death on DHEA concentrations in both matrices was evaluated. Claw DHEA concentrations were higher in the PRE-P group when compared to STILL-P and NEON-P puppies (p < 0.05), whilst no significant differences were found in hair for all the studied factors. The results confirm the hypothesis that higher amounts of DHEA are produced during the intrauterine life in dogs, also in puppies that will die soon after birth
Ultrasound and Microwave-assisted Extraction of Proteins from Coffee Green Beans: Effects of Process Variables on the Protein Integrity
The demand for proteins is constantly increasing and green extraction methodologies are needed to achieve environmental sustainability goals. The recovery of the by-products of the agri-food chain has also become a priority from a circular economy perspective. Some by-products are still little exploited for the extraction of proteins, such as coffee by-products. In this work, various innovative extraction technologies were applied to recover the protein fraction from the non-compliant coffee green beans (CGB), using a methodological approach that allowed to correlate the process parameters with the final quality of the extracted proteins. The ultrasound-assisted extraction (UAE) technique has been shown to have a minor impact on the quality of the proteins, thanks to the possibility of refrigerating the system, while the microwave-assisted extraction (MAE) shows a certain degree of degradation due to the high temperatures reached. The results indicate that strict temperature control is required during alkaline extraction to preserve the quality of the protein fraction
Postnatal and postweaning endocrine setting in dairy calves through hair cortisol, dehydroepiandrosterone and dehydroepiandrosterone sulphate
Importance of the work: The care of calves on dairy farms between birth and weaning can improve their long-term development and growth. In fact, a poor newborn health status and a high allostatic load may adversely affect development in dairy cows. To determine cortisol, dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulphate (DHEA-S) individually is useful for an understanding of the individual state, being biomarkers of hypothalamic-pituitary-adrenal (HPA) axis activity. Objectives: As a preliminary study, to investigate the hair concentrations of cortisol, DHEA, DHEA-S and their ratios in dairy calves in two key periods of their growth characterized by considerable environmental changes. Materials & Methods: Hair sampling was conducted on clinically healthy dairy calves during the postnatal period at age 64.8±0.65 d (POP; mean±standard error; n = 73) and during the postweaning period at age 155.3±0.85 d (PWP, n = 62). The hair hormone concentrations were measured using a radioimmunoassay. Results: Hair cortisol concentrations were higher in the POP than in the PWP. Furthermore, the cortisol:DHEA and cortisol:DHEA-S ratios were higher in the first period of evaluation, showing a higher animal allostatic load at birth. Main finding: Identification was achieved non-invasively of calves with a high allostatic load through biomarkers of HPA axis activity. The evaluation of this activity is very important given its influence on many biological processes, such as energy balance, development of the reproductive system and immune response
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