Diffie-Hellman Protocol Based on Elgamal and AES Cryptosystems

Abstract : -This paper presents a communication scheme design for securing messages through local area networks (LAN). This scheme implements a hybrid cryptosystem which is formed by AES-256 in its symmetric part and ElGamal for encryption of keys where the prime has 400 digits and 200 digits for the alpha primitive. It also applies the Diffie-Hellman protocol for key secure distribution. This implementation is targeted at senior management members or groups of any corporate trust where the number of users is small. Key distribution requires a number equal to the number of rounds for at least one user

Planeación del riego en el cultivo de algodonero (Gossypium hirsutum L.), mediante un modelo de programación integral en el Distrito 075, Sinaloa, México

Cotton crops were one of the most important during the 50 and 80 decades in Northern Sinaloa, Mexico from the economical point of view. However, external factors such as monoculture and sanitary issues caused its disappearance. Due to the need of diversifying the actual pattern of crops grown in the zone, a great possibility of re-growing cotton crop exists. Actually, there is lack of updated information about irrigation and agronomic management practices of the crop. In order to contribute to a new crop planning, an integral programming model was used to estimate planting dates and windows as well as irrigation planning at different operation levels. Field experiments were conducted at different locations of northern Sinaloa during the growing season 2011-2012 in Ahome and Guasave counties. Each plot had a dimension of 2 hectares and five varieties grown with the purpose of calibrating the integral model to then realize a set of simulations with seven planting dates, estimate water requirements and length of growing season as well. At the end of the season (harvest) 2400 growing degree days were accumulated (100% open balls) for local conditions, water requirements were 500 mm for the month of July, 870 mm for October, after that it declined to a point of 690 mm for crops planted in January.El cultivo de algodonero en las décadas de los 50´s y 80´s fue uno de los más importantes en los valles agrícolas del norte de Sinaloa, México desde el punto de vista económico. Sin embargo, factores como su monocultivo y problemas fitosanitarios provocaron su desaparición. Ante la necesidad de diversificar el patrón actual de cultivos sembrados en la zona, existe la posibilidad de reintroducir el cultivo, sin embargo, se carece de información actualizada sobre riegos y manejo agronómico. Con el fin de contribuir a una nueva planeación del cultivo se utilizó un modelo integral de programación de riego con el cual se estimaron la ventana de siembras y la planeación del riego a diferentes niveles de operación hidráulica. Experimentos de campo se condujeron durante el ciclo agrícola otoño-invierno 2011-2012 en tres localidades del norte de Sinaloa en los municipios de Ahome y Guasave, en cada parcela se establecieron cinco variedades en una superficie de dos hectáreas con el propósito de calibrar el modelo para posteriormente realizar una serie de simulaciones en siete fechas de siembra y estimar los requerimientos hídricos y duración del ciclo. Al final del ciclo se obtuvo una acumulación de 2400 GDA (Grados de días acumulados) (100% de bellotas abiertas) para condiciones locales, un requerimiento hídrico de 500 mm para el mes de Julio y 870 mm para el mes de Octubre, después de este disminuyen nuevamente las necesidades hídricas llegando a 690 mm para siembras del mes de Enero

Immunology and Oxidative Stress in Multiple Sclerosis: Clinical and Basic Approach

Multiple sclerosis (MS) exhibits many of the hallmarks of an inflammatory autoimmune disorder including breakdown of the blood-brain barrier (BBB), the recruitment of lymphocytes, microglia, and macrophages to lesion sites, the presence of multiple lesions, generally being more pronounced in the brain stem and spinal cord, the predominantly perivascular location of lesions, the temporal maturation of lesions from inflammation through demyelination, to gliosis and partial remyelination, and the presence of immunoglobulin in the central nervous system and cerebrospinal fluid. Lymphocytes activated in the periphery infiltrate the central nervous system to trigger a local immune response that ultimately damages myelin and axons. Pro-inflammatory cytokines amplify the inflammatory cascade by compromising the BBB, recruiting immune cells from the periphery, and activating resident microglia. inflammation-associated oxidative burst in activated microglia and macrophages plays an important role in the demyelination and free radical-mediated tissue injury in the pathogenesis of MS. The inflammatory environment in demyelinating lesions leads to the generation of oxygen- and nitrogen-free radicals as well as proinflammatory cytokines which contribute to the development and progression of the disease. Inflammation can lead to oxidative stress and vice versa. Thus, oxidative stress and inflammation are involved in a self-perpetuating cycle

Cloning, in silico structural characterization and expression analysis of MfAtr4, an ABC transporter from the banana pathogen Mycosphaerella fijiensis

ABC transporters are membrane proteins that use the energy released from the hydrolysis of ATP to drive the transport of compounds across biological membranes. In some plants, pathogenic fungi ABC transporters play a role as virulence factors by mediating the export of plant defense compounds or fungal virulence factors. Mycosphaerella fijiensis, the causal agent of black Sigatoka disease in banana, is the main constraint for the banana industry worldwide. So far, little is known about molecular mechanism that it uses to infect the host. In this study, degenerated primers designed from fungal ABC transporters known to be involved in virulence were used to isolate homologs from M. fijiensis. Here, we reported the full cloning of MfAtr4 a putative ortholog of MgAtr4, an ABC transporter of the related Mycosphaerella graminicola with a function in virulence. Similarities and differences with its presumed ortholog MgAtr4 are described, and the putative function of MfAtr4 are discussed. Analysis of MfAtr4 gene expression in field banana samples exhibiting visible symptoms of black Sigatoka disease indicated a higher expression of MfAtr4 during the first symptomatic stages in comparison to the late necrotrophic phases, suggesting a role for MfAtr4 in the early stages of pathogenic development of M. fijiensis.Key words: ABC transporters, virulence factors, MgAtr4 ortholog, Mycosphaerella fijiensis, black Sigatoka, Musa sp

The diversity and evolution of pollination systems in large plant clades: Apocynaceae as a case study

Background and Aims Large clades of angiosperms are often characterized by diverse interactions with pollinators, but how these pollination systems are structured phylogenetically and biogeographically is still uncertain for most families. Apocynaceae is a clade of >5300 species with a worldwide distribution. A database representing >10 % of species in the family was used to explore the diversity of pollinators and evolutionary shifts in pollination systems across major clades and regions. Methods The database was compiled from published and unpublished reports. Plants were categorized into broad pollination systems and then subdivided to include bimodal systems. These were mapped against the five major divisions of the family, and against the smaller clades. Finally, pollination systems were mapped onto a phylogenetic reconstruction that included those species for which sequence data are available, and transition rates between pollination systems were calculated. Key Results Most Apocynaceae are insect pollinated with few records of bird pollination. Almost three-quarters of species are pollinated by a single higher taxon (e.g. flies or moths); 7 % have bimodal pollination systems, whilst the remaining approx. 20 % are insect generalists. The less phenotypically specialized flowers of the Rauvolfioids are pollinated by a more restricted set of pollinators than are more complex flowers within the Apocynoids + Periplocoideae + Secamonoideae + Asclepiadoideae (APSA) clade. Certain combinations of bimodal pollination systems are more common than others. Some pollination systems are missing from particular regions, whilst others are over-represented. Conclusions Within Apocynaceae, interactions with pollinators are highly structured both phylogenetically and biogeographically. Variation in transition rates between pollination systems suggest constraints on their evolution, whereas regional differences point to environmental effects such as filtering of certain pollinators from habitats. This is the most extensive analysis of its type so far attempted and gives important insights into the diversity and evolution of pollination systems in large clades

Planeación del riego en el cultivo de algodonero (Gossypium hirsutum L.), mediante un modelo de programación integral en el Distrito 075, Sinaloa, México.

El cultivo de algodonero en las décadas de los 50's y 80's fue uno de los más importantes en los valles agrícolas del norte de Sinaloa, México desde el punto de vista económico. Sin embargo, factores como su monocultivo y problemas fitosanitarios provocaron su desaparición. Ante la necesidad de diversificar el patrón actual de cultivos sembrados en la zona, existe la posibilidad de reintroducir el cultivo, sin embargo, se carece de información actualizada sobre riegos y manejo agronómico. Con el fin de contribuir a una nueva planeación del cultivo se utilizó un modelo integral de programación de riego con el cual se estimaron la ventana de siembras y la planeación del riego a diferentes niveles de operación hidráulica. Experimentos de campo se condujeron durante el ciclo agrícola otoño-invierno 2011-2012 en tres localidades del norte de Sinaloa en los municipios de Ahome y Guasave, en cada parcela se establecieron cinco variedades en una superficie de dos hectáreas con el propósito de calibrar el modelo para posteriormente realizar una serie de simulaciones en siete fechas de siembra y estimar los requerimientos hídricos y duración del ciclo. Al final del ciclo se obtuvo una acumulación de 2400 GDA (Grados de días acumulados) (100% de bellotas abiertas) para condiciones locales, un requerimiento hídrico de 500 mm para el mes de Julio y 870 mm para el mes de Octubre, después de este disminuyen nuevamente las necesidades hídricas llegando a 690 mm para siembras del mes de Enero.Cotton crops were one of the most important during the 50 and 80 decades in Northern Sinaloa, Mexico from the economical point of view. However, external factors such as monoculture and sanitary issues caused its disappearance. Due to the need of diversifying the actual pattern of crops grown in the zone, a great possibility of re-growing cotton crop exists. Actually, there is lack of updated information about irrigation and agronomic management practices of the crop. In order to contribute to a new crop planning, an integral programming model was used to estimate planting dates and windows as well as irrigation planning at different operation levels. Field experiments were conducted at different locations of northern Sinaloa during the growing season 2011-2012 in Ahome and Guasave counties. Each plot had a dimension of 2 hectares and five varieties grown with the purpose of calibrating the integral model to then realize a set of simulations with seven planting dates, estimate water requirements and length of growing season as well. At the end of the season (harvest) 2400 growing degree days were accumulated (100% open balls) for local conditions, water requirements were 500 mm for the month of July, 870 mm for October, after that it declined to a point of 690 mm for crops planted in January

Kinetics of the Thermal Decomposition of Rhodochrosite

Manganese is a widely used element in the steel industry; its main source is a mineral named rhodochrosite (MnCO3). For industrial usage, rhodochrosite is reduced to different manganese oxides by means of nodulation furnaces. In this study, rhodochrosite was thermally analyzed at temperatures ranging from 100 °C to 1200 °C. XRD (Powder X-ray diffraction), XRF (X-ray fluorescence), AAS (Atomic Absorption Spectrometry), and FESEM-EDX (Field Emission Scanning Electron Microscopy-Energy Dispersive X-ray Spectrometry) were used to characterize the mineral and the residues were analyzed by XRD and FTIR (Fourier-transform infrared spectroscopy) to determine the stoichiometry of the thermal decomposition reactions. Three mass losses were observed, the first attributed to the transformation from carbonate to manganese (III) oxide, the second to the reduction to manganese tetroxide, and the third to the decomposition of calcium carbonate (CaCO3) present as a contaminant in the studied mineral. Thermal decomposition kinetics shows that the first mass loss required 17.91 kJ mol−1, indicating a control by mass transport-controlled process. For the second and third mass loss, the apparent activation energy of 112.41 kJ mol−1 and 64.69 kJ mol−1 was obtained respectively, indicating that both mass loss events were rate-controlled

Planeación del riego en el cultivo de algodonero (Gossypium hirsutum L.), mediante un modelo de programación integral en el Distrito 075, Sinaloa, México

Cotton crops were one of the most important during the 50 and 80 decades in Northern Sinaloa, Mexico from the economical point of view. However, external factors such as monoculture and sanitary issues caused its disappearance. Due to the need of diversifying the actual pattern of crops grown in the zone, a great possibility of re-growing cotton crop exists. Actually, there is lack of updated information about irrigation and agronomic management practices of the crop. In order to contribute to a new crop planning, an integral programming model was used to estimate planting dates and windows as well as irrigation planning at different operation levels. Field experiments were conducted at different locations of northern Sinaloa during the growing season 2011-2012 in Ahome and Guasave counties. Each plot had a dimension of 2 hectares and five varieties grown with the purpose of calibrating the integral model to then realize a set of simulations with seven planting dates, estimate water requirements and length of growing season as well. At the end of the season (harvest) 2400 growing degree days were accumulated (100% open balls) for local conditions, water requirements were 500 mm for the month of July, 870 mm for October, after that it declined to a point of 690 mm for crops planted in January.El cultivo de algodonero en las décadas de los 50´s y 80´s fue uno de los más importantes en los valles agrícolas del norte de Sinaloa, México desde el punto de vista económico. Sin embargo, factores como su monocultivo y problemas fitosanitarios provocaron su desaparición. Ante la necesidad de diversificar el patrón actual de cultivos sembrados en la zona, existe la posibilidad de reintroducir el cultivo, sin embargo, se carece de información actualizada sobre riegos y manejo agronómico. Con el fin de contribuir a una nueva planeación del cultivo se utilizó un modelo integral de programación de riego con el cual se estimaron la ventana de siembras y la planeación del riego a diferentes niveles de operación hidráulica. Experimentos de campo se condujeron durante el ciclo agrícola otoño-invierno 2011-2012 en tres localidades del norte de Sinaloa en los municipios de Ahome y Guasave, en cada parcela se establecieron cinco variedades en una superficie de dos hectáreas con el propósito de calibrar el modelo para posteriormente realizar una serie de simulaciones en siete fechas de siembra y estimar los requerimientos hídricos y duración del ciclo. Al final del ciclo se obtuvo una acumulación de 2400 GDA (Grados de días acumulados) (100% de bellotas abiertas) para condiciones locales, un requerimiento hídrico de 500 mm para el mes de Julio y 870 mm para el mes de Octubre, después de este disminuyen nuevamente las necesidades hídricas llegando a 690 mm para siembras del mes de Enero

Synthesis of New <i>bis</i> 1- and 5-Substituted 1<i>H</i>-Tetrazoles via Huisgen-Type 1,3-Dipolar Cycloadditions

The synthesis and characterization of one symmetrical bis-1-substituted-1H-tetrazole (69%) via a Huisgen-type 1,3-dipolar cycloaddition, as well as, one symmetrical aza-linked bis-5-substituted-1H-tetrazole (57%) via a classic Huisgen 1,3-dipolar cycloaddition followed by a reductive aza-coupling under greener reaction conditions are described. The main reason behind these tetrazole-based ligands is to construct novel Metal-Organic Framework (MOF) architectures to evaluate their CO2 capture properties under relative humidity conditions. It is worthy to note that both herein reported products have not been synthesized nor isolated, anywhere. Besides, the synthesis of new ligands to fabricate novel MOFs with potential application in environmental remediation has become a highly valued field of opportunity for synthetic chemists and materials engineers