Lightweight Mutual Authentication Protocol for Low Cost RFID Tags

Radio Frequency Identification (RFID) technology one of the most promising technologies in the field of ubiquitous computing. Indeed, RFID technology may well replace barcode technology. Although it offers many advantages over other identification systems, there are also associated security risks that are not easy to be addressed. When designing a real lightweight authentication protocol for low cost RFID tags, a number of challenges arise due to the extremely limited computational, storage and communication abilities of Low-cost RFID tags. This paper proposes a real mutual authentication protocol for low cost RFID tags. The proposed protocol prevents passive attacks as active attacks are discounted when designing a protocol to meet the requirements of low cost RFID tags. However the implementation of the protocol meets the limited abilities of low cost RFID tags.Comment: 11 Pages, IJNS

The effect of gonadotropin-releasing hormone analogues on the preservation of ovarian function against cyclophosphamide-induced damage in adult mice

Objective: To assess the effect of gonadotropin-releasing hormone analogue (GnRHa) on the preservation of ovarian function against cyclophosphamide-induced gonadal toxicity. Materials and Methods: In a controlled, experimental study, 64 female mice were divided into four groups: control (C), triptorelin acetate (T), cyclophosphamide (CY), and triptorelin plus cyclophosphamide (T+CY) groups. Mice in the group (T) were subcutaneously injected with GnRHa (triptorelin acetate) in a dose of 0.5 mg/kg daily for 21 days. In contrast, mice in the (CY) group and (T+CY) group were injected intraperitoneally with 75 mg/kg of CY on day 15. After 21 days, half of the mice in each group were sacrificed, and their ovaries were removed. The rest of the mice in each group were left without any intervention for an additional 21 days, and the same procedures were repeated to assess the ovarian follicles. Results: There was significant depletion of ovarian follicles in the CY group compared to the control group (p<0.05). There were significant decreases in the number of secondary and antral follicles at late stage as compared to early stage in the CY group (p<0.05). There was also a significant increase in the number of primordial and primary follicles in the T+CY group as compared with the CY group early post-treatment, while the increase was significant in all follicles after 42 days (p<0.05). Conclusion: Cyclophosphamide destroys primordial and primary follicles at an early stage while damage in secondary and antral follicles was prominent after 42 days. Triptorelin acetate reduces the toxic effect of CY; it has early and late protective effects and preserves ovarian function in mice

Crystal structure of ethyl 2-[2-((1E)-{(1E)-2-[2-(2-ethoxy-2-oxoethoxy)benzyl-idene]hydrazin-1-ylidene}methyl)phen-oxy]acetate

NSF–MRI grant No. 1228232 for the purchase of the diffractometer and Tulane University for support of the Tulane Crystallography Laboratory are gratefully acknowledged.Peer reviewedPublisher PD

Suppressive efficiency of Kojic acid from Aspergillus tamarii MM11 against HepG-2 cell line derived from human liver cancer

Purpose: To evaluate the antioxidant and cytotoxic properties of Kojic acid (KOJIC ACID) from Aspergillus tamarii MM11 against HepG-2 cell line derived from human liver cancer.Methods: The crude extract of A. tamarii MM11 was dissolved in a mixture of CH2Cl2/MeOH (85:15) and separation was done using silica gel chromatography using gradient size exclusion chromatograph. The non-polar oily fractions were subjected to gas chromatography-mass&nbsp; spectrometric (GC-MS) analysis. Kojic acid structure was identified by x-beam crystallography and spectroscopic methods. Total antioxidant properties of KOJIC ACID were evaluated by using 1,1-diphenyl-2- picrylhydrazyl (DPPH) against ascorbic acid as a reference. The cytotoxic activity of KOJIC ACID from A. tamarii MM11 was investigated on the human cell line of liver cancer (HepG-2) using a sulforhodamine B (SRB) assay based on a cell density determination by the measurement of cellular protein content.Result: Highly bioactive Kojic acid was isolated as the main product. A. tamarii MM11 Kojic acid showed good antioxidant activity with half-maximal inhibitory concentration of IC50 at concentrations of 10.34 compared to 6.79 μg/mL for ascorbic acid. Kojic acid also showed good cytotoxic activity against HepG-2 cell line of human liver cancer with IC50 at 6.20 compared to 3.25 μg/mL of reference drug doxorubicin.Conclusion: Kojic acid produced naturally from A. tamarii MM11 shows good antioxidant and cytotoxic activity against HepG-2 cell line derived from&nbsp; human liver cancer. These findings suggest that Kojic acid can be therapeutically used as an antitumor drug after further in vivo studies. Keywords: Aspergillus tamarii, Secondary metabolites, Kojic acid, Anticancer, Liver cance

2-(Morpholin-4-yl)-6-(1H-pyrrol-1-yl)­pyridine-3,5-dicarbonitrile

In the title compound, C15H13N5O, the morpholine ring adopts a chair conformation. The dihedral angle between the pyrrole ring and the pyridine ring is 28.93 (14)°. In the crystal, the molecules are linked by C—H⋯O hydrogen bonds occur, and aromatic weak π–π stacking [centroid–centroid separation = 4.178 (2) Å] and C—H⋯π inter­actions consolidate the packing

2-Amino-6-(dimethyl­amino)pyridine-3,5-dicarbonitrile

The title compound, C9H9N5, is slightly twisted from planarity, with a maximum deviation of 0.0285 (13) Å from the pyridine plane for the C atom bearing the amino group. The cyano groups are on different sides of the pyridine plane, with C- and N-atom deviations of 0.072 (3)/0.124 (4) and −0.228 (4)/−0.409 (5) Å from the pyridine plane. In the crystal, N—H⋯N and C—H⋯N hydrogen bonds connect the mol­ecules into zigzag chains running along the c axis

2-(Piperidin-1-yl)-6-(1H-pyrrol-1-yl)pyridine-3,5-dicarbonitrile

The piperidine ring of the title compound, C16H15N5, adopts a chair conformation. The pyridine ring is essentially planar, with a maximum deviation of 0.035 (3) Å. The pyrrole and pyridine rings are almost coplanar, forming a dihedral angle of 3.48 (14)°. In the crystal, no classical hydrogen bonds were found. In the crystal, the molecules are linked by aromatic π–π stacking [centroid–centroid separations = 3.4984 (16) and 3.9641 (15) Å between pyrrole and pyridine rings and between pyridine rings, respectively]

Les interactions entre les ressources, particulièrement les ressources digitales, et les conceptions des professeurs de biologie dans le cours de leur travail documentaire.: Le cas de l'enseignement du déterminisme génétique dans le secondaire au Liban

The purpose of this study is twofold: first, it aims to study the extent to which secondary Lebanese biology teachers use digital resources in their teaching in general and in teaching genetics in specific. Second, it aims to study the relation between the use of digital resources by teachers and their conceptions of genetic determinism of phenotype, particularly from hereditarianism to epigenetics. For the purpose of this study, a combination of two theoretical frameworks is used, namely, the “documentational approach” and the “KVP model”. A mixed methodology was designed, combining quantitative and qualitative research: a questionnaire, interviews, logbooks, schematic representation of the system of resources, SRSR, and classroom observations. Participants who filled out the questionnaire included 116 secondary Lebanese biology teachers from various regions in Lebanon. Based on the responses of the questionnaire, four teachers were purposefully selected for further studies, and two of them were followed for two successive years. The results showed that teachers in fact integrate digital resources in their teaching in order to facilitate students’ understanding of abstract genetics concepts and to enrich and update their own scientific knowledge. Moreover, findings indicated that availability and accessibility of technology, time availability, collective and collaborative work, technological proficiency and attitudes towards technology are all factors that influence teachers’ integration of digital resources. Results also revealed that the relation between resources and conceptions is reversible: teachers’ conceptions affect the choice and implementation of resources on one hand (instrumentalization) and teachers’ documentary work affects teachers’ conceptions on the other (instrumentation). Implications for practice and future research are discussed.Cette étude comprend deux objectifs: premièrement, elle vise à étudier dans quelle mesure les enseignants de biologie du secondaire, au Liban, utilisent les ressources numériques dans leur enseignement en général et dans l'enseignement du génétique en particulier. Deuxièmement, elle vise à étudier les relations entre l’usage de ressources numériques par les enseignants et leurs conceptions concernant le déterminisme génétique du phénotype, en particulier de l’héréditarisme de l'épigénétique. Aux fins de cette étude, une combinaison entre deux cadres théoriques a été utilisée, à savoir, "l'approche documentaire" et le modèle de "KVP". Une méthodologie mixte a été conçue, combinant des études quantitatives et qualitatives: un questionnaire, des entretiens, des journaux de bords, des représentations schématiques de systèmes de ressources (RSSR) et des observations de classe. Le terrain de recherche a impliqué 116 enseignants de biologie du secondaire de diverses régions libanaises. Sur la base des réponses au questionnaire, quatre enseignants ont été sélectionnés pour des études plus approfondies et deux parmi eux ont été suivi pendant deux années consécutives. Les résultats ont mis en évidence que les enseignants intègrent des ressources numériques dans leur enseignement pour favoriser la compréhension, par les élèves, de concepts abstraits en génétique et pour enrichir et mettre à jour leurs connaissances scientifiques. En outre, les résultats ont indiqué que la disponibilité et l'accessibilité de la technologie, la disponibilité du temps, le travail collectif et collaboratif, la maîtrise technologique et les attitudes envers la technologie sont autant des facteurs qui affectent l'intégration, par les enseignants, de ressources numériques. Les résultats ont également montré que la relation entre les ressources et les conceptions est réversible : les conceptions des enseignants affectent leur choix des ressources et leur intégration d'une part (instrumentalisation) et le travail documentaire des enseignants affecte leurs conceptions d'autre part (instrumentation). Les implications pour la pratique et les futures recherches sont discutées

Travail documentaire des enseignants de biologie au Liban et son interaction avec leurs conceptions sur le déterminisme génétique

International audienceThis study articulates two theoretical frameworks to identify their possible interactions: the documentational approach to analyze the documentary work of teachers, and the KVP model to study their conceptions about genetic determinism. Our combined methodology allowed the definition of critical resources and situations to infer conceptions. The results show that the conceptions of the two selected teachers, govern their choice of resources, also (digital) resources consolidate or might be the origin of their conceptions. Thus, the teacher of the public school that has outdated knowledge (K) on the genetic determinism that might reflect her innate values (V), has chosen in her practice (P) two resources applying hereditarianism model: the biology national textbook for grade 11 S (mobilized, and implemented critical resource) and a slide show (elaborated and implemented critical resource). However, her interactions with digital resources have helped in non-stabilized evolution in her conceptions toward epigenetic. The teacher in private school with a dynamic system of resources and updated knowledge (K) that might reflect her less innate values (V), grants a central place in her practice (P) to her digital archive that is constantly updated, and to a mobilized and implemented critical resource (French biology textbook Bordas, Grade 11, Scientific section) applying the epigenetic model.Cette étude articule deux cadres théoriques afin d’identifier leurs possibles interactions : l’approche documentaire pour analyser le travail documentaire des enseignants, et le modèle KVP pour étudier leurs conceptions sur le déterminisme génétique. Notre méthodologie a permis la définition de ressources et situations critiques susceptibles d’inférer ces conceptions. Les résultats montrent que les conceptions des deux enseignantes sélectionnées régiraient leur choix de ressources, et que les ressources (numériques) pouvaient agir sur leurs conceptions. Ainsi, l’enseignante de l’école publique, qui a des connaissances dépassées (K) sur le déterminisme génétique qui refléteraient ses valeurs innéistes (V), a choisi dans sa pratique (P) deux ressources appliquant le modèle héréditariste, le manuel de biologie libanais de 1re S (ressource critique mobilisée et implémentée) et un diaporama (ressource critique élaborée et implémentée). Cependant, ses interactions avec les ressources numériques ont permis un début d’évolution, non stabilisée, dans ses conceptions vers l’épigénétique. L’enseignante de l’école privée, avec un système de ressources dynamique et des connaissances actualisées (K) qui refléteraient ses valeurs (V) moins innéistes, accorde une place centrale dans sa pratique (P) à son archive numérique mise à jour en permanence, et à une ressource critique mobilisée et implémentée (le manuel de biologie Bordas de 1re S) appliquant le modèle épigénétique