442 research outputs found
Potencial hidráulico del Ecuador
Cabe mencionar que el presente trabajo que versa sobre el Potencial Hidráulico del Ecuador, constituye por su propio nombre algo muy ambicioso ya que al mencionar el agua sabemos que éste elemento líquido vital es de gran importancia en el convivir de la humanidad. El aire, el agua, y la tierra son elementos indispensables para la existencia de los seres vivos en nuestro continente. Al hacer referencia de los elementos constitutivos de la tierra, y en mi caso específico sobre lo que tiene relación al agua, vale la pena clasificar a esta bajo parámetros tanto por su origen, calidad, usos, etc. Al hacer referencia de los elementos constitutivos de Ia tierra, y en mi caso específico sobre lo que tiene relación al agua, vale la pena clasificar a ésta bajo parámetros tanto por su origen, calidad, usos, etc. En el País existen muchos recursos hidráulicos, los mismos que por falta de un buen uso así como un adecuado aprovechamiento técnico han sido factor negativo en su mayor parte. Con el aprovechamiento técnico racional ésta fuente inagotable de recursos hidráulicos constituyen Verdaderos potenciales de riqueza o sea, factor predominante de desarrollo tanto para la agricultura como para la energía eléctrica. Al mismo tiempo puedo decir que algunas cuencas y ríos han sido optimas de uso múltiple como para represar agua para riego y para generar fuerza eléctrica; estos proyectos son los que en realidad interesan al país y en este caso específico al trabajo de investigación individual
Gene networks driving bovine milk fat synthesis during the lactation cycle
<p>Abstract</p> <p>Background</p> <p>The molecular events associated with regulation of milk fat synthesis in the bovine mammary gland remain largely unknown. Our objective was to study mammary tissue mRNA expression via quantitative PCR of 45 genes associated with lipid synthesis (triacylglycerol and phospholipids) and secretion from the late pre-partum/non-lactating period through the end of subsequent lactation. mRNA expression was coupled with milk fatty acid (FA) composition and calculated indexes of FA desaturation and <it>de novo </it>synthesis by the mammary gland.</p> <p>Results</p> <p>Marked up-regulation and/or % relative mRNA abundance during lactation were observed for genes associated with mammary FA uptake from blood (<it>LPL</it>, <it>CD36</it>), intracellular FA trafficking (<it>FABP3</it>), long-chain (<it>ACSL1</it>) and short-chain (<it>ACSS2</it>) intracellular FA activation, <it>de novo </it>FA synthesis (<it>ACACA</it>, <it>FASN</it>), desaturation (<it>SCD</it>, <it>FADS1</it>), triacylglycerol synthesis (<it>AGPAT6</it>, <it>GPAM</it>, <it>LPIN1</it>), lipid droplet formation (<it>BTN1A1</it>, <it>XDH</it>), ketone body utilization (<it>BDH1</it>), and transcription regulation (<it>INSIG1</it>, <it>PPARG</it>, <it>PPARGC1A</it>). Change in <it>SREBF1 </it>mRNA expression during lactation, thought to be central for milk fat synthesis regulation, was ≤2-fold in magnitude, while expression of <it>INSIG1</it>, which negatively regulates SREBP activation, was >12-fold and had a parallel pattern of expression to <it>PPARGC1A</it>. Genes involved in phospholipid synthesis had moderate up-regulation in expression and % relative mRNA abundance. The mRNA abundance and up-regulation in expression of <it>ABCG2 </it>during lactation was markedly high, suggesting a biological role of this gene in milk synthesis/secretion. Weak correlations were observed between both milk FA composition and desaturase indexes (i.e., apparent SCD activity) with mRNA expression pattern of genes measured.</p> <p>Conclusion</p> <p>A network of genes participates in coordinating milk fat synthesis and secretion. Results challenge the proposal that <it>SREBF1 </it>is central for milk fat synthesis regulation and highlight a pivotal role for a concerted action among <it>PPARG</it>, <it>PPARGC1A</it>, and <it>INSIG1</it>. Expression of <it>SCD</it>, the most abundant gene measured, appears to be key during milk fat synthesis. The lack of correlation between gene expression and calculated desaturase indexes does not support their use to infer mRNA expression or enzyme activity (e.g., <it>SCD</it>). Longitudinal mRNA expression allowed development of transcriptional regulation networks and an updated model of milk fat synthesis regulation.</p
Gene Networks Driving Bovine Mammary Protein Synthesis During the Lactation Cycle
A crucial role for both insulin and mTOR in the regulation of milk protein synthesis is emerging. Bovine mammary biopsies harvested during late-pregnancy through end of subsequent lactation were used to evaluate via quantitative PCR the expression of 44 genes involved in pathways of insulin, mTOR, AMPK, and Jak2-Stat5 signalling and also glucose and amino acid (AA) transporters. We observed an increased expression during lactation of ELF5, AA and glucose transporters, insulin signaling pathway components, MAPK14, FRAP1, EIF4EBP2, GSK3A and TSC1 among mTOR signaling-related genes. Among ribosomal components RPL22 was down-regulated. The overall data support a central role of AA and glucose transporters and insulin signaling through mTOR for the regulation of protein synthesis in bovine mammary gland. Furthermore, the existence of translational competition favoring the translation of milk protein transcripts was inferred from the combined dataset
Milk Protein Synthesis in the Lactating Mammary Gland: Insights from Transcriptomics Analyses
Expression of NGF, BDNF and their receptors in subcutaneous adipose tissue of lactating cows
Currently, there are no reports of neurotrophins in adipose tissue of cows. The distribution of nerve growth factor
(NGF), brain-derived neurotrophic factor (BDNF) and their high-affinity tyrosine kinase receptors TrkA and TrkB,
was investigated by immunohistochemical method in the subcutaneous adipose tissue of cow at mid-lactation.
Results revealed the localization of NGF and BDNF along the plasma membrane and cytoplasm of adipocytes.
Neurotrophin receptors TrkA and TrkB showedmoderate and strong positive staining in adipocytes, respectively.
The expression of NGF, BDNF, TRKB \u2014 but not of TRKA \u2014 was also confirmed at transcriptional level by RT-PCR
analyses.
Considering the involvement of BDNF on fat metabolism and of NGF on activation of the sympathetic response in
human and rodents, these neurotrophins could be related to lipogenesis and lipolysis occurring during lactation in
cows. The local production of these neurotrophins supports their potential paracrine function for the regulation of
adipocyte activity and deserve further investigations
Short communication: Endoplasmic reticulum stress gene network expression in bovine mammary tissue during the lactation cycle.
Abstract The endoplasmic reticulum (ER) has a crucial role in cellular metabolism. Recent studies in nonruminants discovered that components of the ER stress pathway, induced during the unfolded protein response, play critical roles in regulating lipogenesis. The bovine mammary gland faces extreme metabolic stress at the onset of lactation due primarily to the increase in flux through pathways associated with milk fat and protein synthesis. Our objective was to study, via quantitative real-time PCR, the expression of the ER stress pathway components P58IPK , PERK , XBP1 , ATF4 , ATF3 , ATF6 , CHOP , MBTPS1 , GRP94 , and BiP in mammary tissue (n=7 cows × 5 time points) collected at −15, 1, 15, 60, and 240 d relative to parturition. Expression of P58IPK and ATF4 increased to a peak at d 60, followed by a decrease by d 240 postpartum. Despite the decrease in expression by 240 d, P58IPK remained higher than prepartal levels (d −15). Expression patterns of ATF3 and CHOP were similar and peaked at d 15, followed by a decrease through d 240, at which point CHOP expression was still greater than prepartal levels. The sharp increase in milk production postpartum (d 15) as well as apoptosis during late lactation (240 d) may have induced a pseudo unfolded protein response state. This is supported by the similar expression patterns of P58IPK and PERK . In the context of lactation, however, transcriptional changes in the ER stress pathway at different stages of the lactation cycle are a normal aspect of the tissue's adaptation to the changing physiological state
Entrenamiento de la potencia en corredores de 100 mts planos
pdfEl autor de la presente investigación por tener más de 30 años como entrenador pudo observar la deficiencia con relación a la carencia de potencia de los seleccionados, puede enunciar el siguiente problema ¿Cómo va a mejorar el entrenamiento de la Potenciación, en la carrera de 100m planos en los atletas de la Universidad de Guayaquil?, para esta problemática se ha confeccionado una gama de ejercicios aplicando el método integral, el cual mejorara la potencia en los atletas y por ende su marca y tiempo. El trabajo investigativo se lo ha realizado mediante el método descriptivo detallando cada uno de los pasos a seguir, es secuencial explicativo descriptivo experimental. Los resultados de la investigación fueron significativos ya que los atletas mejoraron en el grupo femenino (6 damas) teniendo un promedio de tiempo de 8,63 segundos en el pre test, mientras que en el post-test se mejoró con un promedio de 7,86 lo que equivale a un 91%. En lo que se relaciona a los resultados del grupo masculino (11 varones) en el pre-test se obtuvo 8,02 segundos como promedio, mientras que en el post-test se obtuvo 7,21 segundos dando como un mejoramiento en porcentaje de 90,56%. El ejercicio expuesto en el presente trabajo investigativo servirá para que los entrenadores de atletismo en lo que se refiere a la potenciación aplicada a los deportistas de la prueba de 100 metros planos mejoren dentro de su rendimiento deportivo a sus
deportistas y puedan obtener excelentes resultados dentro de su marcas y tiempos.The author of the present investigation to have more than 30 years like trainer could
observe the deficiency with relationship to the lack of power of the selected ones, can it enunciate the following problem How it will improve the training of the Potentiation, in the career of 100m planes in the athletes of the University of Guayaquil? for this problem a range of exercises has been made applying the integral method, which improved the power in the athletes and for ende its mark and time. The investigative work has carried out it to him by means of the descriptive method detailing each one of the steps to continue, it is sequential explanatory descriptive experimental. The results of the investigation were significant since the athletes improved in the feminine group (6 ladies) having an average of time of 8,63 seconds in the pre-test, while in the post-test he/she improved with an average of 7,86 what is equal to 91%. In what is related to the results of the masculine group (11 males) in the pre-test it was obtained 8,02 seconds like average, while in the post-test it was obtained 7,21 seconds giving as an improvement in percentage of 90,56%. The exposed exercises presently investigative work will serve so that the athletics trainers in what refers to the applied potentiation to the sportsmen of the test of 100 plane meters improve inside its sport yield to their sportsmen and they can obtain excellent results in its marks and times
Differences in liver functionality indexes in peripartal dairy cows fed rumen-protected methionine or choline are associated with performance, oxidative stress status, and plasma amino acid profiles
The liver functionality index (LFI) represents an assessment of transition cow metabolic health by measuring changes in biomarkers associated with liver plasma protein synthesis (albumin), lipoprotein synthesis (cholesterol), and heme catabolism (bilirubin). The present analysis was conducted to determine the role of peripartal rumen-protected Met or choline (CHOL) supplementation on LFI groupings, and to assess relationships with performance, inflammation, oxidative stress status, and plasma AA profiles. A cohort of 40 multiparous Holstein cows that were part of a randomized complete block design with 2 × 2 factorial arrangement of Met (Smartamine M, Adisseo NA, Alpharetta, GA) and CHOL (ReaShure, Balchem Inc., New Hampton, NY) level (with or without) were used. From -21 d to calving, cows received the same close-up diet and were assigned randomly to each treatment. From calving to 30 d, cows were on the same postpartal diet and continued to receive the same treatments until 30 d. Addition of Met was adjusted daily at 0.08% dry matter of diet and CHOL was fed at 60 g/cow per day. Liver (-10, 7, 20, and 30 d) and blood (-10, 4, 8, 20, and 30 d) samples were harvested for biomarker analyses. Cows were ranked retrospectively and assigned to low (LLFI, LFI0) and high (HLFI, LFI0) LFI groups regardless of Met or CHOL supplementation. Compared with cows in LLFI, close-up and lactation DMI, milk yield, milk fat yield, and milk protein yield were greater in HLFI cows. As expected, cows in LLFI had lower plasma cholesterol and albumin but greater bilirubin concentrations around parturition. Plasma haptoglobin concentration was also lower in HLFI cows, but plasma paraoxonase and hepatic total and reduced hepatic glutathione concentrations were greater. Although higher concentrations of His, Met, and Trp, as well as a tendency for greater Ile, were observed in HLFI cows, overall essential AA concentrations did not differ with LFI status. In contrast, overall concentrations of nonessential AA were greater in HLFI cows due to greater circulating concentrations of Ala, Asn, Gln, Pro, and Ser. Similarly, overall concentrations of total AA and total sulfur-containing compounds were greater in cows with HLFI. Feeding Met compared with CHOL led to a tendency for more cows classified as HLFI. Overall, results support the broader application of the LFI in the management of transition cows. In that context, the fact that precalving concentrations of compounds such as reduced glutathione, total sulfur-containing compounds, Met, Tau, and homocysteine differed between HLFI and LLFI independent of Met or CHOL feeding also underscores their potential for monitoring cows that might be at a greater risk of developing health problems after calving. Further studies on the applicability of these biomarkers to monitor transition success appears warranted
Estudio y propuesta de reformas a la ley de arbitraje y mediación
Este trabajo presenta una propuesta de reforma a la Ley de Arbitraje y Mediación de Ecuador
orientada a mejorar los procesos de las áreas de administración de justicia tanto de
Mediación como de Arbitraje. Busca sugerir cambios que procuren la realización de la meta
del arbitraje y mediación, esto es, que se obtenga justicia de manera eficiente, principalmente
buscando evitar alargar conflictos y exposición a la opción judicial, ampliando la esfera de
la legalidad de los procesos y la disponibilidad de Mediadores. En ese sentido, busca
observar la Ley desde el punto de vista del ejercicio profesional y la experiencia en el libre
ejercicio del día a día.
No es, entonces, un trabajo basado en teorías de autores de la materia sino más bien un
trabajo de propuestas emanadas de aquellas vivencias en la defensa de causas. Las
propuestas consisten en indicar las desventajas que se encuentre en el artículo que se propone
modificar versus la codificación que se sugiere; así también se propondrá unos artículos que
no existen
The effect of calving in the summer on the hepatic transcriptome of Holstein cows during the peripartal period
The liver is the main metabolic organ coordinating the adaptations that take place during the peripartal period of dairy cows. A successful transition into lactation, rather than management practices alone, depends on environmental factors such as temperature, season of parturition, and photoperiod. Therefore, we analyzed the effect of calving season on the hepatic transcriptome of dairy cows during the transition period. A total of 12 Holstein dairy cows were assigned into 2 groups based on calving season (6 cows March-April, spring; 6 cows June-July, summer, SU). The RNA was extracted from liver samples obtained at -30, 3, and 35 DIM via percutaneous biopsy and hybridized to the Agilent 44K Bovine (V2) Gene Expression Microarray (Agilent Technologies Inc., Santa Clara, CA). A quantitative PCR on 22 target genes was performed to verify and expand the analyses. A total of 4,307 differentially expressed genes were detected (false discovery rate ≤0.05) in SU compared with spring. Furthermore, 73 unique differentially expressed genes were detected in SU compared with spring cows after applying a fold-change threshold ≥3 and ≤-3. For Kyoto Encyclopedia of Genes and Genomes pathways analysis of differentially expressed genes, we used the dynamic impact approach. Ingenuity Pathway Analysis software was used to analyze upstream transcription regulators and perform gene network analysis. Among metabolic pathways, energy metabolism from lipids, carbohydrates, and amino acids was strongly affected by calving in SU, with a reduced level of fatty acid synthesis, oxidation, re-esterification, and synthesis of lipoproteins, leading to hepatic lipidosis. Glycan-synthesis was downregulated in SU cows probably as a mechanism to counteract the progression of this lipidosis. In contrast, calving in the SU resulted in upregulation of gluconeogenesis but also greater use of glucose as an energy source. Among nonmetabolic pathways, the heat-shock response was obviously activated in SU cows but was also associated with inflammatory and intracellular stress response. Furthermore, data support a recent finding that cows experience endoplasmic reticulum stress around parturition. Transcription regulator analysis revealed how metabolic changes are related to important regulatory mechanisms, including epigenetic modification. The holistic analyses of the liver transcriptome response to calving in the summer at high environmental temperatures underscore how transition cows should be carefully managed during this period, as they experience alterations in liver energy metabolism and inflammatory state increasing susceptibility to health disorders in early postpartum
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