Modelado de las curvas de supervivencia de E.Coli en bebidas refrescantes y en preparados lácteos (modelo Baranyi)

E. coli O157:H7 es un microorganismo perteneciente a la familia Enterobacteriaceae. Forma parte de la flora normal del intestino del hombre y de los animales de sangre caliente; está implicada en una serie de enfermedades transmitidas por los alimentos, causando brotes de colitis hemorrágica y síndrome urémico hemolítico. Entre los alimentos implicados se incluyen carnes elaboradas y cocidas de manera insuficiente, frutas y hortalizas crudas, productos lácteos y zumos de frutas no pasteurizados. Se ha aplicado el modelo matemático de Baranyi y Roberts (1994) para la estimación de los parámetros de supervivencia de Escherichia coli no patógeno CECT 516 (EC) y Escherichia coli O157:H7 CECT 4076 y CECT 4267 (ECO) en Bebidas refrescantes comerciales y Preparados lácteos comerciales pasteurizados a 4 y 20ºC. El modelo permite estimar el tiempo de latencia, la velocidad máxima de decrecimiento y la población final. A 20ºC el tiempo necesario en no detectarse células viables fue de 3-5 días en el caso de las Bebidas refrescantes tipo A y B, y de 6-17 días en el caso de los Preparados lácteos tipo A y B. A 4ºC el tiempo necesario fue de 7 días en el caso de las Bebidas refrescantes tipo A y B y de 11- 24 días en el caso de los Preparados lácteos Tipo A y B. El tiempo necesario para no detectarse células viables es menor a 20ºC que a 4ºC; a su vez es menor en las Bebidas refrescantes que en los Preparados lácteos. Dentro de los distintos tipos de Bebidas refrescantes y Preparados lácteos la inactivación del microorganismo es más rápida en los Tipo A que en los Tipo B. En los Preparados lácteos el tiempo en inactivar EC fue menor que en inactivar ECO mientras que en las Bebidas refrescantes no hubo diferencias significativas en el tiempo empleadoGrado en Nutrición Humana y Dietétic

Torii HLMAC: distributed, fault-tolerant, zero configuration data center architecture with multiple tree-based addressing and forwarding

Proceedings of: 7th International Conference on emerging Networking EXperiments and Technologies (CoNEXT). ACM CoNEXT 2011 Student Workshop. Tokyo, Japan, December 6-9, 2011.This paper describes Torii-HLMAC a scalable, fault-tolerant, zero-configuration data center network fabric architecture (currently under final evaluation) as a full distributed alternative to Portland for similar multiple tree (fat tree) network topologies. It uses multiple, fixed, tree-based positional MAC addresses, used for multiple path table-free forwarding. Addresses are assigned by simple extension of the Rapid Spanning Tree Protocol. Torii-HLMAC enhances the Portland protocol advantages of scalability, zero configuration and high performance and adds instant path recovery, distributed address assignment. ARP broadcast may use ARP Proxy.This work is supported in part by grants from Comunidad de Madrid and Comunidad de Castilla la Mancha through Projects MEDIANET-CM (S-2009/TIC- 1468) and EMARECE (PII1I09-0204-4319).Publicad

Torii-HLMAC: A distributed, fault-tolerant, zero configuration fat tree data center architecture with multiple tree-based addressing and forwarding

Proceedings of: IEEE Global Communications Conference (GLOBECOM 2012). Anaheim, California, USA. December 03-07, 2012.This paper describes Torii-HLMAC, a scalable, fault-tolerant, zero-configuration data center network fabric architecture protocol as a fully distributed alternative to PortLand for similar multiple tree network topologies. It uses multiple, fixed, tree-based positional MAC addresses for multiple path and table-free forwarding. Addresses are assigned by a simple extension of the Rapid Spanning Tree Protocol. Torii-HLMAC enhances the PortLand protocol advantages of scalability, zero configuration and high performance and adds instant path recovery, fully distributed routing and address assignment. ARP Proxy may be used to avoid ARP broadcast messages.This work was supported in part by grants from Comunidad de Madrid and Comunidad de Castilla la Mancha through Projects MEDIANET-CM (S-2009/TIC-1468) and EMARECE (PII1I09-0204-4319).Publicad

All-path bridging: Path exploration as an efficient alternative to path computation in bridging standards

This work is at: IEEE International Conference on Communications: Second Workshop on Telecommunication Standards: From Research to Standards. In Communications Workshops (ICC). Date 9-13 June 2013, Budapest, Hungary.Link-state based routing protocols are dominant in Shortest Path Bridges (IEEE 802.1aq) and also at TRILL (IETF) Rbridges. Both standards propose a hybrid of switch and router adding a link state routing protocol in layer two that computes shortest paths between bridges. Surprisingly, path exploration mechanisms have not yet been considered at standardization bodies, in spite of some outstanding advantages: simplicity,instantaneous path adaptation to traffic load with load adaptive routing and low latency. We have developed All-path, a family of protocols based on simple path exploration mechanisms based on full flooding of a single frame, as an alternative to the "beatentrail" of path computation. Path exploration (either instantaneous or periodical, proactive or reactive) is an efficient alternative to path computation for bridged networks because the processing cost of address learning at bridges from broad cast frames is very low and Ethernet links provide very high link capacity so that the extra packet broad casts do not impact load significantly. Standardization groups should consider the application of path exploration (instantaneous or periodical, proactive or reactive) mechanisms in Audio Video Bridges and ingeneric bridging networks like campus and data centers to find redundant paths, low latency and load distributionThis work was supported in part by grants from Comunidad de Madrid through Project MEDIANET-CM (S-2009/TIC-1468) .Publicad