7,581 research outputs found

    Non-collaborative Attackers and How and Where to Defend Flawed Security Protocols (Extended Version)

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    Security protocols are often found to be flawed after their deployment. We present an approach that aims at the neutralization or mitigation of the attacks to flawed protocols: it avoids the complete dismissal of the interested protocol and allows honest agents to continue to use it until a corrected version is released. Our approach is based on the knowledge of the network topology, which we model as a graph, and on the consequent possibility of creating an interference to an ongoing attack of a Dolev-Yao attacker, by means of non-collaboration actuated by ad-hoc benign attackers that play the role of network guardians. Such guardians, positioned in strategical points of the network, have the task of monitoring the messages in transit and discovering at runtime, through particular types of inference, whether an attack is ongoing, interrupting the run of the protocol in the positive case. We study not only how but also where we can attempt to defend flawed security protocols: we investigate the different network topologies that make security protocol defense feasible and illustrate our approach by means of concrete examples.Comment: 29 page

    Proof Theory, Transformations, and Logic Programming for Debugging Security Protocols

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    We define a sequent calculus to formally specify, simulate, debug and verify security protocols. In our sequents we distinguish between the current knowledge of principals and the current global state of the session. Hereby, we can describe the operational semantics of principals and of an intruder in a simple and modular way. Furthermore, using proof theoretic tools like the analysis of permutability of rules, we are able to find efficient proof strategies that we prove complete for special classes of security protocols including Needham-Schroeder. Based on the results of this preliminary analysis, we have implemented a Prolog meta-interpreter which allows for rapid prototyping and for checking safety properties of security protocols, and we have applied it for finding error traces and proving correctness of practical examples

    GAMBARAN KECUKUPAN MINERAL MAKRO PADA MAHASISWA SEMESTER IV FAKULTAS KESEHATAN MASYARAKAT UNIVERSITAS SAM RATULANGI MANADO SELAMA MASA PANDEMI COVID-19

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    Mineral makro merupakan mineral yang paling dibutuhkan tubuh paling banyak lebih dari 100 mg/hari. Kebutuhan mineral pada masa usia remaja saat ini meningkat. Dalam masa pandemi ini salah satu pencegahan dalam melawan virus corona atau COVID-19 yaitu menjaga sistem imunitas diri  dengan mengkonsumsi gizi seimbang. Tercukupinya asupan mineral makro selama masa pandemi COVID-19 ini, maka kebutuhan gizi tubuh tetap terpenuhi dan bisa mempertahankan daya tahan tubuh hingga bisa mencegah dari virus ini. Tujuan dari penelitian ini adalah untuk mengetahui gambaran kecukupan mineral makro pada mahasiswa semester IV Fakultas Kesehatan Masyarakat Universitas Sam Ratulangi Selama Masa Pandemi COVID-19 Tahun 2020. Penelitian ini bersifat deskriptif, yang dilaksanakan pada bulan Juli – November 2020, di Fakultas Kesehatan Masyarakat Universitas Sam Ratulangi Manado dengan jumlah sampel  91 responden. Instrumen penelitian yang digunakan yaitu formulir  identitas responden dan formulir  food record yang berisi data asupan responden selama 2 hari. Hasil ini menunjukkan asupan natrium kurang 81 (89,0%), kategori baik 9 (9,9%)  kategori lebih 1 (1,1%), asupan kalium semuanya termasuk kategori kurang yaitu 91 (100%), asupan fosfor kurang yaitu 38 (41,8%), kategori baik  18 (19,8%) kategori lebih berjumlah 35 orang (38,4%), asupan kalsium kurang yaitu 75 (82,4%), untuk kategori lebih 15 orang (15,4%), kalsium kategori baik bejumlah 2 orang (2,2%), magnesium kategori kurang 76 orang (83,5,4%), yang kategori baik 10 orang (11,0%) kategori lebih 5 orang (5,5%). Kata Kunci: Kecukupan Mineral Makro, Mahasiswa, COVID-19 ABSTRACTMacro minerals are the minerals most needed by the body at most more than 100 mg / day. The need for minerals in adolescence is currently increasing. During this pandemic, one of the preventions against the corona virus or COVID-19 is to maintain the immune system by consuming balanced nutrition. With adequate intake of macro minerals during the COVID-19 pandemic, the body's nutritional needs are still met and can maintain the body's immune system so that it can prevent this virus. The purpose of this study was to determine the adequacy of macro minerals in semester IV students of the Faculty of Public Health, Sam Ratulangi University during the COVID-19 Pandemic in 2020. This research is descriptive in nature, which was conducted in July - November 2020, at the Faculty of Public Health, Sam University. Ratulangi Manado with a sample size of 91 respondents. The research instruments used were the respondent's identity form and the food record form containing the respondent's intake data for 2 days. These results indicated that sodium intake was less than 81 (89.0%), good category 9 (9.9%) over category 1 (1.1%), all potassium intake was in the poor category, namely 91 (100%), less phosphorus intake, namely 38 (41.8%), good category 18 (19.8%) more categories totaled 35 people (38.4%), less calcium intake was 75 (82.4%), for more category 15 people (15.4 %), 2 people in good category calcium (2.2%), 76 people in poor category (83.5.4%), 10 people in good category (11.0%) 5 more categories (5.5%) Keywords: Adequacy of Macro Minerals, Students, COVID-1

    Towards elimination of measles and rubella in Italy. Progress and challenges

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    Introduction In the WHO European Region, endemic transmission of measles and rubella had been interrupted by 37 and 42 of the 53 member states (MSs), respectively, by 2018. Sixteen MSs are still endemic for measles, 11 for rubella and nine for both diseases, the latter including Italy. Elimination is documented by each country’s National Verification Committee (NVC) through an annual status update (ASU). Objective By analysing data used to produce the ASUs, we aimed to describe the advances made by Italy towards elimination of measles and rubella. Moreover, we propose a set of major interventions that could facilitate the elimination process. Methods A total of 28 indicators were identified within the six core sections of the ASU form and these were evaluated for the period 2013–2018. These indicators relate to the incidence of measles/rubella; epidemiological investigation of cases; investigation of outbreaks; performance of the surveillance system; population immunity levels; and implementation of supplemental immunization activities (SIAs). Results From 2013 to 2018, epidemiological and laboratory analyses of measles cases in Italy improved substantially, allowing timely investigation in 2017 and 2018 of most outbreak and sporadic cases and identification of the majority of genotypic variants. Moreover, since 2017, vaccination coverage has increased significantly. Despite these improvements, several areas of concern emerged, prompting the following recommendations: i) improve outbreak monitoring; ii) strengthen the MoRoNet network; iii) increase the number of SIAs; iv) reinforce vaccination services; v) maintain regional monitoring; vi) design effective communication strategies; vii) foster the role of general practitioners and family paediatricians. Conclusions The review of national ASUs is a crucial step to provide the NVC with useful insights into the elimination process and to guide the development of targeted interventions. Against this background, the seven recommendations proposed by the NVC have been shared with the Italian Ministry of Health and the Technical Advisory Group on measles and rubella elimination and have been incorporated into the new Italian Elimination Plan 2019–2023 as a technical aid to facilitate the achievement of disease elimination goals

    Nanosponge-based composite gel polymer electrolyte for safer li-o2 batteries

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    Li-O2 batteries represent a promising rechargeable battery candidate to answer the energy challenges our world is facing, thanks to their ultrahigh theoretical energy density. However, the poor cycling stability of the Li-O2 system and, overall, important safety issues due to the formation of Li dendrites, combined with the use of organic liquid electrolytes and O2 cross-over, inhibit their practical applications. As a solution to these various issues, we propose a composite gel polymer electrolyte consisting of a highly cross-linked polymer matrix, containing a dextrin-based nanosponge and activated with a liquid electrolyte. The polymer matrix, easily obtained by thermally activated one pot free radical polymerization in bulk, allows to limit dendrite nucleation and growth thanks to its cross-linked structure. At the same time, the nanosponge limits the O2 cross-over and avoids the formation of crystalline domains in the polymer matrix, which, combined with the liquid electrolyte, allows a good ionic conductivity at room temperature. Such a composite gel polymer electrolyte, tested in a cell containing Li metal as anode and a simple commercial gas diffusion layer, without any catalyst, as cathode demonstrates a full capacity of 5.05 mAh cm−2 as well as improved reversibility upon cycling, compared to a cell containing liquid electrolyte

    An Overview on Anodes for Magnesium Batteries: Challenges towards a Promising Storage Solution for Renewables

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    Magnesium-based batteries represent one of the successfully emerging electrochemical energy storage chemistries, mainly due to the high theoretical volumetric capacity of metallic magnesium (i.e., 3833 mAh cm−3 vs. 2046 mAh cm−3 for lithium), its low reduction potential (−2.37 V vs. SHE), abundance in the Earth’s crust (104 times higher than that of lithium) and dendrite-free behaviour when used as an anode during cycling. However, Mg deposition and dissolution processes in polar organic electrolytes lead to the formation of a passivation film bearing an insulating effect towards Mg2+ ions. Several strategies to overcome this drawback have been recently proposed, keeping as a main goal that of reducing the formation of such passivation layers and improving the magnesium-related kinetics. This manuscript offers a literature analysis on this topic, starting with a rapid overview on magnesium batteries as a feasible strategy for storing electricity coming from renewables, and then addressing the most relevant outcomes in the field of anodic materials (i.e., metallic magnesium, bismuth-, titanium- and tin-based electrodes, biphasic alloys, nanostructured metal oxides, boron clusters, graphene-based electrodes, etc.)

    An exploratory study of MoS2 as anode material for potassium batteries

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    Potassium-based batteries represent one of the emerging classes of post-lithium electrochemical energy storage systems in the international scene, due to both the abundance of raw materials and achievable cell potentials not far from those of lithium batteries. In this context, it is important to define electrodes and electrolytes that give reproducible performance and that can be used by different research groups as an internal standard when developing new materials. We propose molybdenum disulfide (MoS2) as a valid anode choice, being a commercial and easily processable material, the 2D layered structure of which is promising for large potassium ions reversible storage. It has been proven to work for hundreds of cycles, keeping a constant specific capacity around 100 mAh g−1 while also preserving its electrochemical interphase and morphology

    Costimulatory Molecules and Immune Checkpoints Are Differentially Expressed on Different Subsets of Dendritic Cells

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    Dendritic cells (DCs) play a crucial role in initiating and shaping immune responses. The effects of DCs on adaptive immune responses depend partly on functional specialization of distinct DC subsets, and partly on the activation state of DCs, which is largely dictated by environmental signals. Fully activated immunostimulatory DCs express high levels of costimulatory molecules, produce pro-inflammatory cytokines, and stimulate T cell proliferation, whereas tolerogenic DCs express low levels of costimulatory molecules, produce immunomodulatory cytokines and impair T cell proliferation. Relevant to the increasing use of immune checkpoint blockade in cancer treatment, signals generated from inhibitory checkpoint molecules on DC surface may also contribute to the inhibitory properties of tolerogenic DCs. Yet, our knowledge on the expression of inhibitory molecules on human DC subsets is fragmentary. Therefore, in this study, we investigated the expression of three immune checkpoints on peripheral blood DC subsets, in basal conditions and upon exposure to pro-inflammatory and anti-inflammatory stimuli, by using a flow cytometric panel that allows a direct comparison of the activatory/inhibitory phenotype of DC-lineage and inflammatory DC subsets. We demonstrated that functionally distinct DC subsets are characterized by differential expression of activatory and inhibitory molecules, and that cDC1s in particular are endowed with a unique immune checkpoint repertoire characterized by high TIM-3 expression, scarce PD-L1 expression and lack of ILT2. Notably, this unique cDC1 repertoire was subverted in a group of patients with myelodysplastic syndromes included in the study. Applied to the characterization of DCs in the tumor microenvironment, this panel has the potential to provide valuable information to be used for investigating the role of DC subsets in cancer, guiding DC-targeting treatments, and possibly identifying predictive biomarkers for clinical response to cancer immunotherapy

    Assessment of the levels of degradation in fat co- and by-products for feed uses and their relationships with some lipid composition parameters

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    This paper discusses the levels of degradation of some co- and byproducts of the food chain intended for feed uses. As the first part of a research project, 'Feeding Fats Safety', financed by the sixth Framework Programme-EC, a total of 123 samples were collected from 10 European countries, corresponding to fat co- and byproducts such as animal fats, fish oils, acid oils from refining, recycled cooking oils, and other. Several composition and degradation parameters (moisture, acid value, diacylglycerols and monoacylglycerols, peroxides, secondary oxidation products, polymers of triacylglycerols, fatty acid composition, tocopherols, and tocotrienols) were evaluated. These findings led to the conclusion that some fat by- and coproducts, such as fish oils, lecithins, and acid oils, show poor, nonstandardized quality and that production processes need to be greatly improved. Conclusions are also put forward about the applicability and utility of each analytical parameter for characterization and quality control
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