Lightweight and adaptable solution for security agility

( Valter Vasic ),( Miljenko Mikuc ),( Marin Vukovic ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.3

Secure communication is an important aspect of today`s interconnected environments and it can be achieved by the use of cryptographic algorithms and protocols. However, many existing cryptographic mechanisms are tightly integrated into communication protocols. Issues emerge when security vulnerabilities are discovered in cryptographic mechanisms because their replacement would eventually require replacing deployed protocols. The concept of cryptographic agility is the solution to these issues because it allows dynamic switching of cryptographic algorithms and keys prior to and during the communication. Most of today`s secure protocols implement cryptographic agility (IPsec, SSL/TLS, SSH), but cryptographic agility mechanisms cannot be used in a standalone manner. In order to deal with the aforementioned limitations, we propose a lightweight cryptographically agile agreement model, which is formally verified. We also present a solution in the Agile Cryptographic Agreement Protocol (ACAP) that can be adapted on various network layers, architectures and devices. The proposed solution is able to provide existing and new communication protocols with secure communication prerequisites in a straightforward way without adding substantial communication overhead. Furthermore, it can be used between previously unknown parties in an opportunistic environment. The proposed model is formally verified, followed by a comprehensive discussion about security considerations. A prototype implementation of the proposed model is demonstrated and evaluated.

Comment on “Effect of Extracorporeal Shockwave Therapy Versus Intra-articular Injections of Hyaluronic Acid for the Treatment of Knee Osteoarthritis”

Valter Santilli,Federica Alviti,Marco Paoloni,Massimiliano Mangone,Andrea Bernetti 대한재활의학회 2018 Annals of Rehabilitation Medicine Vol.42 No.2

Extracts from Polypodium ferns upregulate the expression of CD95 in human peripheral blood lymphocytes

Lombardi, Valter R.M.,Etcheverria, I.,Fernandez-Novoa, L.,Blanco, A.,Diaz, J.,Cacabelos, R. Kyung Hee Oriental Medicine Research Center 2003 Oriental pharmacy and experimental medicine Vol.3 No.2

There are several data in the literature indicating a great variety of pharmacological activities of Polypodium genus, which exhibit antiinflammatory and immunomodulatory activities. Since one of our main interests is to obtain natural immunoregulatory agents devoid of pharmacological adverse effects, we used flow cytometry analysis to highlight relative contributions of a water-soluble fraction of different concentrations of Polypodium rhizome extracts on lymphocyte subpopulations, NK and LAK activity. To measure their potential immunoregulatory activity a T cell proliferation assay in response to phytohemaglutinin (PHA) and mixed lymphocyte reactions were chosen. As a confirmatory bioassay we studied the effect of our extracts on CD45RO and CD95 antigen expressions. The results indicate that CD95 expression dramatically increases after peripheral blood lymphocyte activation and treatment with Polypodium leucotomus, cambricum and vulgare extracts, suggesting a powerful intrinsic pro-apoptotic effect.

The FBH family of bHLH transcription factors controls ACC synthase expression in sugarcane

Alessio, Valter Miotto,Cavaç,ana, Natale,Dantas, Luí,za Lane de Barros,Lee, Nayoung,Hotta, Carlos Takeshi,Imaizumi, Takato,Menossi, Marcelo Oxford University Press 2018 Journal of experimental botany Vol.69 No.10

<▼1><P>Identification of transcription factors that control the expression of the sugarcane <I>ACS</I> gene, which is likely involved in ethylene-controlled sucrose accumulation and the circadian regulation of ethylene biosynthesis.</P></▼1><▼2><P><B>Abstract</B></P><P>Ethylene is a phytohormone involved in the regulation of several aspects of plant development and in responses to biotic and abiotic stress. The effects of exogenous application of ethylene to sugarcane plants are well characterized as growth inhibition of immature internodes and stimulation of sucrose accumulation. However, the molecular network underlying the control of ethylene biosynthesis in sugarcane remains largely unknown. The chemical reaction catalyzed by 1-aminocyclopropane-1-carboxylic acid synthase (ACS) is an important rate-limiting step that regulates ethylene production in plants. In this work, using a yeast one-hybrid approach, we identified three basic helix-loop-helix (bHLH) transcription factors, homologs of Arabidopsis FBH (FLOWERING BHLH), that bind to the promoter of <I>ScACS2</I> (Sugarcane <I>ACS2</I>), a sugarcane type 3 ACS isozyme gene. Protein–protein interaction assays showed that sugarcane FBH1 (ScFBH1), ScFBH2, and ScFBH3 form homo- and heterodimers in the nucleus. Gene expression analysis revealed that <I>ScFBHs</I> and <I>ScACS2</I> transcripts are more abundant in maturing internodes during afternoon and night. In addition, Arabidopsis functional analysis demonstrated that FBH controls ethylene production by regulating transcript levels of <I>ACS7</I>, a homolog of <I>ScACS2</I>. These results indicate that ScFBHs transcriptionally regulate ethylene biosynthesis in maturing internodes of sugarcane.</P></▼2>

In vitro response of rat microglia and human polymorphonuclear cells (PMN) to immunoactive compounds

Lombardi, Valter RM,Eetcheverria, Ignacio,Fernandez-Novoa, Lucia,Diaz, Joaquin,Seoane, Silvia,Cacabelos, Ramon Kyung Hee Oriental Medicine Research Center 2005 Oriental pharmacy and experimental medicine Vol.5 No.3

Although the field of study in immune enhancing compounds is relatively new, natural products from plants represent a rich and promising source of novel molecules with immunomodulating properties, Microglial cells, the main immune effector cells of the brain, usually display a ramified morphology and low expression levels of immunologically relevant antigens such as MHC class I and class II. Since any compound which participates in activation of phagocytic cells contributes to the production of potentially toxic factors, the search for convenient in vitro test-systems and study of mechanisms of action of these agents are of great interest. Human blood polymorphonuclear (PMN) cells and primary microglial cells isolated from Sprague-Dawley rats were used as cellular screening tests for study of phagocytosis-stimulating action of immunomodulating agents. Numbers of phagocytic activity were evaluated by the phagocyte ingestion of yeast cells and NO-synthase activity, nitrite production, and nitroblue tetrazolium test were determined after phagocyte stimulation. It was possible to demonstrate that indexes of phagocytic activity can be used as quantitative indicators for measurement immunomodulating activity. As a positive control, Zymosan A-induced phagocytosis in both PMN cells and primary microglial cells was used. $IFN-{\gamma}$ (0.1 -1 U/ml) stimulated phagocytosis in PMN cells 1.2 times after 2 - 3 h incubation, although at higher concentrations (10 - 100 U/ml) it strongly inhibited phagocytosis. In a similar way, at higher concentrations, $IFN-{\gamma}$ (100 - 500 U/ml) suppressed phagocytosis in zymosan-A stimulated microglial cells. When Polypodium leucotomus, cambricum and vulgare extracts were tested alone, increased levels of phagocytosis were observed in PMN. In addition, microglial cells showed both increased phagocytosis and MHC class-II antigen expressions. Surprisingly, when PMN and microglia were treated with a combination of Polypodium and $IFN-{\gamma}$, phagocytosis was not inhibited. We did not find changes in NO-synthase activity and nitrite production in both microglia and PMN cells activated by different immunomodulating agents. These results indicate that primary microglial cell cultures as well as human PMN cells can provide reproducible quantitative results in screening phagocytic activity of different immunoactive compounds. Furthermore, both inhibitory or activation mechanisms might be studied using these in vitro experimental approaches.

Smart Detection and Classification of Application-Layer Intrusions in Web Directories

Goran Bujas,Marin Vukovi?,Valter Vasi?,Miljenko Mikuc 한국산학기술학회 2015 SmartCR Vol.5 No.6

The Republic of Croatia homepage and directory of Croatian web servers (www.hr) attracts several thousand visitors daily, which makes it the target of various attacks. In order to lower the risk from such attacks, we propose a concept for an intrusion detection system and a classifier of detected intrusions. We first examined the concepts of existing intrusion detection systems and combined their individual benefits into a concept best suited for protecting web services on the application layer. The proposed concept uses machine learning techniques for both intrusion detection and classification. Intrusion detection, observed through analysis of requests, is implemented by a feed-forward neural network, while intrusion classification is done using self-organizing maps. The case study and preliminary evaluation is presented on the Republic of Croatia homepage (www.hr), followed by guidelines for further research.

Delay Dependent Local Stabilization Conditions for Time-delay Nonlinear Discrete-time Systems Using Takagi-Sugeno Models

Luís F. P. Silva,Valter J. S. Leite,Eugênio B. Castelan,Gang Feng 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.3

We propose convex conditions for stabilization of nonlinear discrete-time systems with time-varying delay in states through a fuzzy Takagi-Sugeno (T-S) modeling. These conditions are developed from a fuzzy Lyapunov-Krasovskii function and they are formulated in terms of linear matrix inequalities (LMIs). The results can be applied to a class of nonlinear systems that can be exactly represented by T-S fuzzy models inside a specific region called the region of validity. As a consequence, we need to provide an estimate of the set of safe initial conditions called the region of attraction such that the closed-loop trajectories starting in this set are assured to remain in the region of validity and to converge asymptotically to the origin. The estimate of the region of attraction is done with the aid of two sets: one dealing with the current state, and the other concerning the delayed states. Then, we can obtain the feedback fuzzy control law depending on the current state, xk, and the maximum delayed state vector, xk-d. It is shown that such a control law can locally stabilize the nonlinear discrete-time system at the origin. We also develop convex optimization procedures for the computation of the fuzzy control gains that maximize the estimates of the region of attraction. We present two examples to demonstrate the efficiency of the developed approach and to compare it with other approaches in the literature.

Phenomenological approaches for quantitative temperature-programmed reduction (TPR) and desorption (TPD) analysis

Simoní Da Ros,Karen Aline Valter Flores,Marcio Schwaab,Elisa Barbosa-Coutinho,Nádia R.C. Fernandes,José Carlos Pinto 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.94 No.-

Temperature-programmed reduction (TPR) and temperature-programmed desorption (TPD) aretechniques widely used for catalyst characterization, providing information about active sites. However,results from these experiments are usually interpreted with the aid of empirical models, based on therepresentation of reduction or desorption profiles as summations of empirical reference curves. In thiscontext, phenomenological approaches can present several advantages over this traditional empiricalapproach, as in this case the extracted information can be based on theoretical models that allows for adeeper understanding of the catalyst properties. For this reason, in the present work, empirical andphenomenological modelling approaches are evaluated for the quantitative analysis of H2-TPR and NH3-TPD profiles, obtained from the characterization of Ni/SiO2 and Al2O3 alumina catalysts, respectively, andresults from both approaches are thoroughly compared and discussed for thefirst time. Our results,obtained from thefitting of both modelling approaches to the whole experimental profile by usingnonlinear regression, indicate that the phenomenological modelling approach can be considered betterand should therefore be preferred, as it allows for significantly more accurate quantification and correctdiscrimination of distinct active sites, in addition to simultaneously enabling the determination ofreduction or desorption kinetics parameters.

Stability of 2-D Discrete Systems in the Presence of Saturation Function and Delays

Suchitra Pandey,Siva Kumar Tadepalli,Rishi Nigam,Valter J. S. Leite,Surekha Bhusnur 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.3

A variety of economically relevant processes are better modeled by using two-dimensional (2-D) models, which is the case, for instance, in metal rolling and the pharmaceutical industries. Typically Roesser and Fornasini Marchesini Local State Space (FMSLSS) models incorporate delayed states leading to a challenging stability analysis task. The main contribution of this work is to provide new convex stability analysis criteria for discrete-time FMSLSS models under both saturating function and time-varying delays. In particular, the saturating function tailors the digital control behavior, capturing the effect of finite wordlength. With Wirtinger and reciprocally convex sum lemmas, these new conditions can achieve less conservative results than other recent literature methods. Consequently, as illustrated by examples, this proposal enlarges the class of systems that can be stable-certified, still keep reasonable the associated computational effort.

Cuphea calophylla var. mesostemon (Koehne) S.A. Graham: A Whole-Ethnopharmacological Investigation

Lislaine Maria Klider,Camila Dias Machado,Valter Paes de Almeida,Cleide Adriane Signor Tirloni,Aline Aparecida Macedo Marques,Rhanany Alan Calloi Palozi,Bethânia Rosa Lorençone,Paulo Vitor Moreira Rom 한국식품영양과학회 2021 Journal of medicinal food Vol.24 No.4

Several species of Cuphea are used medicinally and are reported to have cardioprotective, diuretic, and antihypertensive properties. In Brazil, Cuphea species are collectively called “sete-sangrias” due to their similar appearances and are also used interchangeably for the same therapeutic purposes. So the aim of the study was to characterize morphoanatomy of leaves and stems, evaluate the safety, and investigate the diuretic, hypotensive, vasodilatory, and antioxidant properties of ethanol-soluble fraction of Cuphea calophylla var. mesostemon (Koehne) S.A. Graham. Initially, the morphoanatomical characterization of the leaves and stems of C. calophylla var. mesostemon was performed. For the pharmacological evaluation, the ethanol-soluble fraction from Cuphea calophylla (ESCC) was obtained and chemically characterized by high-performance liquid chromatography coupled with a diode array detector and tandem mass spectrometry techniques. Then, acute toxicity, diuretic, hypotensive, antioxidant, and vasodilatory effects were evaluated in Wistar rats. The main chemical compounds identified from ESCC were gallic acid derivatives, ellagitannins, and flavonoids. ESCC showed no acute toxic effect. ESCC showed no acute toxic effect and the estimated median lethal dose (LD50) was above 2000 mg/kg. ESCC treatment (30, 100, and 300 mg/kg) did not present any significant acute diuretic or hypotensive effects. However, an important reduction in the elimination of electrolytes was observed after the acute administration, and a significant increase in renal sodium elimination was observed after 7 days of treatment. In the cardiac tissue, the groups treated with ESCC presented significant increase in superoxide dismutase activity.