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Signaling modulation in cells that control gastrointestinal motility

RAUL LOERA VALENCIA (2014)

"La vida es sustentada en parte por la actividad motora del tracto gastrointestinal. Los patrones de motilidad en dicho tracto son orquestados por la interacción de mecanismos reguladores neurogénicos y miogénicos. Las neuronas mientéricas modulan el reflejo peristáltico a través de circuitos neurales, mientras que las células intersticiales de Cajal (ICC) controlan la generación de oscilaciones rítmicas de voltaje en el músculo liso conocidas como ondas lentas. Las neuronas mientéricas y las ICC modulan su actividad por la señalización de neurotransmisores y su acción sobre la apertura/cierre de canales iónicos. En este trabajo usamos técnicas moleculares para tratar problemas particulares en la señalización de neuronas mientéricas y las ICC. Las neuronas mientéricas usan el ATP como neurotransmisor excitatorio a través de receptores P2X, sin embargo la presencia de P2X3 no parece intervenir en la fisiología normal de la motilidad en el intestino delgado de cobayos. Proponemos que su función se da durante el desarrollo postnatal. Nuestros resultados muestran una reducción en el número de neuronas mientéricas positivas a P2X 3 durante el desarrollo postnatal y el incremento de neuronas P2X 5 positivas en los adultos. La aparición de neuronas P2X2 y P2X4 positivas permaneció estable. La sensibilidad al ATP de neuronas neonatales y adultas no cambió. Las ICC de ratón pueden participar en la modulación de la motilidad colónica a través de señalización muscarínica colinérgica. Nuestros resultados indican que dicha señ alización bloqueó la actividad de canales K+ en cultivos primarios de ICC. La aplicación de un bloqueador de Kv7 también bloqueó la actividad de estos canales y activó un maxicanal en las ICC. RT-PCR de célula única y doble inmunotinción de cólones de ratón revelaron ICC-IM Kv7.5 positivas inervadas por fibras colinérgicas. Sugerimos ampliar el uso de las técnicas moleculares para tratar problemas básicos en la motilidad gastrointestinal."

"Life is sustained in part by the motor activity of the gastrointestinal tract. The motility patterns in the gastrointestinal tract are orchestrated by the interplay of neurogenic and myogenic governing mechanisms. The myenteric neurons modulate the peristaltic reflex through circuits of sensory, motor and interneurons, while interstitial cells of Cajal (ICC) pace the generation of rhythmic voltage oscillations in the smooth muscle known as slow waves. Both system s act together to generate diverse motility patterns in the gut. Myenteric neurons and interstitial cells of Cajal modulate their activity through signaling of neurotransmitters and its effect on the gating of ionic channels. In this work we use diverse molecular techniques to address particular problems in the signalling of myenteric neurons and interstitial cells of Cajal. M yenteric neurons use ATP as excitatory neurotransmitter through P2X receptor signalling, however the presence of P2X 3 does not play a role in the normal physiology of guinea pig small intestinal motility. We propose this subunit has a function in postnatal development. Our results show reduction of P2X3 positive myenteric neurons during postna tal development and increase of P2X5 positive neurons to adulthood, whilst appearance of P2X 2 and P2X4 remained unchanged. This regulation does not alter ATP sensibility in cultured neurons from neonatal or adult guinea pigs. Murine colonic ICC could participate in the modulation of colon motility through muscarinic cholinergic signalling; we provide experimental evidence showing that muscarinic stimulation of ICC blocked K + channel activity in primary cultures. The application of a Kv7 blocker also abolished this activity and activated a maxi channel in ICC. Single cell RT-PCR and double immunostaining of colons revealed Kv7.5 positive ICC-IM and its dense cholinergic innervation. We suggest expanding the use of molecular techniques to approach basic physiological problems in gut motility."

Doctoral thesis

P2X3 ATP Myenteric neurons Kv7 channels ICC Colonic motitlity BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA MOLECULAR

Application of Spectral Decomposition Methods to the Definition of Stratigraphic Features Associated with Channel Reservoirs in the Southeast Petroleum Province, México

FERNANDO ALVAREZ SAN ROMAN (2018)

Spectral decomposition transforms seismic data into

the frequency domain via mathematical methods such as the discrete

Fourier transform, S-transform, time–frequency continuous

wavelet transform and continuous wavelet transform. The transformed

results include tuning cubes and a variety of discrete

common frequency cubes, which reveal structural and stratigraphic

features, such as channels, thin bed reflections, and subtle faults.

When a spectral decomposition algorithm is applied to seismic

reflection data, it breaks down the seismic signal into its frequency

components and this allows visualization of the data at specific

frequencies, and identification of stratigraphic and structural features

that would otherwise be overlooked in full bandwidth

displays. The stratigraphic features delineated through the different

algorithms, such as channels and their sedimentary facies, could be

related to the presence of reservoir rock, i.e., underground rock

units where the oil migrates and accumulates. An example from the

Southeast Petroleum Province in México is presented.

Article

CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA Spectral decomposition channels discrete Fourier transform S-transform time–frequency continuous wavelet transform continuous wavelet transform

EXPLORATION OF ORNAMENTAL PLANT MARKETING CHANNELS. CHIHUAHUA´S VIVERISTS

ANGELA YUMIL ROMERO MOZQUEDA MARIA TERESA ALARCON HERRERA (2017)

Ornamental plants are a highly valued product in many parts of the world, due to their sensorial

characteristics, support for biodiversity and occupation of labor. Mexico is one of the important producers in

the world, also distinguished by good quality products. The objective of this exploratory study is to present a

framework of opportunities to strengthen the commercialization of ornamentals and structure distribution

channels according to the needs of the local consumer, in which interviews and documentary research propose

different solutions for the association of producers In question, for decision-making and strategy development.

The conclusions propose the actions to be undertaken by the floriculture companies studied in order to increase

their competitiveness

Conference proceedings

Marketing channels BIOLOGÍA Y QUÍMICA QUÍMICA QUÍMICA FÍSICA OTRAS

The multipath fading and the frequency response of the channel in an indoor radiating cable system

JORGE ALBERTO SESEÑA OSORIO (2014)

The use of wireless handheld devices has increased in recent years, at the same time; the data transmission rate rises exponentially. This trend has led to a greater concentration of mobile devices in specific locations, such as office buildings, shopping centers, airports, sports stadiums, etc. In this context, the next generation of wireless services must be able to develop ubiquitous ultra-broadband speeds. Hence, solutions are required for overcoming the hurdles present at these locations in order to satisfy the user requirements. In this regard, dedicated systems are an alternative for providing wireless services at indoor environments, while also allowing performance improvement and the possibility of offering tailored services for specific environments. In this context, radiating cables have been used as alternative distribution systems for indoor environments where distributed antenna systems have limitations giving full coverage due to obstacles (walls, doors, furniture, etc.) between the receiver and transmitter. Such scenarios generate challenges on the study and design of these radiating cable systems – for example, issues involved in the wireless communication channel.

Doctoral thesis

Multipath channels Indoor wireless communication Telecommunication cables CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ELECTRÓNICA

Análisis de la cadena de valor queso de hebra en el municipio de Vega de Alatorre, Veracruz.

INGRID LILIANA GÓMEZ HUESCA (2020)

Tesis (Maestría en Ciencias, especialista en Agroecosistemas Tropicales).- Colegio de Postgraduados, Campus Veracruz, 2020.

El queso de hebra es uno de los productos lácteos más consumidos en México, debido a la variedad de platillos elaborados con este tipo de queso dentro de la gastronomía mexicana. El objetivo de la investigación fue analizar la cadena de valor queso de hebra en el municipio de Vega de Alatorre, Veracruz; para identificar a cada uno de los agentes que conforman la cadena, así como los canales de comercialización y los márgenes de ganancia de la misma. Para ello se identificó y caracterizó a cada uno de los agentes que conforman la cadena, así como su integración, los canales de comercialización de la misma y el margen de ganancia en función del volumen de producción a través de los enfoques de Sistemas Agroalimentarios Localizados (SIAL) y de cadena de valor. Los resultados encontrados muestran que los agentes que participan en la cadena de valor son proveedores, ganaderos, recolectores, queseros, comerciantes y consumidor final; se encontraron cinco canales de comercialización y el margen de ganancia varió de acuerdo al volumen de producción de cada quesería aunado al nivel tecnológico, fuentes de la materia prima, estrategias de mercado y precio de venta. Para gran productor ($14.21), mediano productor ($11.23), pequeño productor ($10.65). El queso de hebra es el de mayor producción en el municipio de Vega de Alatorre por ser el más comercial. _______________ ANALYSIS OF THE VALUE CHAIN OF THE HEBRA CHEESE IN THE MUNICIPALITY OF VEGA DE ALATORRE, VERACRUZ. ABSTRACT: Strand cheese is one of the most consumed dairy products by the population, due to the variety of dishes made with this type of cheese in Mexican cuisine. The objective of the research was to analyze the links of the strand cheese value chain in the municipality of Vega de Alatorre, Veracruz. For this, each of the agents that make up the chain was identified and characterized, as well as its integration, its commercialization channels and the profit margin based on the volume of production through the Localized Agrifood Systems approaches (SIAL) and Value Chain. The results found show that the agents participating in the value chain are suppliers, ranchers, gatherers, cheese makers, merchants and final consumers;it is concluded that strand cheese production is more as the production scale is increased; its production being smaller in the small producer and the structure of the agents is semi-integrated.

Master thesis

Sistemas Agroalimentarios Localizados Canales de comercialización Margen de ganancia Costos de producción Localized Agrifood Systems Marketing channels Profit margin Production costs Agroecosistemas Tropicales Maestría INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE LOS ALIMENTOS ELABORACIÓN DE ALIMENTOS

Highly-Linear/Highly-Efficient CMOS power amplifier for mobile WiMAX

LUIS ABRAHAM SANCHEZ GASPARIANO (2011)

The present work is about the design of a power amplification system in

CMOS technology which satisfies the demands established by the IEEE802.16e-

2005 standard for mobile WiMAX.

The simulation in CadenceVirtuoso v5.0.0. of the complete power amplification

stage with the UMC 0.18μm Mixed Mode and RF CMOS technology

was carried out. The RF band for which the circuit was tuned to operate was

between 2.496GHz and 2.69GHz with an LO signal running from 2.486GHz to

2.68GHz and a BB signal of 10MHz. The power supply for the predriver stage

was of 1.8V and 0.9V for the amplification stage. The total power consumption

of the circuit was of approximately 26dBm. The peak output power obtained was

23dBm with a drain efficiency, ηD, of 83% and a Power Added Efficiency, PAE, of

61% meanwhile for 12dB of output power back-off the ηD was 33% and the PAE

31%. The harmonic suppression around the carrier in a range of 194MHz at from

2.496GHz to 2.69GHz presents a minimum value of -55dBc. These results indicate

that the proposed multipath polyphase Power Amplifier exhibits both, a high

linearity achieving until -60dBc of intermodulation suppression with respect to

the frequency of interest, (ωLO + ωBB), within the mobile WiMAX bandwidth,

and a high PAE at peak output power and with 12dB of output power back-off.

In addition, the design and fabrication of the predriver stage was also realized

but in a double poly three metal layers 0.5μm CMOS technology from MOSIS

foundry. The fabricated prototype area was 0.472μm × 0.148μm. The prototype

was characterized with an LO frequency of 80MHz and a BB frequency of 1.6MHz.

The power supply was of 3.3V. The tuning control was of 400mV ranging from

1.0V to 1.4V. The maximum power consumption was 14.5dBm and the minimum

was 12.6dBm. The maximum output power was 6.5dBm meanwhile the minimum

was 0.3dBm. The duty cycle of the prototype was modifiable in a range of 9.3%

from 49.4% to 40.1%. Finally, the maximum pulse amplitude of the output signal

was 1V and the minimum pulse amplitude covers from 950mV to 200mV. According

to these results, we conclude that the behavior of the predriver stage follows

the curse anticipated in the synthesis. This is very important since the predriver

stage is the key building block to enhance the efficiency of the overall system.

Doctoral thesis

RF amplifiers Power amplifiers Wireless channels CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ELECTRÓNICA

An efficient causal protocol with forward error correction for mobile distributed systems

EDUARDO LOPEZ DOMINGUEZ SAUL EDUARDO POMARES HERNANDEZ GUSTAVO RODRIGUEZ GOMEZ MARIA AUXILIO MEDINA NIETO JOSE ANTONIO MUÑOZ GOMEZ (2010)

Problem statement: Causal ordering is used in Mobile Distributed Systems (MDS) to reduce the non-determinism induced by four main aspects: host mobility, asynchronous execution, unpredictable communication delays and unreliable communication channels. Some causal protocols have been proposed for MDS. All of these protocols in order to ensure the causal order in unreliable channels use the method of Automatic Repeat Request (ARQ). They detect a lost message and carry out the retransmission of this message. This approach was not recommended in a real time mobile distributed system because it increased the transmission delay of the data and the overhead sent in the communication channels. Approach: In this study, we proposed a protocol that ensured the causal order of messages in unreliable and asynchronous MDS. In our protocol, the detection and recovery of lost messages was achieved by the method of Forward Error Correction (FEC) in a distributed form. One interesting aspect of our Causal-FEC protocol was that the redundant information sent in the wired and wireless communication channels is dynamically adapted to the behavior of the system. Results: Our protocol was efficient in terms of the overhead attached per message, the computational cost and the storage control information at a mobile host. Conclusion: The present study is one of the first works on causal algorithms based on forward error recovery in mobile networks.

Article

Causal ordering Unreliable channels Causal distance FEC CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA MATEMÁTICAS CIENCIA DE LOS ORDENADORES CIENCIA DE LOS ORDENADORES

Canales de potasio (MAXI-K y K ATP ) en la actividad eléctrica neuronal

JUAN JOSE ACEVEDO FERNANDEZ (2001)

En este trabajo se estudia la participación de los canales de potasio activados por calcio y la de los sensibles ATP en la actividad eléctrica de las neuronas secretoras del acocil Procambarus clarkii (crustáceo decápodo). Se describe y discute la participación de cada canal en el potencial de membrana, así como su contribución relativa en la corriente saliente total. Los registros del potencial de membrana y de la corriente total de la célula fueron obtenidos mediante la técnica de parche perforado con nistatina en dos modos de registro: fijación de corriente y fijación de voltaje, respectivamente.

Book

BIOLOGÍA Y QUÍMICA Channels, Potassium Calcium Calcio Neuronas Procambarus clarkii

Powering the plasma membrane Ca2+-ROS self-amplifying loop

IGOR POTTOSIN ALBERTO ISAAC ZEPEDA JAZO (2018)

Reactive oxygen species (ROS) and intracellular Ca2+ signaling interact with and amplify each other: the major ROSproducing plasma membrane enzyme NADPH-oxidase (NOX) is activated by cytosolic Ca2+, and in turn ROS activate Ca2+ influx across the plasma membrane. For the latter, NOX-produced superoxide anions need to be converted to hydroxyl radicals. Makavitskaya et al. (2018) have now demonstrated that salt stress promotes ascorbate efflux, which, via reduction of the apoplastic copper and iron ions, assists in the generation of hydroxyl radicals, thus inducing a rise in intracellular Ca2+ in the roots.

Article

BIOQUÍMICA Anion channels Anion current Arabidopsis Ascorbate Ca2+ signaling Cytosolic Ca2+ Hydroxyl radical NADPH oxidase ROS