Influencia de factores fósicos y químicos sobre la sobrevivencia de Pichia aislada de jarabe de glucosa

Yeasts belonging to the genus Pichia were isolated fr om glucose syrup samples. Yeasts were identified as P. anomala ( it is now Wickerhamomyces anomala) and P. guilliermondii. These strains did not metabolize the nutritive preservatives, potassium sorbate or sodium benzoate when these were used as the single carbon source. P. anomala grew in culture media containing up to 1200 mg/L of both preservatives. Critical temperature and time of exposure for its inactivation were 60 °C and 3 min, respectively. P. guilliermondii grew in media containing up to 1400 mg/L of both preservatives. Critical temperature and time for inactivation of this Pichia were 80 °C and 2 min. This strain was able to grow in a wide range of temperatures (5 to 30 °C), pH (2.5 to 5.5) and glucose concentrations (200 to 800 g/L). At 5 °C and 800 g/L glucose (osmotic pressure, 0.110 atm), P.guilliermndii gr ew poorly , with no cell death because of its ability to sporulate. We determined that P. guilliermondii is a potentially contaminating yeast able to develop in a variety of foods, especially those with low pH or with high sugar concentrations (glucose above 400g/L) such as refreshments, juices, syrups and confected fruits and it is resistant to both food preservatives and low temperatures (5°C).De muestras de jarabe de glucosa fueron aisladas levaduras que pertenecen al género Pichia. Estas fueron identificadas como P.anomala (actualmente Wickerha- momyces anomala) y P. guilliermondii, ambas cepas no metabolizan los conservantes alimenticios, sorbato de potasio o benzoato de sodio, al ser usados como única fuente de carbono. P. anomala desarrolló en medios de cultivo que contenían hasta 1200 mg/L de ambos conservantes. La temperatura y el tiempo crítico de exposición para su inactivación fueron 60 °C y 3 min, respectiva- mente. P.guilliermondii desarrolló en medios que contienen hasta 1400 mg/l de ambos conservantes. La to y el tiempo crítico de inactivación fueron 80 °C y 2 min. Esta cepa fue capaz de desarrollar en un amplio rango de temperaturas (5 a 30 °C), pH (2,5 a 5,5) y concentraciones de glucosa (200 a 800 g/L). A 5 °C y glucosa 800 g/L (presión osmótica, 0,110 atm), P. guilliermondii desarrolló pobremente sin que se produzca la muerte celular debido a su capacidad de esporular. Se deter- minó que P. guilliermondii, es una levadura potencialmente contaminante que puede desarrollarse en una variedad de alimentos, especialmente aquellos con bajo pH o altas concentraciones de azúcar (glucosa, > 400 g/L) como en gaseosas, jugos, jarabes y frutas confitadas, y es resistente a ambos conservantes y bajas to (5°C)Fil: Rubio, María Cristina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Biotecnología; ArgentinaFil: Navarro, Antonio Roberto. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentin

Modulo scheduling for a fully-distributed clustered VLIW architecture

Clustering is an approach that many microprocessors are adopting in recent times in order to mitigate the increasing penalties of wire delays. We propose a novel clustered VLIW architecture which has all its resources partitioned among clusters, including the cache memory. A modulo scheduling scheme for this architecture is also proposed. This algorithm takes into account both register and memory inter-cluster communications so that the final schedule results in a cluster assignment that favors cluster locality in cache references and register accesses. It has been evaluated for both 2- and 4-cluster configurations and for differing numbers and latencies of inter-cluster buses. The proposed algorithm produces schedules with very low communication requirements and outperforms previous cluster-oriented schedulers.Peer ReviewedPostprint (published version

The effectiveness of loop unrolling for modulo scheduling in clustered VLIW architectures

Clustered organizations are becoming a common trend in the design of VLIW architectures. In this work we propose a novel modulo scheduling approach for such architectures. The proposed technique performs the cluster assignment and the instruction scheduling in a single pass, which is shown to be more effective than doing first the assignment and later the scheduling. We also show that loop unrolling significantly enhances the performance of the proposed scheduler especially when the communication channel among clusters is the main performance bottleneck. By selectively unrolling some loops, we can obtain the best performance with the minimum increase in code size. Performance evaluation for the SPECfp95 shows that the clustered architecture achieves about the same IPC (Instructions Per Cycle) as a unified architecture with the same resources. Moreover when the cycle time is taken into account, a 4-cluster configurations is 3.6 times faster than the unified architecture.Peer ReviewedPostprint (published version

Fast, accurate and flexible data locality analysis

This paper presents a tool based on a new approach for analyzing the locality exhibited by data memory references. The tool is very fast because it is based on a static locality analysis enhanced with very simple profiling information, which results in a negligible slowdown. This feature allows the tool to be used for highly time-consuming applications and to include it as a step in a typical iterative analysis-optimization process. The tool can provide a detailed evaluation of the reuse exhibited by a program, quantifying and qualifying the different types of misses either globally or detailed by program sections, data structures, memory instructions, etc. The accuracy of the tool is validated by comparing its results with those provided by a simulator.Peer ReviewedPostprint (published version

Using microelectrode models for real time cell-culture monitoring

This paper proposes a cell-microelectrode model for cell biometry applications, based on the area overlap as main parameter. The model can be applied to cell size identification, cell count, and their extension to cell growth and dosimetry protocols. Experiments performed with comercial electrodes are presented, illustrating a procedure to obtain cell number in both growth and dosimetry processes. Results obtained for the AA8 cell line are promising.Junta de Andalucía P0-TIC-538

Worldwide Research on Plant Defense against Biotic Stresses as Improvement for Sustainable Agriculture

Agriculture is the basis for food production on a global scale. Sustainable agriculture tries to improve or maintain the quality of food without compromising the environment. As sessile organisms, plants cannot avoid adverse environmental conditions and contact with other living organisms. The damage caused to plants by other living organisms such as parasites and pathogens (virus, bacteria, fungi, nematodes or insects) brings about what is known as biotic stress. Plants are constantly exposed to biotic stress, which causes changes in plant metabolism involving physiological damages that lead to a reduction of their productivity. To fight biotic stress, plants have developed sophisticated defense mechanisms. Thus, understanding plant defense mechanisms might prevent important crop and economic losses. In this article, a bibliometric analysis of biotic stress is carried out. Different aspects of the publications are analyzed, such as publication type, research field, journal type, countries and their institutions, as well as the keyword occurrence frequency, and finally special attention is paid to the plant studied by the leading countries and institutions. As expected, journals selected by authors to publish their relevant findings are plant-specific journals. However, it should be noted that the fourth position, in terms of the number of publications per journal, is occupied by BMC Genomics journal. Such a journal considers mainly articles on genomics, which indicates the involvement of genetic factors in the control of biotic stress. Analysis of the keywords used in publications about biotic stress shows the great interest in the biotic–abiotic stress interaction, in the gene expression regulation in plants as well as phytohormones in the current research. In short, the great effort made by the scientific community in the biotic and abiotic stresses field with the aim to understand, regulate and control plant damages caused by biotic stress agents will help in the development of sustainable agriculture

Inteligencia ambiental: entornos inteligentes ante el desafío de los procesos inferenciales

Information and Communication Technologies (ICT) are intended to develop, maintain and administrate information using computer systems, communication networks, portable dispositives, etc. In addition to that, this paper deals with ICT’s power to create new contexts: what is called digital ambiences. According to the author the design and even the concept of these intelligent ambiences has problems that have to do both with the use of reasoning and the display of inferential and interpretative processes to interact with the social context in an individual or a collective way. Solving these philosophical problems could guide the development and implantation of ubiquitous and embodied technologies that would be able to amplify the cognitive and motive capacity of people.Las tecnologías de la información y la comunicación (TIC) están concebidas para el desarrollo, mantenimiento y administración de la información por medio de sistemas informáticos, redes de telecomunicaciones, dispositivos portátiles, etc. Sin embargo, en este trabajo se insiste en su poder para generar una nueva modalidad de entorno: los llamados ambientes digitales. La autora plantea que el diseño y aun el concepto de inteligencia ambiental presenta problemas especulativos relacionados con el empleo de razonamientos y el despliegue de procesos inferenciales e interpretativos a través de los cuales interactuamos con el entorno social tanto individual como colectivamente. La resolución de estos problemas filosóficos podría orientar el desarrollo y la implantación de las tecnologías embebidas y ubicuas, capaces de amplificar la capacidad cognitiva y motriz de las personas

Classification of some nilpotent class of leibniz superalgebras

The aim of this work is to present the description of Leibniz superalgebras up to isomorphism with characteristic sequence (n|m − 1, 1) and nilindex n + m

Triazole-Directed Pd-Catalyzed C(sp2)–H Oxygenation of Arenes and Alkenes

Selective Pd-catalyzed C(sp2)–H oxygenation of 4-substituted 1,2,3-triazoles is described. Unlike previous metal-catalyzed C–H functionalization events, which preferentially occur at the activated heterocyclic C–H bond, the regioselective oxygenation of the arene/alkene moiety is now achieved featuring the unconventional role of a simple triazole scaffold as a modular and selective directing group.MINECO for a Ramon y Cajal research contract (RYC-2012-09873)

Dudas razonables, sesgos cognitivos y emociones en la argumentación jurídica: el caso de "Doce hombres sin piedad"

Concepts as reasonable doubt, cognitive biases and emotions are now a theoretical problem for the practice of law, and the law understood as legal argumentation. From a theoretical point of view, the screenplay written by Reginald Rose, Twelve Angry Men, is an outstanding example to analyze some of these concepts, and its influence on procedural stage. Cognitive biases and informal fallacies are theoretical challenge to legal argumentation.La noción de duda razonable, los sesgos cognitivos y las emociones son en la actualidad un problema para la práctica del derecho y para el derecho entendido como argumentación. El guión de Reginald Rose, Twelve Angry Men es un ejemplo excepcional para analizar algunos de esos conceptos y observar su influencia en un escenario procesal de un valor teórico y cinematográfico incuestionables. Las predisposiciones cognitivas, las falacias informales, los sesgos cognitivos de confirmación y de disconformidad suponen en un desafío teórico para la lógica jurídica