86 research outputs found
Modelling and PID Control of a Rotary Dryer
This paper describes the modelling and the PID control of a drying process. The plant uses a co-current rotary dryer to evaporate moisture of a waste product generated by olive-oil mills, called alpeorujo or two phase cake. The paper shows the development of a model based upon first principles combined with experimental results. A control strategy has been tested under simulation based on PID controllers for the main loops in this process
Cambios en la distribución y concentración del empleo femenino en la economía española, 1994-2004: ¿persiste la segregación en el empleo por razón de sexo?
Cálculo del contenido celular de carbono de cuatro taxones de diatomeas: biovolumen y espectrofotometría
Background. Phytoplankton biomass is an essential parameter in aquatic ecosystems; two of the most widely usedindicators for estimating phytoplankton biomass are chlorophyll-a (Chl-a) by spectrophotometry and biovolume (BV).Goals. To show how different results are when estimating phytoplankton biomass by means of the spectrophotometricand BV methods. Methods. Biomass by Chl-a and BV were estimated in four cultures of marine diatoms. For estimatingBV, we used live cells and acid Lugols solution fixed cells. Results. Biomass values were noticeably different: the BV forThalassiosira hispida and Skeletonema costatum underestimates ?41% of the biomass with respect to values obtained by spectrophotometry. In contrast, the BV for Pseudo-nitzschia sp. and Cylindrotheca closterium overestimates the biomass by 4% and 25%, respectively. In the case of estimated biovolume, the results indicate that fixer acid Lugols solution modified the size of the cell significantly in C. closterium and Pseudo-nitzschia sp. (p<0.05), but not for S. costatum and T. hispida (p>0.05). Two equations are provided for biomass calculation when studying live (pgC/cell = -1.5567 + 0.1428 (BV)) or acid Lugols solution fixed (pgC/cell = -5.0126 + 0.1644 (BV)) diatom cells. Conclusions. Although BV is useful, it can have drawbacks because it produces values above and below those estimated by spectrophotometry, in addition to the fact that acid Lugol´s solution modifies cell size. We would advise considering the available information based in Chl-a or carbon of different species.Antecedentes. La biomasa fitoplanctónica es un parámetro esencial en ecosistemas acuáticos; dos de los indicadoresindirectos más utilizados para su estimación son la clorofila-a (Cl-a) mediante espectrofotometría y el biovolumen (BV).Objetivos. Mostrar que tan distantes son las aproximaciones para calcular la biomasa fitoplanctónica utilizando los métodos de BV y espectrofotometría. Métodos. Se utilizaron cuatro taxones de diatomeas marinas en cultivo a los cuálesse les estimó la biomasa mediante Cl-a y BV, en el caso del BV se realizaron las estimaciones en células vivas y fijadascon Lugol ácido. Resultados. Los valores de biomasa obtenidos para Thalassiosira hispida y Skeletonema costatum sonmarcadamente diferentes, ya que el BV de células vivas subestima ?41% su biomasa con respecto al cálculo por espectrofotometría en ambas especies. En Pseudo-nitzschia sp. y Cylindrotheca closterium el BV sobreestima el 4% y 25% respectivamente la biomasa. El Lugol ácido modificó el tamaño de las células de manera significativa en C. closterium y Pseudo-nitzschia sp. (p<0.05), no siendo así con S. costatum y T. hispida (p>0.05). Se presentan dos ecuaciones para cuantificar la biomasa a partir de mediciones morfométricas de las células vivas (pgC/cel = -1.5567+ 0.1428 (BV)) y fijadas con Lugol ácido (pgC/cel = -5.0126 + 0.1644 (BV)). Conclusiones. Aunque el BV es útil, puede presentar inconvenientes ya que produce valores por arriba y por debajo de los estimados mediante espectrofotometría, además de que el Lugol ácido modifica el tamaño celular. Se recomienda considerar la información disponible basada en la Cl-a o carbono de diferentes especies
Productividad primaria bruta y respiración planctónica en el Parque Nacional Sistema Arrecifal Veracruzano
Planktonic gross primary productivity (GPP) and respiration (RP) were evaluated in the National Park Sistema Arrecifal Veracruzano (NPSAV) at the southwest of Gulf of Mexico from December 2008 to January 2012. Using these data we characterized the zone and identified the organic metabolism function of the ecosystem. The GPP values varied between 0-231 mgC m-3 h-1 and the RP values between 0-447 mgC m-3 h-1 . The north was different from south, with Playa Norte being the most productive site of the system. The north is influenced by anthropogenic activities such as the residual water treatment plant, whereas the south is influenced by the river plume of Jamapa during the rainy period. By the contrary Cabezo reef was the lowest productive; this site is the farest from the coast hence with no influence of Jamapa river plume. No differences were detected between sites associated to reefs and sites without reefs. The ratio GPP/RP indicated that the ecosystem is a source of CO2 most of the time, and in short periods of the year as a carbon sink.Se evaluó la productividad primaria bruta (PPB) y la respiración planctónica (RP) en el Parque Nacional Sistema Arrecifal Veracruzano (PNSAV), en el suroeste del Golfo de México durante diciembre de 2008 a enero de 2012. Con base en esto, se buscó caracterizar la zona e identificar la función del metabolismo orgánico del ecosistema. Los valores para la PPB oscilaron entre 0-231 mgC m-3 h-1 y para la RP entre 0-447 mgC m-3 h-1, La zona norte tuvo diferencia con la zona sur del área de estudio, siendo Playa Norte el sitio más productivo del sistema. La zona norte presentó una mayor influencia antropogénica, debido a una planta de tratamiento de aguas residuales, mientras que la zona sur está sometida a la influencia de la descarga del río Jamapa durante el período de lluvias. En contraste, el arrecife Cabezo fue el menos productivo; este sitio es el más lejano de la costa y por consiguiente sufre un menor efecto de la influencia del río Jamapa. No se encontraron diferencias entre los sitios asociados a arrecifes y sitios sin arrecifes. La razón PPB/RP, mostró que el ecosistema funciona la mayor parte del tiempo, como una fuente de CO2 y solo en periodos cortos del año, como un sumidero de carbono
Crtc1 activates a transcriptional program deregulated at early Alzheimer's disease-related stages
Cognitive decline is associated with gene expression changes in the brain, but the transcriptional mechanisms underlying memory impairments in cognitive disorders, such as Alzheimer's disease (AD), are largely unknown. Here, we aimed to elucidate relevant mechanisms responsible for transcriptional changes underlying early memory loss in AD by examining pathological, behavioral, and transcriptomic changes in control and mutant β-amyloid precursor protein (APPSw,Ind) transgenic mice during aging. Genome-wide transcriptome analysis using mouse microarrays revealed deregulation of a gene network related with neurotransmission, synaptic plasticity, and learning/memory in the hippocampus of APPSw,Ind mice after spatial memory training. Specifically, APPSw,Ind mice show changes on a cAMP-responsive element binding protein (CREB)-regulated transcriptional program dependent on the CREB-regulated transcription coactivator-1 (Crtc1). Interestingly, synaptic activity and spatial memory induces Crtc1 dephosphorylation (Ser151), nuclear translocation, and Crtc1-dependent transcription in the hippocampus, and these events are impaired in APPSw,Ind mice at early pathological and cognitive decline stages. CRTC1-dependent genes and CRTC1 levels are reduced in human hippocampus at intermediate Braak III/IV pathological stages. Importantly, adeno-associated viral-mediated Crtc1 overexpression in the hippocampus efficiently reverses Aβ-induced spatial learning and memory deficits by restoring a specific subset of Crtc1 target genes. Our results reveal a critical role of Crtc1-dependent transcription on spatial memory formation and provide the first evidence that targeting brain transcriptome reverses memory loss in AD
Laboratory and telescope demonstration of the TP3-WFS for the adaptive optics segment of AOLI
AOLI (Adaptive Optics Lucky Imager) is a state-of-art instrument that combines adaptive optics (AO) and lucky imaging (LI) with the objective of obtaining diffraction limited images in visible wavelength at mid- and big-size ground-based telescopes. The key innovation of AOLI is the development and use of the new TP3-WFS (Two Pupil Plane PositionsWavefront Sensor). The TP3-WFS, working in visible band, represents an advance over classical wavefront sensors such as the Shack-Hartmann WFS (SH-WFS) because it can theoretically use fainter natural reference stars, which would ultimately provide better sky coverages to AO instruments using this newer sensor. This paper describes the software, algorithms and procedures that enabled AOLI to become the first astronomical instrument performing real-time adaptive optics corrections
in a telescope with this new type of WFS, including the first control-related
results at the William Herschel Telescope (WHT)This work was supported by the Spanish Ministry of Economy under the projects AYA2011-29024, ESP2014-56869-C2-2-P, ESP2015-69020-C2-2-R and DPI2015-66458-C2-2-R, by project 15345/PI/10 from the Fundación Séneca, by the Spanish Ministry of Education under the grant FPU12/05573, by project ST/K002368/1 from the Science and Technology Facilities Council and by ERDF funds from the European Commission. The results presented in this paper are based on observations made with the William Herschel Telescope operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias. Special thanks go to Lara Monteagudo and Marcos Pellejero for their timely contributions
Crtc1 activates a transcriptional program deregulated at early Alzheimer's disease-related stages
Cognitive decline is associated with gene expression changes in the brain, but the transcriptional mechanisms underlying memory impairments in cognitive disorders, such as Alzheimer's disease (AD), are largely unknown. Here, we aimed to elucidate relevant mechanisms responsible for transcriptional changes underlying early memory loss in AD by examining pathological, behavioral, and transcriptomic changes in control and mutant β-amyloid precursor protein(APPSw,Ind) transgenic mice during aging. Genome-wide transcriptome analysis using mouse microarrays revealed deregulation of a gene network related with neurotransmission, synaptic plasticity, and learning/memory in the hippocampus of APPSw,Ind mice after spatial memory training. Specifically, APPSw,Ind mice show changes on a cAMP-responsive element binding protein(CREB)- regulated transcriptional program dependent on the CREB-regulated transcription coactivator-1 (Crtc1). Interestingly, synaptic activity and spatial memory induces Crtc1 dephosphorylation (Ser151), nuclear translocation, and Crtc1-dependent transcription in the hippocampus, and these events are impaired in APPSw,Ind mice at early pathological and cognitive decline stages. CRTC1-dependent genes and CRTC1 levels are reduced in human hippocampus at intermediate Braak III/IV pathological stages. Importantly, adeno-associated viral-mediated Crtc1 overexpression in the hippocampus efficiently reverses Aβ-induced spatial learning and memory deficits by restoring a specific subset of Crtc1 target genes. Our results reveal a critical role of Crtc1-dependent transcription on spatial memory formation and provide the first evidence that targeting brain transcriptome reverses memory loss in AD
Nurr1 protein is required for N-Methyl-d-aspartic Acid (NMDA) receptor-mediated neuronal survival
NMDA receptor (NMDAR) stimulation promotes neuronal survival during brain development. Cerebellar granule cells (CGCs) need NMDAR stimulation to survive and develop. These neurons differentiate and mature during its migration from the external granular layer to the internal granular layer, and lack of excitatory inputs triggers their apoptotic death. It is possible to mimic this process in vitro by culturing CGCs in low KCl concentrations (5 mm) in the presence or absence of NMDA. Using this experimental approach, we have obtained whole genome expression profiles after 3 and 8 h of NMDA addition to identify genes involved in NMDA-mediated survival of CGCs. One of the identified genes was Nurr1, a member of the orphan nuclear receptor subfamily Nr4a. Our results report a direct regulation of Nurr1 by CREB after NMDAR stimulation. ChIP assay confirmed CREB binding to Nurr1 promoter, whereas CREB shRNA blocked NMDA-mediated increase in Nurr1 expression. Moreover, we show that Nurr1 is important for NMDAR survival effect. We show that Nurr1 binds to Bdnf promoter IV and that silencing Nurr1 by shRNA leads to a decrease in brain-derived neurotrophic factor (BDNF) protein levels and a reduction of NMDA neuroprotective effect. Also, we report that Nurr1 and BDNF show a similar expression pattern during postnatal cerebellar development. Thus, we conclude that Nurr1 is a downstream target of CREB and that it is responsible for the NMDA-mediated increase in BDNF, which is necessary for the NMDA-mediated prosurvival effect on neurons
Transcriptional epigenetic regulation of Fkbp1/Pax9 genes is associated with impaired sensitivity to platinum treatment in ovarian cancer
Background: In an effort to contribute to overcoming the platinum resistance exhibited by most solid tumors, we performed an array of epigenetic approaches, integrating next-generation methodologies and public clinical data to identify new potential epi-biomarkers in ovarian cancer, which is considered the most devastating of gynecological malignancies. Methods: We cross-analyzed data from methylome assessments and restoration of gene expression through microarray expression in a panel of four paired cisplatin-sensitive/cisplatin-resistant ovarian cancer cell lines, along with publicly available clinical data from selected individuals representing the state of chemoresistance. We validated the methylation state and expression levels of candidate genes in each cellular phenotype through Sanger sequencing and reverse transcription polymerase chain reaction, respectively. We tested the biological role of selected targets using an ectopic expression plasmid assay in the sensitive/resistant tumor cell lines, assessing the cell viability in the transfected groups. Epigenetic features were also assessed in 189 primary samples obtained from ovarian tumors and controls. Results: We identified PAX9 and FKBP1B as potential candidate genes, which exhibited epigenetic patterns of expression regulation in the experimental approach. Re-establishment of FKBP1B expression in the resistant OVCAR3 phenotype in which this gene is hypermethylated and inhibited allowed it to achieve a degree of platinum sensitivity similar to the sensitive phenotype. The evaluation of these genes at a translational level revealed that PAX9 hypermethylation leads to a poorer prognosis in terms of overall survival. We also set a precedent for establishing a common epigenetic signature in which the validation of a single candidate, MEST, proved the accuracy of our computational pipelines. Conclusions: Epigenetic regulation of PAX9 and FKBP1B genes shows that methylation in non-promoter areas has the potential to control gene expression and thus biological consequences, such as the loss of platinum sensitivity. At the translational level, PAX9 behaves as a predictor of chemotherapy response to platinum in patients with ovarian cancer. This study revealed the importance of the transcript-specific study of each gene under potential epigenetic regulation, which would favor the identification of new markers capable of predicting each patient’s progression and therapeutic response.The study was financially supported by FIS (ISCIII) and ERDF/FSE funds
(PI15/00186, PI18/0050, and ERDF/FSE, A way to make Europe). The authors
gratefully acknowledge the Colombian Ministry for Science, Technology and
Innovation (MINCIENCIAS), Code 568-2012, for providing J.S. with partial funding
for this study
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