Reseña de las teorías sobre aglomeraciones económicas, a través del tiempo

The present work is part of a larger one whose general objective is to highlight the importance of the impacts that are generated not only in the economic spheres, but also in the socio-cultural, political, technological conditions, innovations, relationships to and from institutions and support services, paying special attention to how the new conceptions of globalized markets impact the way links and clusters are created For the above, it starts from knowing the basic concepts of the regional economics schools that have given way to theories about the agglomeration of companies and their impacts. Knowing a little about agglomeration economies, Industrial Districts, Productive Chains and ClustersEl presente trabajo forma parte de uno más extenso cuyo objetivo general es destacar la importancia de los impactos que se generan no solo en los ámbitos económicos, sino también, en las condiciones socio - culturales, políticas, tecnológicas, las innovaciones, relaciones hacia y desde las instituciones y los servicios de soporte, prestando especial énfasis a como las nuevas concepciones de mercados globalizados impacta en la forma de crear eslabones y clústeres Para lo anterior se parte de conocer los conceptos básicos de las escuelas de la economía regional que han dado paso a teorías sobre la aglomeración de las empresas y sus impactos. Conociendo un poco las economías de aglomeración, los Distritos Industriales, los Encadenamientos Productivos y los Clústeres

Desarrollo de un banco experimental de un motor de combustión interna diesel

Con el propósito de llegar a las futuras generaciones en el campo de la ingeniería electromecánica, una herramienta en donde puedan consolidar el aprendizaje de esta disciplina, se gestiona a través, de la donación de un motor de combustión interna diésel, el cual, este acondicionado para realizar los procedimientos correspondientes a la evaluación de componentes, sistemas, mantenimiento correctivo, puesta a punto, encendido y monitoreo en operación; todo esto debidamente documentado, con fines de complementación formativa con base en prácticas experimentales dirigidas a la población estudiantil de dicho pregrado. Con este proceso pretendemos, además, brindar alternativas de aprendizaje mediante el reconocimiento físico de la obtención de trabajo a través de una máquina térmica en funcionamiento. Finalmente, consideramos importante, que a partir de este proyecto, la comunidad de la facultad de ingenierías, desarrollen habilidades que les permitan profundizar en el campo de la investigación y la innovación, debido a las opciones que a partir de este banco puedan derivarse en pro del perfeccionamiento del mismo.Ingeniero Electromecánicopregrad

Presencia de coliformes fecales y totales en el Isognomon alatus en la laguna de Tampamachoco Veracruz

La Laguna de Tampamachoco, Veracruz tiene gran importancia económica y ecológica ya que es una de las más ricas en especies de peces, moluscos, crustáceos y bivalvos. Los bivalvos desempeñan un papel importante, debido a sus hábitos pueden actuar como filtradores biológicos, así como bioindicadores. La cavidad intervalvar y los tejidos acumulan toxinas y contaminantes, entre los más comunes son las bacterias de coliformes. Para este estudio, se realizaron 3 muestreos durante un periodo anual en seis sitios de muestreo, con el objetivo de determinar la calidad bacteriológica de Isognomon alatus en la Laguna Tampachoco. Para este estudio se usaron bacterias coliformes fecales y totales como indicadores de contaminación, los cuales fueron determinados con el método de tubos múltiples de fermentación (Número Más Probable NMP) con series de cinco tubos. La mayor concentración de coliformes totales fue de540 NMP/100g para el mes de octubre del 2012 y 460 NMP/100g en enero del 2012 en los sitios Restinga Grande y Punta Rica. Mientras para coliformes fecales todos los valores registrados estuvieron por debajo del Límite Máximo Permitido de 230 NMP/100g por la NOM-242-SSA1-2002. Los resultados mostraron que la cantidad de coliformes fecales presentes en I. alatus y de acuerdo a la normatividad, indicó que no existe contaminación alguna de acuerdo a lo establecido

Benzodiazepines and Related Drugs as a Risk Factor in Alzheimer's Disease Dementia.

Benzodiazepines (BZDs) and Z-drugs are compounds widely prescribed in medical practice due to their anxiolytic, hypnotic, and muscle relaxant properties. Yet, their chronic use is associated with cases of abuse, dependence, and relapse in many patients. Furthermore, elderly people are susceptible to alterations in pharmacodynamics, pharmacokinetics as well as to drug interaction due to polypharmacy. These situations increase the risk for the appearance of cognitive affectations and the development of pathologies like Alzheimer's disease (AD). In the present work, there is a summary of some clinical studies that have evaluated the effect of BZDs and Z-drugs in the adult population with and without AD, focusing on the relationship between their use and the loss of cognitive function. Additionally, there is an assessment of preclinical studies focused on finding molecular proof on the pathways by which these drugs could be involved in AD pathogenesis. Moreover, available data (1990-2019) on BZD and Z-drug use among elderly patients, with and without AD, was compiled in this work. Finally, the relationship between the use of BZD and Z-drugs for the treatment of insomnia and the appearance of AD biomarkers was analyzed. Results pointed to a vicious circle that would worsen the condition of patients over time. Likewise, it put into relevance the need for close monitoring of those patients using BZDs that also suffer from AD. Consequently, future studies should focus on optimizing strategies for insomnia treatment in the elderly by using other substances like melatonin agonists, which is described to have a much more significant safety profile

A metabolic perspective of late onset Alzheimer's disease

After decades of research, the molecular neuropathology of Alzheimer's disease (AD) is still one of the hot topics in biomedical sciences. Some studies suggest that soluble amyloid β (Aβ) oligomers act as causative agents in the development of AD and could be initiators of its complex neurodegenerative cascade. On the other hand, there is also evidence pointing to Aβ oligomers as mere aggravators, with an arguable role in the origin of the disease. In this line of research, the relative contribution of soluble Aβ oligomers to neuronal damage associated with metabolic disorders such as Type 2 Diabetes Mellitus (T2DM) and obesity is being actively investigated. Some authors have proposed the endoplasmic reticulum (ER) stress and the induction of the unfolded protein response (UPR) as important mechanisms leading to an increase in Aβ production and the activation of neuroinflammatory processes. Following this line of thought, these mechanisms could also cause cognitive impairment. The present review summarizes the current understanding on the neuropathological role of Aβ associated with metabolic alterations induced by an obesogenic high fat diet (HFD) intake. It is believed that the combination of these two elements has a synergic effect, leading to the impairement of ER and mitochondrial functions, glial reactivity status alteration and inhibition of insulin receptor (IR) signalling. All these metabolic alterations would favour neuronal malfunction and, eventually, neuronal death by apoptosis, hence causing cognitive impairment and laying the foundations for late-onset AD (LOAD). Moreover, since drugs enhancing the activation of cerebral insulin pathway can constitute a suitable strategy for the prevention of AD, we also discuss the scope of therapeutic approaches such as intranasal administration of insulin in clinical trials with AD patients

Strategies against β-amyloid protein as therapeutics in Alzheimer's disease

Podeu consultar el llibre complet a: http://hdl.handle.net/2445/12071

The Ethyl Acetate Extract of Leaves of Ugni molinae Turcz. Improves Neuropathological Hallmarks of Alzheimer's Disease in Female APPswe/PS1dE9 Mice Fed with a High Fat Diet

The most common type of dementia is Alzheimer's disease (AD), a progressive neurodegenerative disease characterized by impairment in cognitive performance in aged individuals. Currently, there is no effective pharmacological treatment that cures the disease due to the lack of knowledge on the actual mechanisms involved in its pathogenesis. In the last decades, the amyloidogenic hypothesis has been the most studied theory trying to explain the origin of AD, yet it does not address all the concerns relating to its development. In the present study, a possible new preclinical treatment of AD was evaluated using the ethyl acetate extract (EAE) of leaves of Ugni molinae Turcz. (synonym Myrtus ugni Molina Family Myrtacea). The effects were assessed on female transgenic mice from a preclinical model of familial AD (APPswe/PS1dE9) combined with a high fat diet. This preclinical model was selected due to the already available experimental and observational data proving the relationship between obesity, gender, metabolic stress, and cognitive dysfunction; related to characteristics of sporadic AD. According to chemical analyses, EAE would contain polyphenols such as tannins, flavonoid derivatives, and phenolic acids, as well as pentacyclic triterpenoids that exhibit neuroprotective, anti-inflammatory, and antioxidant effects. In addition, the treatment evidenced its capacity to prevent deterioration of memory capacity and reduction of progression speed of AD neuropathology

The Implication of the Brain Insulin Receptor in Late Onset Alzheimer's Disease Dementia

Alzheimer's disease (AD) is progressive neurodegenerative disorder characterized by brain accumulation of the amyloid β peptide (Aβ), which form senile plaques, neurofibrillary tangles (NFT) and, eventually, neurodegeneration and cognitive impairment. Interestingly, epidemiological studies have described a relationship between type 2 diabetes mellitus (T2DM) and this pathology, being one of the risk factors for the development of AD pathogenesis. Information as it is, it would point out that, impairment in insulin signalling and glucose metabolism, in central as well as peripheral systems, would be one of the reasons for the cognitive decline. Brain insulin resistance, also known as Type 3 diabetes, leads to the increase of Aβ production and TAU phosphorylation, mitochondrial dysfunction, oxidative stress, protein misfolding, and cognitive impairment, which are all hallmarks of AD. Moreover, given the complexity of interlocking mechanisms found in late onset AD (LOAD) pathogenesis, more data is being obtained. Recent evidence showed that Aβ42 generated in the brain would impact negatively on the hypothalamus, accelerating the 'peripheral' symptomatology of AD. In this situation, Aβ42 production would induce hypothalamic dysfunction that would favour peripheral hyperglycaemia due to down regulation of the liver insulin receptor. The objective of this review is to discuss the existing evidence supporting the concept that brain insulin resistance and altered glucose metabolism play an important role in pathogenesis of LOAD. Furthermore, we discuss AD treatment approaches targeting insulin signalling using anti-diabetic drugs and mTOR inhibitors

Construcción de cónicas y de curvas pedal

Durante el desarrollo del taller se presentarán varias construcciones de las cónicas utilizando el programa Cabri y se solucionarán problemas que utilicen estas construcciones o que empleen cónicas

Memantine for the treatment of dementia. A review on its current and future applications

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by the presence in the brain of extracellular amyloid-β protein (Aβ) and intracellular neurofibrillary tangles composed of hyperphosphorylated tau protein. The N-Methyl-D-aspartate receptors (NMDAR), ionotropic glutamate receptor, are essential for processes like learning and memory. An excessive activation of NMDARs has been associated with neuronal loss. The discovery of extrasynaptic NMDARs provided a rational and physiological explanation between physiological and excitotoxic actions of glutamate. Memantine (MEM), an antagonist of extrasynaptic NMDAR, is currently used for the treatment of AD jointly with acetylcholinesterase inhibitors. It has been demonstrated that MEM preferentially prevents the excessive continuous extrasynaptic NMDAR disease activation and therefore prevents neuronal cell death induced by excitotoxicity without disrupting physiological synaptic activity. The problem is that MEM has shown no clear positive effects in clinical applications while, in preclinical stages, had very promising results. The data in preclinical studies suggests that MEM has a positive impact on improving AD brain neuropathology, as well as in preventing Aβ production, aggregation, or downstream neurotoxic consequences, in part through the blockade of extrasynaptic NMDAR. Thus, the focus of this review is primarily to discuss the efficacy of MEM in preclinical models of AD, consider possible combinations of this drug with others, and then evaluate possible reasons for its lack of efficacy in clinical trials. Finally, applications in other pathologies are also considered