Building Regular Registers with Rational Malicious Servers and Anonymous Clients

The paper addresses the problem of emulating a regular register in a synchronous distributed system where clients invoking $$\mathsf{read}()$$ and $$\mathsf{write}()$$ operations are anonymous while server processes maintaining the state of the register may be compromised by rational adversaries (i.e., a server might behave as rational malicious Byzantine process). We first model our problem as a Bayesian game between a client and a rational malicious server where the equilibrium depends on the decisions of the malicious server (behave correctly and not be detected by clients vs returning a wrong register value to clients with the risk of being detected and then excluded by the computation). We prove such equilibrium exists and finally we design a protocol implementing the regular register that forces the rational malicious server to behave correctly

Cônicas com dobraduras e GeoGebra: uma possível abordagem para a educação básica

Apresenta-se a análise de resultados obtidos com duas construções da cônica parábola, com um grupo de estudantes de Licenciatura em Matemática, uma com dobraduras no papel e lápis e outra com o aplicativo GeoGebra para celular. O objetivo foi avaliar se esses futuros professores de Matemática estabelecem conjecturas diante do visto e percebem que é necessário justificar que a curva vislumbrada, no papel e no celular, existe e é uma parábola. Os Três Mundos da Matemática constituiu o campo teórico que embasou a análise dos dados. Esta revelou possibilidades reais para o ensino com as abordagens propostas, como forma de estimular o estabelecimento de conjecturas e justificativas em Matemática

Implementing a Register in a Dynamic Distributed System

Providing distributed processes with concurrent objects is a fundamental service that has to be offered by any distributed system. The classical shared read/write register is one of the most basic ones. Several protocols have been proposed that build an atomic register on top of an asynchronous messagepassing system prone to process crashes. In the same spirit, this paper addresses the implementation of a regular register (a weakened form of an atomic register) in an asynchronous dynamic message-passing system. The aim is here to cope with the net effect of the adversaries that are asynchrony and dynamicity (the fact that processes can enter and leave the system). The paper focuses on the class of dynamic systems the churn rate c of which is constant. It presents two protocols, one applicable to synchronous dynamic message passing systems, the other one to asynchronous dynamic systems. Both protocols rely on an appropriate broadcast communication service (similar to a reliable brodcast). Each requires a specific constraint on the churn rate c. Both protocols are first presented in an as intuitive as possible way, and are then proved correct

Brazilian Beach-Cast Seaweeds: Antioxidant, Photoprotection and Cytotoxicity Properties.

The potential of seaweed extracts in cosmetic applications have increased with novel development and market. Beneficial biological properties include the ability to struggle aging and anticancer agents. This research aimed to evaluate antioxidant, photoprotective and cytotoxic properties of extracts from beach-cast seaweed species from the Brazilian coast in order to propose an appropriate use of this sustainable resource. Analysis of antioxidant capacity, UV/VIS absorption, quantification of UV photoprotectors, total content of C, N and S, development of cosmetic creams and evaluation of the cytotoxicity activity against tumoral cells lines were performed. The highest antioxidant capacity was found in extracts of brown seaweeds, followed by red seaweeds, with the lowest activity detected in the green seaweed. Same pattern was observed for phenolic compounds. The extracts did not show cytotoxicity activity against healthy human cells. Other forms of extraction and incorporation of the extract into the base creams should be evaluated, the isolation and purification of substances could increase the efficiency of the photoprotective capacity. The species were highly promising and proved to be natural sources of antioxidants and substances with cytotoxicity activity against tumoral cells; therefore, they could be exploited as functional ingredients with specific applications for different types of industries. The application of seaweed extracts in combination with other natural ingredients can help in the design of new cosmetics against the negative effects of UV radiation, in addition to having the great advantage of not presenting toxicity to health or the environment because they are biodegradable.Funding for open access publishing: Universidad Málaga/CBUA. // TBH thanks to CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico; 140144/2017-0) for financial support and PhD scholarship and CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior; Code 001) for funding the postgraduate program in Botany at the Institute of Bioscience and PhD sandwich scholarship (88887.368014/2019-00). FC thanks FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo; 2018/18015-8) for financial support and CNPq for research productivity grants (303937/2015-7; 303493/2018-6). This work is part of the international research project BMBF 031B0284 (023/IVV-113816). FLF thanks the financial support by the Ministry of Sciences and Innovation (BlueMaro Project, PID2020-116136RB-I0) and by the Government of Andalusia (Facco Project - UMA18-FEDER JA-162 and NAZCA Project -P20-004589)

Promotion of manual drilling in Guinea

In the last decade UNICEF has supported manual drilling in several countries as a possible low cost and sustainable strategy to increase adequate water supply for the population. In partnership with local authorities and other stakeholders, UNICEF has implemented different activities to ensure high professional level in manual drilling: mapping of suitable zones, capacity building in construction of drilling tools and application of different drilling techniques, good practice in manual drilling, organization management. In Guinea manual drilling was unknown before 2011; at that time the joint program of SNAPE (National Water Authority) and UNICEF aiming to create an efficient manual drilling sector started, and after 3 years Guinea can be considered one of the most positive example of implementation of this program

Improvement of neutrophil gelatinase-associated lipocalin sensitivity and specificity by two plasma measurements in predicting acute kidney injury after cardiac surgery

Introduction: Acute kidney injury (AKI) remains among the most severe complication after cardiac surgery. The aim of this study was to evaluate the neutrophil gelatinase-associated lipocalin (NGAL) as possible biomarker for the prediction of AKI in an adult cardiac population. Materials and methods: Sixty-nine consecutive patients who underwent cardiac surgeries in our hospital were prospectively evaluated. In the intensive care unit (ICU) NGAL was measured as a new biomarker of AKI besides serum creatinine (sCrea). Patients with at least two factors of AKI risk were selected and samples collected before the intervention and soon after the patient’s arrival in ICU. As reference standard, sCrea measurements and urine outputs were evaluated to define the clinical AKI. A Triage Meter for plasma NGAL fluorescence immunoassay was used. Results: Acute kidney injury occurred in 24 of the 69 patients (35%). Analysis of post-operative NGAL values demonstrated an AUC of 0.71, 95% CI (0.60 - 0.82) with a cut-off = 154 ng/mL (sensitivity = 76%, specificity = 59%). Moreover, NGAL after surgery had a good correlation with the AKI stage severity (P ≤ 0.001). Better diagnostic results were obtained with two consecutive tests: sensitivity 86% with a negative predictive value (NPV) of 87%. At 10-18 h after surgery sCrea measurement, as confirmatory test, allowed to reach a more sensitivity and specificity with a NPV of 96%. Conclusions: The assay results showed an improvement of NGAL diagnostic accuracy evaluating two tests. Consequently, NGAL may be useful for a timely treatment or for the AKI rule out in ICU patients

Anlisis Technology Acceptance Model Pada Industri Perbankan

The first aim of this study was to determine the influence perception of the perceived benefits (PU) and perceived ease of use (PEU) of the attitude (ATU) in receiving information technology (ATI). This research is an explanatory research. Respondents are bank employees as much as 118 peoples. To test the effect of each variable used structural equation modeling analysis techniques (SEM). The results showed a variable perception ease of use (PEU) positive and significant impact on the attitude of using IT (ATU). Variable perception perceived benefits (PU) is positive but not significant effect on attitudes using IT (ATU). Variable perception easy to use (PEU) positive and significant impact on the perceived benefits perception variables (PU). Variable attitude of using IT (ATU) positive and significant impact on the acceptance of IT (ATI). There are research findings that do not support the results of previous studies, namely, perception perceived benefits (PU) but not significant positive effect on the attitude of using IT (ATU). This shows the attitude of the management agreed that the use of information technology is an important banking and its presence is felt very beneficial to the organization and operational staff, but not the key element in determining the attitude to use IT. The management should be able to realize the quality of skilled workers and professional service. The banking industry can standardize that can be used as a reference for the development of IT. IT use also should be able to grow the level of trust and a culture conducive to the customer as a party that directly or indirectly affect the use of IT

Identification of suitable zones for manual drilling using borehole data, thematic maps and remote sensing

Manual drilling is a possible option to increase access to safe water with low cost techniques, but it can be applied only where hydrogeological conditions are suitable. To improve the method to produce maps of suitable zones for manual drilling, a research project has been carried out in Senegal and Guinea. The main objective is to elaborate a new method of interpretation of hydrogeological data and integrate indirect environmental information obtained from public data, available all over the world. The final results are more reliable and detailed maps to support manual drilling implementation, as well specific tools and method to process water point data. This paper presents the results obtained in Senegal and suggests some recommendations for future application

Human mesenchymal stromal cells inhibit tumor growth in orthotopic glioblastoma xenografts

Background: Mesenchymal stem/stromal cells (MSCs) represent an attractive tool for cell-based cancer therapy mainly because of their ability to migrate to tumors and to release bioactive molecules. However, the impact of MSCs on tumor growth has not been fully established. We previously demonstrated that murine MSCs show a strong tropism towards glioblastoma (GBM) brain xenografts and that these cells are able to uptake and release the chemotherapeutic drug paclitaxel (PTX), maintaining their tropism towards the tumor. Here, we address the therapy-relevant issue of using MSCs from human donors (hMSCs) for local or systemic administration in orthotopic GBM models, including xenografts of patient-derived glioma stem cells (GSCs). Methods: U87MG or GSC1 cells expressing the green fluorescent protein (GFP) were grafted onto the striatum of immunosuppressed rats. Adipose hMSCs (Ad-hMSCs), fluorescently labeled with the mCherry protein, were inoculated adjacent to or into the tumor. In rats bearing U87MG xenografts, systemic injections of Ad-hMSCs or bone marrow (BM)-hMSCs were done via the femoral vein or carotid artery. In each experiment, either PTX-loaded or unloaded hMSCs were used. To characterize the effects of hMSCs on tumor growth, we analyzed survival, tumor volume, tumor cell proliferation, and microvascular density. Results: Overall, the AD-hMSCs showed remarkable tropism towards the tumor. Intracerebral injection of Ad-hMSCs significantly improved the survival of rats with U87MG xenografts. This effect was associated with a reduction in tumor growth, tumor cell proliferation, and microvascular density. In GSC1 xenografts, intratumoral injection of Ad-hMSCs depleted the tumor cell population and induced migration of resident microglial cells. Overall, PTX loading did not significantly enhance the antitumor potential of hMSCs. Systemically injected Ad- and BM-hMSCs homed to tumor xenografts. The efficiency of hMSC homing ranged between 0.02 and 0.5% of the injected cells, depending both on the route of cell injection and on the source from which the hMSCs were derived. Importantly, systemically injected PTX-loaded hMSCs that homed to the xenograft induced cytotoxic damage to the surrounding tumor cells. Conclusions: hMSCs have a therapeutic potential in GBM brain xenografts which is also expressed against the GSC population. In this context, PTX loading of hMSCs seems to play a minor role