Finite-thrust transfer in the two and three body problems Final report

Computer program for optimal finite thrust transfer between two orbit

Bioderived dyes-mediated vat photopolymerization 3D printing of chitosan hydrogels for tissue engineering

The importance of 3D printable hydrogels is constantly increasing in the field of tissue engineering, due to their characteristic structure and similarity with the human body extracellular matrix (ECM). Herein, Quinizarin-based bioderived photoactive dyes were employed for the 3D printing of methacrylated chitosan by vat pho-topolymerization (VPP). Dyes are commonly needed in VPP to obtain good resolution avoiding the light scattering in the vat, here the bioderived molecules had further utility granting the printability with good resolution while acting both as photosensitizers and fillers/crosslinkers. Defined and detailed architectures in the range of millimetres were obtained with low printing times showing for the first time the possibility to obtain all-chitosan 3D structures with suspended features by Digital Light Processing (DLP), which is a form of vat photopolymerization; such a result is not achievable without the quinizarin-derived dyes. The same structures were achieved with an opti-mized concentration of poly(ethylene glycol) diacrylate, as a comparison, enhancing the resolution. For all the formulations, the important feature to obtain the gel printability (considering reactiveness, viscosity, shear thinning behaviour, mechanical properties and stability) were evaluated. The hydrogels mechanical character-ization and swelling properties were also tested and reported. Lastly, the possible application in tissue engi-neering was also evaluated through cell proliferation analysis over samples, including metabolic activity and DNA contempt assays. The use of such bioderived photoactive molecules that simultaneously act as photosensitizer enhancing the ink reactivity, as dye improving the definition of the final structures and as filler/crosslinker increasing the me-chanical stability, could represent a valuable route for the DLP printing of soft hydrogels

Lecturas de política monetaria y financiera

1 archivo PDF (487 páginas)Conjunto de trabajos de investigadores especializados en teoría monetaria y financiera, que presentan un análisis teórico y empírico de los cambios de la economía mexicana, propuestas y críticas tanto de los procesos mismos cómo de las políticas con que enfrentan las autoridades monetarias nacionales el reto que implica la mayor integración del sistema mexicano al internacional. Las investigaciones se agrupan en seis secciones temáticas: Política monetaria y cambiaria; Influencia de los flujos internacionales de capital; La política monetaria y sus relaciones con la inflación; Sector financiero, crisis y política económica; Sector bursátil y Marco Legal

Transcript profiling of candidate genes in testis of pigs exhibiting large differences in androstenone levels

<p>Abstract</p> <p>Background</p> <p>Boar taint is an unpleasant odor and flavor of the meat and occurs in a high proportion of uncastrated male pigs. Androstenone, a steroid produced in testis and acting as a sex pheromone regulating reproductive function in female pigs, is one of the main compounds responsible for boar taint. The primary goal of the present investigation was to determine the differential gene expression of selected candidate genes related to levels of androstenone in pigs.</p> <p>Results</p> <p>Altogether 2560 boars from the Norwegian Landrace and Duroc populations were included in this study. Testicle samples from the 192 boars with most extreme high or low levels of androstenone in fat were used for RNA extraction, and 15 candidate genes were selected and analyzed by real-competitive PCR analysis. The genes Cytochrome P450 c17 (<it>CYP17A1</it>), Steroidogenic acute regulatory protein (<it>STAR</it>), Aldo-keto reductase family 1 member C4 (<it>AKR1C4</it>), Short-chain dehydrogenase/reductase family member 4 (<it>DHRS4</it>), Ferritin light polypeptide (<it>FTL</it>), Sulfotransferase family 2A, dehydroepiandrosterone-preferring member 1 (<it>SULT2A1</it>), Cytochrome P450 subfamily XIA polypeptide 1 (<it>CYP11A1</it>), Cytochrome b5 (<it>CYB5A</it>), and 17-beta-Hydroxysteroid dehydrogenase IV (<it>HSD17B4</it>) were all found to be significantly (P < 0.05) up-regulated in high androstenone boars in both Duroc and Landrace. Furthermore, Cytochrome P450 c19A2 (<it>CYP19A2</it>) was down-regulated and progesterone receptor membrane component 1 (<it>PGRMC1</it>) was up-regulated in high-androstenone Duroc boars only, while <it>CYP21 </it>was significantly down-regulated (2.5) in high-androstenone Landrace only. The genes Nuclear Receptor co-activator 4 (<it>NCOA4</it>), Sphingomyrlin phosphodiesterase 1 (<it>SMPD1</it>) and 3β-hydroxysteroid dehydrogenase (<it>HSD3B</it>) were not significantly differentially expressed in any breeds. Additionally, association studies were performed for the genes with one or more detected SNPs. Association between SNP and androstenone level was observed in <it>CYB5A </it>only, suggesting cis-regulation of the differential transcription in this gene.</p> <p>Conclusion</p> <p>A large pig material of highly extreme androstenone levels is investigated. The current study contributes to the knowledge about which genes that is differentially expressed regard to the levels of androstenone in pigs. Results in this paper suggest that several genes are important in the regulation of androstenone level in boars and warrant further evaluation of the above mentioned candidate genes, including analyses in different breeds, identification of causal mutations and possible gene interactions.</p

Characterization of PTZ-Induced Seizure Susceptibility in a Down Syndrome Mouse Model That Overexpresses CSTB

Down syndrome (DS) is a complex genetic syndrome characterized by intellectual disability, dysmorphism and variable additional physiological traits. Current research progress has begun to decipher the neural mechanisms underlying cognitive impairment, leading to new therapeutic perspectives. Pentylenetetrazol (PTZ) has recently been found to have positive effects on learning and memory capacities of a DS mouse model and is foreseen to treat DS patients. But PTZ is also known to be a convulsant drug at higher dose and DS persons are more prone to epileptic seizures than the general population. This raises concerns over what long-term effects of treatment might be in the DS population. The cause of increased propensity for epilepsy in the DS population and which Hsa21 gene(s) are implicated remain unknown. Among Hsa21 candidate genes in epilepsy, CSTB, coding for the cystein protease inhibitor cystatin B, is involved in progressive myoclonus epilepsy and ataxia in both mice and human. Thus we aim to evaluate the effect of an increase in Cstb gene dosage on spontaneous epileptic activity and susceptibility to PTZ-induced seizure. To this end we generated a new mouse model trisomic for Cstb by homologous recombination. We verified that increasing copy number of Cstb from Trisomy (Ts) to Tetrasomy (Tt) was driving overexpression of the gene in the brain, we checked transgenic animals for presence of locomotor activity and electroencephalogram (EEG) abnormalities characteristic of myoclonic epilepsy and we tested if those animals were prone to PTZ-induced seizure. Overall, the results of the analysis shows that an increase in Cstb does not induce any spontaneous epileptic activity and neither increase or decrease the propensity of Ts and Tt mice to myoclonic seizures suggesting that Ctsb dosage should not interfere with PTZ-treatment

Differential Regulation of the Variations Induced by Environmental Richness in Adult Neurogenesis as a Function of Time: A Dual Birthdating Analysis

Adult hippocampal neurogenesis (AHN) augments after environmental enrichment (EE) and it has been related to some of the anxiolytic, antidepressant and neuroprotective effects of EE. Indeed, it has been suggested that EE specifically modulates hippocampal neurogenic cell populations over the course of time. Here we have used dual-birthdating to study two subpopulations of newborn neuron in mice (Mus musculus): those born at the beginning and at the end of enrichment. In this way, we demonstrate that while short-term cell survival is upregulated after an initial 1 week period of enrichment in 2 month old female mice, after long-term enrichment (2 months) neither cell proliferation nor the survival of the younger newly born cell populations are distinguishable from that observed in non-enriched control mice. In addition, we show that the survival of older newborn neurons alone (i.e. those born at the beginning of the enrichment) is higher than in controls, due to the significantly lower levels of cell death. Indeed, these parameters are rapidly adjusted to the sudden cessation of the EE conditions. These findings suggest both an early selective, long-lasting effect of EE on the neurons born in the initial stages of enrichment, and a quick response when the environment again becomes impoverished. Therefore, EE induces differential effects on distinct subpopulations of newborn neurons depending on the age of the immature cells and on the duration of the EE itself. The interaction of these two parameters constitutes a new, specific regulation of these neurogenic populations that might account for the long-term enrichment's behavioral effects

A method to decipher pleiotropy by detecting underlying heterogeneity driven by hidden subgroups applied to autoimmune and neuropsychiatric diseases

There is growing evidence of shared risk alleles between complex traits (pleiotropy), including autoimmune and neuropsychiatric diseases. This might be due to sharing between all individuals (whole-group pleiotropy), or a subset of individuals within a genetically heterogeneous cohort (subgroup heterogeneity). BUHMBOX is a well-powered statistic distinguishing between these two situations using genotype data. We observed a shared genetic basis between 11 autoimmune diseases and type 1 diabetes (T1D, p0.2, 6,670 T1D cases and 7,279 RA cases). Genetic sharing between seronegative and seropostive RA (p<10−9) had significant evidence of subgroup heterogeneity, suggesting a subgroup of seropositive-like cases within seronegative cases (pBUHMBOX=0.008, 2,406 seronegative RA cases). We also observed a shared genetic basis between major depressive disorder (MDD) and schizophrenia (p<10−4) that was not explained by subgroup heterogeneity (pBUHMBOX=0.28 in 9,238 MDD cases)