Analysis of IPR curves in North Slope horizontal producers supported by waterflood and water alternating gas EOR processes

Master's Project (M.S.) University of Alaska Fairbanks, 2019The shape and behavior of IPR curves in waterflooded reservoirs has not previously been defined despite their common use for optimization activities in such systems. This work begins to define the behavior of IPR curves in both water flood and water‐alternating‐gas EOR systems using a fine scale model of the Alpine A‐sand. The behavior of IPRs is extended to 3 additional reservoir systems with differing mobility ratios. Traditionally derived (Vogel, Fetkovich) IPR curves are found to be poor representations of well performance and are shown to lead to non‐optimal gas lift allocations in compression limited production networks. Additionally, the seemingly trivial solution to gas lift optimization in an unconstrained system is shown to be more complex than simply minimizing the bottom hole pressure of the producing well; maximized economic value is achieved at FBHPs greater than zero psi

Hedonic Price Indexes for Personal Computer Operating Systems and Productivity Suites

Results of hedonic price regressions for personal computer operating systems and productivity suites advertised in PC World magazine by retail vendors during the time period 1984 to 2000 are reported. Among the quality attribute variables we use are new measures capturing the presence of network effects in personal computer operating systems, such as connectivity and compatibility, and product integration among components of productivity suites. Average annual growth rates of quality-adjusted prices of personal computer operating systems range from -15 to -18 percent, while those for productivity suites generally range between -13 and -16 percent. Price declines are generally greater in the latter half of the samples.

Propuesta de gestión del cambio basado en el modelo ADKAR en el Colegio Privado Jorge Basadre de la ciudad de Chiclayo

En la presente investigación estudiaremos al colegio Jorge Basadre de la ciudad de Chiclayo, el cual tiene algunos problemas para adaptarse al entorno cambiante que se ve en estos tiempos, puesto que, se aprecia demasiada rotación interna de personal, por lo cual, sus clientes no puedan acceder siempre al personal indicado o es que muchas veces tiene una deficiente respuesta ante los cambios dados por los entes del Estado, como el Ministerio de Educación, entre otros; debido a que muchas veces han tenido que hacer caso omiso a las disposiciones dadas por el gobierno. El objetivo general de la investigación es formular una propuesta de gestión del cambio basado en el modelo ADKAR en el colegio Jorge Basadre de Chiclayo, basada en un estudio con enfoque cuantitativo de alcance explicativo, con un diseño transversal y observacional. La misma que se realizará con una muestra de 80 colaboradores, en base al modelo ADKAR de Prosci, J. Hiatt, (2006), en el cuál se midió las 5 dimensiones con las que cuenta ADKAR, las cuales son: conciencia, deseo, conocimiento, habilidad y refuerzo, teniendo como técnica la encuesta y herramienta al cuestionario de acuerdo al modelo planteado. Teniendo como resultado relevante que se obtuvo que las dimensiones de conciencia y conocimiento fueron bajas, esto no quiere decir que los colaboradores desconozcan, sino que el grado de conocimiento es menor y como conclusión se tiene que modelo ADKAR es un modelo sensible que podemos trabajar varias dimensiones en una actividad de mejora, pudiéndose aplicar distintas organizaciones

Effect of the Synthetic Bile Salt Analog CamSA on the Hamster Model of Clostridium difficile Infection

Clostridium difficile infection (CDI) is the leading cause of antibiotic-associated diarrhea and has gained worldwide notoriety due to emerging hypervirulent strains and the high incidence of recurrence. We previously reported protection of mice from CDI using the antigerminant bile salt analog CamSA. Here we describe the effects of CamSA in the hamster model of CDI. CamSA treatment of hamsters showed no toxicity and did not affect the richness or diversity of gut microbiota; however, minor changes in community composition were observed. Treatment of C. difficile-challenged hamsters with CamSA doubled the mean time to death, compared to control hamsters. However, CamSA alone was insufficient to prevent CDI in hamsters. CamSA in conjunction with suboptimal concentrations of vancomycin led to complete protection from CDI in 70% of animals. Protected animals remained disease-free at least 30 days postchallenge and showed no signs of colonic tissue damage. In a delayed-treatment model of hamster CDI, CamSA was unable to prevent infection signs and death. These data support a putative model in which CamSA reduces the number of germinating C. difficile spores but does not keep all of the spores from germinating. Vancomycin halts division of any vegetative cells that are able to grow from spores that escape CamSA

Compartmentalized PDE4A5 signaling impairs hippocampal synaptic plasticity and long-term memory

Alterations in cAMP signaling are thought to contribute to neurocognitive and neuropsychiatric disorders. Members of the cAMP-specific phosphodiesterase 4 (PDE4) family, which contains >25 different isoforms, play a key role in determining spatial cAMP degradation so as to orchestrate compartmentalized cAMP signaling in cells. Each isoform binds to a different set of protein complexes through its unique N-terminal domain, thereby leading to targeted degradation of cAMP in specific intracellular compartments. However, the functional role of specific compartmentalized PDE4 isoforms has not been examined in vivo. Here, we show that increasing protein levels of the PDE4A5 isoform in mouse hippocampal excitatory neurons impairs a long-lasting form of hippocampal synaptic plasticity and attenuates hippocampus-dependent long-term memories without affecting anxiety. In contrast, viral expression of a truncated version of PDE4A5, which lacks the unique N-terminal targeting domain, does not affect long-term memory. Further, overexpression of the PDE4A1 isoform, which targets a different subset of signalosomes, leaves memory undisturbed. Fluorescence resonance energy transfer sensor-based cAMP measurements reveal that the full-length PDE4A5, in contrast to the truncated form, hampers forskolin-mediated increases in neuronal cAMP levels. Our study indicates that the unique N-terminal localization domain of PDE4A5 is essential for the targeting of specific cAMP-dependent signaling underlying synaptic plasticity and memory. The development of compounds to disrupt the compartmentalization of individual PDE4 isoforms by targeting their unique N-terminal domains may provide a fruitful approach to prevent cognitive deficits in neuropsychiatric and neurocognitive disorders that are associated with alterations in cAMP signaling

Gestión administrativa y satisfacción de los usuarios de la Municipalidad Distrital de San Marcos, Huari, Áncash, 2023

El objetivo es determinar la relación entre la gestión administrativa y la satisfacción de los usuarios en el distrito de San Marcos, Huari-Ancash, año 2023. Métodos: esta tesis es básico y su enfoque es cuantitativo. No experimental y transversal. Se evaluaron 375 usuarios; y se utilizó una escala Likert como medio para medir sus actitudes. Resultados: El nivel de GA es calificado como inadecuado por el 28% de los 375 usuarios encuestados, bueno por el 28% y normal por el 44%. Conclusión: En la municipalidad distrital de San Marcos existió una correlación positiva y alta (r=0,732) entre la GA y la satisfacción de los usuarios

Interaction of Solid Lipid Nanoparticles and Specific Proteins of the Corona Studied by Surface Plasmon Resonance

The applications of pharmaceutical and medical nanosystems are among the most intensively investigated fields in nanotechnology. A relevant point to be considered in the design and development of nanovehicles intended for medical use is the formation of the "protein corona" around the nanoparticle, that is, a complex biomolecular layer formed when the nanovehicle is exposed to biological fluids. The chemical nature of the protein corona determines the biological identity of the nanoparticle and influences, among others, the recognition of the nanocarrier by the mononuclear phagocytic system and, thus, its clearance from the blood. Recent works suggest that Surface Plasmon Resonance (SPR), extensively employed for the analysis of biomolecular interactions, can shed light on the formation of the protein corona and its interaction with the surroundings. The synthesis and characterization of solid lipid nanoparticles (SLN) coated with polymers of different chemical nature (e.g., polyvinyl alcohol, chitosans) are reported. The proof-of-concept for the use of SPR technique in characterizing protein-nanoparticle interactions of surface-immobilized proteins (immunoglobulin G and bovine serum albumin, both involved in the formation of the corona) subjected to flowing SLN is demonstrated for non-chitosan-coated nanoparticles. All assayed nanosystems show more preference for IgG than for BSA, such preference being more pronounced in the case of polyvinyl-alcohol-coated SLN.Facultad de Ciencias ExactasCentro de Investigación y Desarrollo en Fermentaciones IndustrialesInstituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Sleep deprivation causes memory deficits by negatively impacting neuronal connectivity in hippocampal area CA1

Brief periods of sleep loss have long-lasting consequences such as impaired memory consolidation. Structural changes in synaptic connectivity have been proposed as a substrate of memory storage. Here, we examine the impact of brief periods of sleep deprivation on dendritic structure. In mice, we find that five hours of sleep deprivation decreases dendritic spine numbers selectively in hippocampal area CA1 and increased activity of the filamentous actin severing protein cofilin. Recovery sleep normalizes these structural alterations. Suppression of cofilin function prevents spine loss, deficits in hippocampal synaptic plasticity, and impairments in long-term memory caused by sleep deprivation. The elevated cofilin activity is caused by cAMP-degrading phosphodiesterase-4A5 (PDE4A5), which hampers cAMP-PKA-LIMK signaling. Attenuating PDE4A5 function prevents changes in cAMP-PKA-LIMK-cofilin signaling and cognitive deficits associated with sleep deprivation. Our work demonstrates the necessity of an intact cAMP-PDE4-PKA-LIMK-cofilin activation-signaling pathway for sleep deprivation-induced memory disruption and reduction in hippocampal spine density