Investigación en Matemáticas, Economía, Ciencias Sociales y Agronomía

Cada trabajo del libro incluye conclusiones para los interesados en las temáticas aludidas y en ellos nos enteramos de aspectos como los siguientes: - El mayor incremento del precio de los insumos como el maíz, sorgo y en menor medida desperdicio de pan, en relación con el menor crecimiento del precio del ganado en pie, dará como consecuencia un desabasto de carne bovina. - El agua es un recurso primordial en las zonas áridas y semiáridas de México, en tanto que su aporte limita la producción de la agricultura. En este estudio se observó que el precio real del agua es muy bajo en relación a otras zonas agrícolas del mundo. - Hoy en día en el país se consumen alrededor de 718 mil barriles diarios de gasolinas, un aproximado de 113.7 millones de litros, una cantidad tan grande que nuestro país se ve en la necesidad de importar cerca del 39 % de las gasolinas que consumimos. - Los jaliscienses radicados en Estados Unidos tienen una mayor capacidad de financiamiento del bienestar en la entidad, que el propio gobierno de ese estado. - México continuará basando sus finanzas públicas y su política de desarrollo económico en la extracción de combustibles fósiles (petróleo). Este modelo acelerará el deterioro y agotamiento de los recursos naturales. -La importancia de la agricultura orgánica radica en que retoma los tres ámbitos de la sustentabilidad; el ámbito ambiental, el económico y el social. - Es fundamental motivar la organización de los productores de haba para que ellos puedan captar una mayor proporción de los altos márgenes de precios que los consumidores están dispuestos a pagar. - Las condiciones del clima afectan a la producción agraria. Debido al fenómeno de cambio climático, es necesario contar con herramientas informáticas que proporcionen información climatológica para poder tomar medidas preventivas a favor de una mayor cantidad y calidad de producción. La herramienta de software permite la consulta del clima por localidades evitando la necesidad de contar con una estación meteorológica

On an Efficient and Scalable Architecture for Mimicry Attacks Detection Using Probabilistic Methods-Edición Única

An intrusion detection system (IDS) aims at signalling an alarm for every ac- tivity that compromises a secure state of an IT system. It often amounts to detecting a known pattern of computer misuse, a deviation to ordinary, ex- pected user behaviour, or a combination thereof. Regardless of which of these approaches is adopted, current Intrusion Detection Systems (IDSs) are easy to bypass. This thesis addresses about the three most important limitations of existing IDSs: i) current IDSs are easily overwhelmed by the the amount of information they ought to analyse; ii) current IDSs are not sufficient to monitor dynamic environments where the monitored services are changed according to the needs of the organisation; and iii) current IDSs are easy to bypass using a mimicry attack (attacks that simulate normal sequences of system calls). These kinds of attacks simulate normal activity (eg traffic, interaction) by varying an attack signature in a way that does not affect the harmfulness of the attack. Instead of creating a lightweight detection method capable of dealing with large volumes of information, at the probable cost of loss of accuracy, we focus on making intrusion detection more tractable, scalable and efficient (without compromising accuracy). We make intrusion detection more tractable by pre- processing the information. Whether it is a sequence of network packets or a sequence of system calls, the information an IDS analyses is often redundant in at least, two respects: first, every entry in the sequence may contain spurious information; second, any sequence may contain redundant subsequences. To make probabilistic intrusion detection more scalable, efficient and flexible, we propose a novel architecture that includes a service selection mechanism. Instead of analysing a single stream of data, the stream is partitioned in services, each of which is analysed by a very specialised sensor. New sensors can be added on demand; if a new service needs to be monitored another sensor is placed. T o make mimicry attack intrusion detection more accurate (reduce false positives) we propose to divide attacks into smaller segments. For each segmentwe will create a detector that classifies the segment and all its variants. By combining these smaller detectors we hope to detect all variations of an attack. By using rough sets we have identified key attributes to eliminate spu- rious information, without missing chief details. Using n-gram theory we have identified the most redundant subsequences within a sequence, substi- tution of these subsequences with a fresh tag results in a reduction of the sequence length. To approach service selection, we suggest the use of hid- den Markov models (HMMs), trained to detect a specific service described by a family of n-gram.s In this thesis, we introduce a method which is ca- pable of successfully detecting a significant, interesting sub-class of mimicry attacks. The key behind our method's effectiveness lies on the use of a word network [Pereira and Riley, 1997, Young et al., 2002]. A word network conve- niently decomposes a pattern matching problem into a chain of smaller, noise- tolerant pattern matchers, thereby making it more tractable and robust. A word network is realised as a finite state machine, where every state is an HMM. In our experiments, our mechanism shows an accuracy of 93%. .By contrast., the rate of false positive occurrence is only 3%. Our log reduction methods are among the best in reduction ratio and features a minimal loss of information. Ours is one of the first techniques to successfully detect a sub-class of mimicry attacks

Efectos de un remolino de mesoescala sobre la distribución de larvas de peces mesopelágicas en el Golfo de California

We examined the effect of a mesoscale cyclonic eddy on the three-dimensional distribution of Vinciguerria lucetia and Diogenichthys laternatus in southern Gulf of California during July 2010. CTD data and zooplankton samples collected with a closing-opening net (505 µm), were obtained on 2 transects across the eddy, and on a transect outside of the mesoscale structure. In the later the thermocline depth was at ~40 m where larvae V. lucetia dominated. Opposite to V. lucetia distribution, D. laternatus larvae was the dominant species in the deepest strata. In the area influenced by the cyclonic eddy (~350 m depth and ~60 km diameter), the thermocline was sunk from ~25 m (eddy edge) to ~50 m depth (eddy center). The isotherms below the thermocline formed a dome from ~350 m to ~100 m depth in the eddy center. This upwelling coincided with an increase of D. laternatus larvae in the water column. Compared with the transect outside of the cyclonic eddy, the shoaling of the isotherms inside the eddy produced not only an increase of D. laternatus larvae, also decreased the V. lucetia abundance. These variations in larval distribution of both mesopelagic species are closely correlated with the mesoscale cyclonic eddy

Transcriptomic landscape of prophase I sunflower male meiocytes

Meiosis is a form of specialized cell division that generates gametes, allowing recombination of alleles and halving the chromosome number. Arabidopsis and maize are the plant models that have been most extensively studied to determine the genes involved in meiosis. Here we present an RNA-seq study in which gene expression in male meiocytes isolated during prophase I was compared to that in somatic tissues of the sunflower HA89 line. We sampled more than 490 million gene tags from these libraries, assembled them de novo into a sunflower transcriptome. We obtained expression data for 36,304 sunflower genes, of which 19,574 (54%) were differentially expressed between meiocytes and somatic tissue. We also determined the functional categories and metabolic pathways that are differentially expressed in these libraries. As expected, we found large differences between the meiotic and somatic transcriptomes, which is in accordance with previous studies in Arabidopsis and maize. Furthermore, most of the previously implicated meiotic genes were abundantly and differentially expressed in meiocytes and a large repertoire of transcription factors and genes related to silencing are expressed in the sunflower meiocytes. We detected transcription factors which appear to be exclusively expressed in meiocytes. Our results allow for a better understanding of the conservation and differences in the meiotic transcriptome of plants