Development of novel antibacterial active, HaCaT biocompatible and biodegradable CA-g-P(3HB)-EC biocomposites with caffeic acid as a functional entity

We have developed novel composites by grafting caffeic acid (CA) onto the P(3HB)-EC based material and laccase from Trametes versicolor was used for grafting purposes. The resulting composites were designated as CA-g-P(3HB)-EC i.e., P(3HB)-EC (control), 5CA-g-P(3HB)-EC, 10CA-g-P(3HB)-EC, 15CA-g-P(3HB)-EC and 20CA-g-P(3HB)-EC. An FT-IR (Fourier-transform infrared spectroscopy) was used to examine the functional and elemental groups of the control and laccase-assisted graft composites. Evidently, 15CA-g-P(3HB)-EC composite exhibited resilient antibacterial activity against Gram-positive and Gram-negative bacterial strains, respectively. Moreover, a significant level of biocompatibility and biodegradability of the CA-g-P(3HB)-EC composites was also achieved with the human keratinocytes-like HaCaT cells and soil burial evaluation, respectively. In conclusion, the newly developed novel composites with multi characteristics could well represent the new wave of biomaterials for medical applications, and more specifically have promising future in the infection free would dressings, burn and/or skin regeneration field due to their sophisticated characteristics.

A comprehensive simulation study of slotted CSMA/CA for IEEE 802.15.4 wireless sensor networks

In this paper, we analyze the performance limits of the slotted CSMA/CA mechanism of IEEE 802.15.4 in the beacon-enabled mode for broadcast transmissions in WSNs. The motivation for evaluating the beacon-enabled mode is due to its flexibility for WSN applications as compared to the non-beacon enabled mode. Our analysis is based on an accurate simulation model of the slotted CSMA/CA mechanism on top of a realistic physical layer, with respect to the IEEE 802.15.4 standard specification. The performance of the slotted CSMA/CA is evaluated and analyzed for different network settings to understand the impact of the protocol attributes (superframe order, beacon order and backoff exponent) on the network performance, namely in terms of throughput (S), average delay (D) and probability of success (Ps). We introduce the concept of utility (U) as a combination of two or more metrics, to determine the best offered load range for an optimal behavior of the network. We show that the optimal network performance using slotted CSMA/CA occurs in the range of 35% to 60% with respect to an utility function proportional to the network throughput (S) divided by the average delay (D).

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in Portugal:

Methicillin-resistant Staphylococcus aureus (MRSA), a human pathogen confined to hospitals (HAMRSA) for over 30 years have been emerging worldwide in the last two decades as a leading cause of severe infections in healthy individuals in the community (CA-MRSA). Despite its clinical significance, in the beginning of our studies no information existed on the prevalence, and population structure of CA-MRSA in Portugal. Moreover, it remained to be clarified how CA-MRSA emerged in our country. In particular, it was not known if CA-MRSA emerged locally by acquisition of the staphylococcal cassette chromosome mec (SCCmec) by established methicillin-susceptible S. aureus (MSSA) in the community, if they were imported from abroad or have escaped from the hospital.(...)

Improving TCP Performance on CSMA/CA Connections

In IP networks, most of packets, that have been dropped, are recovered after the expiration of retransmission timeouts. These can result in unnecessary retransmissions and needless reduction of congestion window. An inappropriate retransmission timeout has a huge impact on TCP performance. In this paper we have proved that CSMA/CA mechanism can cause TCP retransmissions due to CSMA/CA effects. For this we have observed three wireless connections that use CSMA/CA: with good link quality, poor link quality and in presence of cross traffic. The measurements have been performed using real devices. Through tracking of each transmitted packet it is possible to analyze the relation between one-way delay and packet loss probability and the cumulative distribution of distances between peaks of OWDs. The distribution of OWDs and the distances between peaks of OWDs are the most important parameters of tuning TCP retransmission timeout on CSMA/CA networks. A new perspective through investigating the dynamical relation between one-way delay and packet loss ratio depending on the link quality to enhance the TCP performance has been provided.

Revue des livres anciens : documents d'histoire littéraire, de bibliographie & de bibliophilie / direction Pierre Louÿs ; rédaction Louis Loviot

1914 (T1).

Revue des livres anciens : documents d'histoire littéraire, de bibliographie & de bibliophilie / direction Pierre Louÿs ; rédaction Louis Loviot

1917 (T2).

Sondages de l'opinion publique française / Service de sondages et statistiques ; Comité directeur Pascal Copeau, Pierre Hervé, Yvon Morandat, Max Barioux

1944/05/23 (N2).

Sondages de l'opinion publique française / Service de sondages et statistiques ; Comité directeur Pascal Copeau, Pierre Hervé, Yvon Morandat, Max Barioux

1944/06/26 (N6).

Sondages de l'opinion publique française / Service de sondages et statistiques ; Comité directeur Pascal Copeau, Pierre Hervé, Yvon Morandat, Max Barioux

1944/09/15.

Sondages de l'opinion publique française / Service de sondages et statistiques ; Comité directeur Pascal Copeau, Pierre Hervé, Yvon Morandat, Max Barioux

1944/05/28 (N3).

Sondages de l'opinion publique française / Service de sondages et statistiques ; Comité directeur Pascal Copeau, Pierre Hervé, Yvon Morandat, Max Barioux

1944/07/10 (N10).

Sondages de l'opinion publique française / Service de sondages et statistiques ; Comité directeur Pascal Copeau, Pierre Hervé, Yvon Morandat, Max Barioux

1944/09/04 (N13).

Sondages de l'opinion publique française / Service de sondages et statistiques ; Comité directeur Pascal Copeau, Pierre Hervé, Yvon Morandat, Max Barioux

1944 (NTABLE).