Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 240
Filtrar
1.
Actas Dermosifiliogr ; 113(4): 363-369, 2022 Apr.
Artículo en Inglés, Español | MEDLINE | ID: mdl-35623726

RESUMEN

BACKGROUND: The simplified psoriasis index (SPI) was developed in the United Kingdom to provide a simple summary measure for monitoring changes in psoriasis severity and associated psychosocial impact as well as for obtaining information about past disease behavior and treatment. Two complementary versions of the SPI allow for self-assessment by the patient or professional assessment by a doctor or nurse. Both versions have proven responsive to change, reliable, and interpretable, and to correlate well with assessment tools that are widely used in clinical trials - the Psoriasis Area and Severity Index and the Dermatology Quality of Life Index. The SPI has already been translated into several languages, including French, Brazilian Portuguese, Dutch, Arabic, and Thai. OBJECTIVE: To translate the professional and self-assessment versions of the SPI to Spanish and to field test the translations. METHOD: A medically qualified native Spanish speaker translated both versions of the SPI into Spanish. The Spanish translations were discussed by comparing them to blinded back translations into English undertaken by native English speakers; the Spanish texts were then revised in an iterative process involving the translators, 4 dermatologists, and 20 patients. The patients scored their own experience of psoriasis with the self-assessment version and commented on it. The process involved checking the conceptual accuracy of the translation, language-related differences, and subtle gradations of meaning in a process involving all translators and a panel of both Spanish- and English-speaking dermatologists, including a coauthor of the SPI. RESULTS: The final self-assessment and professional Spanish versions of the SPI are presented in this manuscript. CONCLUSIONS: Castilian Spanish translations of both versions of the SPI are now available for monitoring disease changes in Spanish-speaking patients with psoriasis under routine clinical care.


Asunto(s)
Lenguaje , Psoriasis , Humanos , Psoriasis/diagnóstico , Psoriasis/psicología , Calidad de Vida , Traducción , Traducciones
2.
Actas dermo-sifiliogr. (Ed. impr.) ; 113(4): 363-369, Abr. 2022. ilus, tab
Artículo en Español | IBECS | ID: ibc-206447

RESUMEN

Antecedentes: El índice de psoriasis simplificado (SPI) fue desarrollado en el Reino Unido con el fin de proveer un resumen métrico para monitorizar los cambios en la gravedad de la psoriasis (SPI-s) y su impacto social asociado (SPI-p), junto con su comportamiento y tratamiento previo (SPI-i). Existen dos versiones complementarias, una para profesionales de salud, incluidos médicos o enfermeras (proSPI) y otra para la autoevaluación de los pacientes (saSPI). Ambas versiones han demostrado tener una variabilidad al cambio, ser confiables y tener una buena correlación con los instrumentos más utilizados en los estudios clínicos, como el PASI y el DQLI. El SPI estaba ya disponible en versiones adaptadas del francés, portugués (Brasil), holandés, arábigo y tailandés. Objetivo: El objetivo del proyecto actual era producir y probar traducciones del proSPI y saSPI al español. Método: Un médico hispanohablante realizó la primera traducción de ambas versiones al español. Ambas versiones fueron comparadas con sus contratraducciones al inglés de hablantes nativos y luego fueron ajustadas en un proceso repetitivo de múltiples pasos conducidas por traductores, cuatro dermatólogos y veinte pacientes quienes colaboraron con la evaluación del saSPI. Se verificó cuidadosamente la exactitud conceptual al revisar las discrepancias lingüísticas o diferencias sutiles en los significados en un proceso que involucró a todos los traductores y panel incluyendo dermatólogos de habla inglesa como hispana incluyendo a un cocreador del SPI. Resultados: Se presentan en este manuscrito las versiones finales acordadas del SPI en español. Conclusiones: Las versiones del SPI en español (castellano) están ahora disponibles para monitorizar clínicamente a los pacientes con psoriasis (AU)


Background: The simplified psoriasis index (SPI) was developed in the United Kingdom to provide a simple summary measure for monitoring changes in psoriasis severity and associated psychosocial impact as well as for obtaining information about past disease behavior and treatment. Two complementary versions of the SPI allow for self-assessment by the patient or professional assessment by a doctor or nurse. Both versions have proven responsive to change, reliable, and interpretable, and to correlate well with assessment tools that are widely used in clinical trials — the Psoriasis Area and Severity Index and the Dermatology Quality of Life Index. The SPI has already been translated into several languages, including French, Brazilian Portuguese, Dutch, Arabic, and Thai. Objective: To translate the professional and self-assessment versions of the SPI to Spanish and to field test the translations. Method: A medically qualified native Spanish speaker translated both versions of the SPI into Spanish. The Spanish translations were discussed by comparing them to blinded back translations into English undertaken by native English speakers; the Spanish texts were then revised in an iterative process involving the translators, 4 dermatologists, and 20 patients. The patients scored their own experience of psoriasis with the self-assessment version and commented on it. The process involved checking the conceptual accuracy of the translation, language-related differences, and subtle gradations of meaning in a process involving all translators and a panel of both Spanish- and English-speaking dermatologists, including a coauthor of the SPI. Results: The final self-assessment and professional Spanish versions of the SPI are presented in this manuscript. Conclusions: Castilian Spanish translations of both versions of the SPI are now available for monitoring disease changes in Spanish-speaking patients with psoriasis under routine clinical care (AU)


Asunto(s)
Humanos , Psoriasis/diagnóstico , Índice de Severidad de la Enfermedad , Comparación Transcultural , Traducciones , España
3.
Actas dermo-sifiliogr. (Ed. impr.) ; 113(4): t363-t369, Abr. 2022. ilus, tab
Artículo en Inglés | IBECS | ID: ibc-206448

RESUMEN

Background: The simplified psoriasis index (SPI) was developed in the United Kingdom to provide a simple summary measure for monitoring changes in psoriasis severity and associated psychosocial impact as well as for obtaining information about past disease behavior and treatment. Two complementary versions of the SPI allow for self-assessment by the patient or professional assessment by a doctor or nurse. Both versions have proven responsive to change, reliable, and interpretable, and to correlate well with assessment tools that are widely used in clinical trials — the Psoriasis Area and Severity Index and the Dermatology Quality of Life Index. The SPI has already been translated into several languages, including French, Brazilian Portuguese, Dutch, Arabic, and Thai. Objective: To translate the professional and self-assessment versions of the SPI to Spanish and to field test the translations. Method: A medically qualified native Spanish speaker translated both versions of the SPI into Spanish. The Spanish translations were discussed by comparing them to blinded back translations into English undertaken by native English speakers; the Spanish texts were then revised in an iterative process involving the translators, 4 dermatologists, and 20 patients. The patients scored their own experience of psoriasis with the self-assessment version and commented on it. The process involved checking the conceptual accuracy of the translation, language-related differences, and subtle gradations of meaning in a process involving all translators and a panel of both Spanish- and English-speaking dermatologists, including a coauthor of the SPI. Results: The final self-assessment and professional Spanish versions of the SPI are presented in this manuscript. Conclusions: Castilian Spanish translations of both versions of the SPI are now available for monitoring disease changes in Spanish-speaking patients with psoriasis under routine clinical care (AU)


Antecedentes: El índice de psoriasis simplificado (SPI) fue desarrollado en el Reino Unido con el fin de proveer un resumen métrico para monitorizar los cambios en la gravedad de la psoriasis (SPI-s) y su impacto social asociado (SPI-p), junto con su comportamiento y tratamiento previo (SPI-i). Existen dos versiones complementarias, una para profesionales de salud, incluidos médicos o enfermeras (proSPI) y otra para la autoevaluación de los pacientes (saSPI). Ambas versiones han demostrado tener una variabilidad al cambio, ser confiables y tener una buena correlación con los instrumentos más utilizados en los estudios clínicos, como el PASI y el DQLI. El SPI estaba ya disponible en versiones adaptadas del francés, portugués (Brasil), holandés, arábigo y tailandés. Objetivo: El objetivo del proyecto actual era producir y probar traducciones del proSPI y saSPI al español. Método: Un médico hispanohablante realizó la primera traducción de ambas versiones al español. Ambas versiones fueron comparadas con sus contratraducciones al inglés de hablantes nativos y luego fueron ajustadas en un proceso repetitivo de múltiples pasos conducidas por traductores, cuatro dermatólogos y veinte pacientes quienes colaboraron con la evaluación del saSPI. Se verificó cuidadosamente la exactitud conceptual al revisar las discrepancias lingüísticas o diferencias sutiles en los significados en un proceso que involucró a todos los traductores y panel incluyendo dermatólogos de habla inglesa como hispana incluyendo a un cocreador del SPI. Resultados: Se presentan en este manuscrito las versiones finales acordadas del SPI en español. Conclusiones: Las versiones del SPI en español (castellano) están ahora disponibles para monitorizar clínicamente a los pacientes con psoriasis (AU)


Asunto(s)
Humanos , Psoriasis/diagnóstico , Índice de Severidad de la Enfermedad , Comparación Transcultural , Traducciones , España
4.
Appl Opt ; 59(10): 3285-3295, 2020 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-32400613

RESUMEN

We present two prescriptions for broadband ($ {\sim} 77 - 252\;{\rm GHz} $), millimeter-wave antireflection coatings for cryogenic, sintered polycrystalline aluminum oxide optics: one for large-format (700 mm diameter) planar and plano-convex elements, the other for densely packed arrays of quasi-optical elements-in our case, 5 mm diameter half-spheres (called "lenslets"). The coatings comprise three layers of commercially available, polytetrafluoroethylene-based, dielectric sheet material. The lenslet coating is molded to fit the 150 mm diameter arrays directly, while the large-diameter lenses are coated using a tiled approach. We review the fabrication processes for both prescriptions, then discuss laboratory measurements of their transmittance and reflectance. In addition, we present the inferred refractive indices and loss tangents for the coating materials and the aluminum oxide substrate. We find that at 150 GHz and 300 K the large-format coating sample achieves $ (97 \pm 2)\% $ transmittance, and the lenslet coating sample achieves $ (94 \pm 3)\% $ transmittance.

5.
Phys Rev Lett ; 123(18): 181301, 2019 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-31763885

RESUMEN

We report the first detection of gravitational lensing due to galaxy clusters using only the polarization of the cosmic microwave background (CMB). The lensing signal is obtained using a new estimator that extracts the lensing dipole signature from stacked images formed by rotating the cluster-centered Stokes QU map cutouts along the direction of the locally measured background CMB polarization gradient. Using data from the SPTpol 500 deg^{2} survey at the locations of roughly 18 000 clusters with richness λ≥10 from the Dark Energy Survey (DES) Year-3 full galaxy cluster catalog, we detect lensing at 4.8σ. The mean stacked mass of the selected sample is found to be (1.43±0.40)×10^{14}M_{⊙} which is in good agreement with optical weak lensing based estimates using DES data and CMB-lensing based estimates using SPTpol temperature data. This measurement is a key first step for cluster cosmology with future low-noise CMB surveys, like CMB-S4, for which CMB polarization will be the primary channel for cluster lensing measurements.

6.
Artículo en Inglés | MEDLINE | ID: mdl-27154359

RESUMEN

We explored the degree to which maternal and offspring outcomes resulting from consuming prenatal docosahexaenoic acid (DHA, 800mg/day) in a clinical trial were influenced by maternal characteristics. Among non-smokers, women who received DHA had heavier babies (adjusted mean difference (MD)=99g 95% CI 45-153, p<0.01; interaction p=0.01) and fewer low birth weight babies than control women (adjusted relative risk=0.43 95% CI 0.25-0.74, p<0.01; interaction p=0.01). From women who had not completed further education, children in the DHA group had higher cognitive scores at 18 months compared with control children (adjusted MD=3.15 95% CI 0.93-5.37, p=0.01; interaction p<0.01). Conversely, the children of women who completed further education in the DHA group had lower language scores than control children (adjusted MD -2.82 95% CI -4.90 to -0.73, p=0.01; interaction p=0.04). Our results support the notion that responsiveness to prenatal DHA may depend on the characteristics of specific population subgroups.


Asunto(s)
Desarrollo Infantil/efectos de los fármacos , Cognición/efectos de los fármacos , Suplementos Dietéticos , Ácidos Docosahexaenoicos/administración & dosificación , Niño , Femenino , Humanos , Embarazo , Atención Prenatal , Factores de Riesgo
7.
Phys Rev Lett ; 116(7): 071301, 2016 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-26943526

RESUMEN

The CDMS low ionization threshold experiment (CDMSlite) uses cryogenic germanium detectors operated at a relatively high bias voltage to amplify the phonon signal in the search for weakly interacting massive particles (WIMPs). Results are presented from the second CDMSlite run with an exposure of 70 kg day, which reached an energy threshold for electron recoils as low as 56 eV. A fiducialization cut reduces backgrounds below those previously reported by CDMSlite. New parameter space for the WIMP-nucleon spin-independent cross section is excluded for WIMP masses between 1.6 and 5.5 GeV/c^{2}.

8.
Phys Rev Lett ; 114(11): 111302, 2015 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-25839256

RESUMEN

While the standard model of particle physics does not include free particles with fractional charge, experimental searches have not ruled out their existence. We report results from the Cryogenic Dark Matter Search (CDMS II) experiment that give the first direct-detection limits for cosmogenically produced relativistic particles with electric charge lower than e/6. A search for tracks in the six stacked detectors of each of two of the CDMS II towers finds no candidates, thereby excluding new parameter space for particles with electric charges between e/6 and e/200.

9.
Phys Rev Lett ; 112(24): 241302, 2014 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-24996080

RESUMEN

We report a first search for weakly interacting massive particles (WIMPs) using the background rejection capabilities of SuperCDMS. An exposure of 577 kg days was analyzed for WIMPs with mass <30 GeV/c(2), with the signal region blinded. Eleven events were observed after unblinding. We set an upper limit on the spin-independent WIMP-nucleon cross section of 1.2×10(-42) cm(2) at 8 GeV/c(2). This result is in tension with WIMP interpretations of recent experiments and probes new parameter space for WIMP-nucleon scattering for WIMP masses <6 GeV/c(2).

10.
Phys Rev Lett ; 112(4): 041302, 2014 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-24580434

RESUMEN

SuperCDMS is an experiment designed to directly detect weakly interacting massive particles (WIMPs), a favored candidate for dark matter ubiquitous in the Universe. In this Letter, we present WIMP-search results using a calorimetric technique we call CDMSlite, which relies on voltage-assisted Luke-Neganov amplification of the ionization energy deposited by particle interactions. The data were collected with a single 0.6 kg germanium detector running for ten live days at the Soudan Underground Laboratory. A low energy threshold of 170 eVee (electron equivalent) was obtained, which allows us to constrain new WIMP-nucleon spin-independent parameter space for WIMP masses below 6 GeV/c2.

11.
Phys Rev Lett ; 111(25): 251301, 2013 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-24483735

RESUMEN

We report results of a search for weakly interacting massive particles (WIMPS) with the silicon detectors of the CDMS II experiment. This blind analysis of 140.2 kg day of data taken between July 2007 and September 2008 revealed three WIMP-candidate events with a surface-event background estimate of 0.41(-0.08)(+0.20)(stat)(-0.24)(+0.28)(syst). Other known backgrounds from neutrons and 206Pb are limited to <0.13 and <0.08 events at the 90% confidence level, respectively. The exposure of this analysis is equivalent to 23.4 kg day for a recoil energy range of 7-100 keV for a WIMP of mass 10 GeV/c2. The probability that the known backgrounds would produce three or more events in the signal region is 5.4%. A profile likelihood ratio test of the three events that includes the measured recoil energies gives a 0.19% probability for the known-background-only hypothesis when tested against the alternative WIMP+background hypothesis. The highest likelihood occurs for a WIMP mass of 8.6 GeV/c2 and WIMP-nucleon cross section of 1.9×10(-41) cm2.

12.
Astrobiology ; 12(3): 247-57, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22352702

RESUMEN

We report on the use of a portable instrument for microbial detection in the Mojave Desert soil and the potential for its use on Mars. The instrument is based on native fluorescence and employs four excitation wavelengths combined with four emission wavelengths. A soil dilution series in which known numbers of Bacillus subtilis spores were added to soil was used to determine the sensitivity of the instrument. We found that the fluorescence of the biological and organic components of the desert soil samples studied can be as strong as the fluorescence of the mineral component of these soils. Using the calibration derived from B. subtilis spores, we estimated that microbial content at our primary sampling site was 10(7) bacteria per gram of soil, a level confirmed by phospholipid fatty acid analysis. At a nearby site, but in a slightly different geological setting, we tested the instrument's ability to map out microbial concentrations in situ. Over a ∼50 m diameter circle, soil microbial concentrations determined with the B. subtilis calibration indicate that the concentrations of microorganisms detected varies from 10(4) to 10(7) cells per gram of soil. We conclude that fluorescence is a promising method for detecting soil microbes in noncontact applications in extreme environments on Earth and may have applications on future missions to Mars.


Asunto(s)
Bacillus subtilis/aislamiento & purificación , Clima Desértico , Microbiología del Suelo , California , Exobiología , Medio Ambiente Extraterrestre , Fluorescencia , Marte , Esporas Bacterianas/aislamiento & purificación
13.
Stem Cell Res ; 7(3): 256-63, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21775237

RESUMEN

Accurate automated cell fate analysis of immunostained human stem cells from 2- and 3-dimensional (2D-3D) images would improve efficiency in the field of stem cell research. Development of an accurate and precise tool that reduces variability and the time needed for human stem cell fate analysis will improve productivity and interpretability of the data across research groups. In this study, we have created protocols for high performance image analysis software Volocity® to classify and quantify cytoplasmic and nuclear cell fate markers from 2D-3D images of human neural stem cells after in vitro differentiation. To enhance 3D image capture efficiency, we optimized the image acquisition settings of an Olympus FV10i® confocal laser scanning microscope to match our quantification protocols and improve cell fate classification. The methods developed in this study will allow for a more time efficient and accurate software based, operator validated, stem cell fate classification and quantification from 2D and 3D images, and yield the highest ≥94.4% correspondence with human recognized objects.


Asunto(s)
Linaje de la Célula , Procesamiento de Imagen Asistido por Computador/métodos , Programas Informáticos , Células Madre/citología , Biomarcadores/metabolismo , Diferenciación Celular , Citoplasma/metabolismo , Humanos , Microscopía Confocal , Reproducibilidad de los Resultados , Células Madre/metabolismo , Factores de Tiempo
14.
Lett Appl Microbiol ; 52(5): 532-7, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21362001

RESUMEN

AIMS: To determine whether glucose in growth medium affects secondary metabolite production and biocontrol efficacy of Pseudomonas chlororaphis O6. METHODS AND RESULTS: The secondary metabolites pyrrolnitrin and phenazines antagonize phytopathogenic fungi. The expression of the prnA gene encoding tryptophan halogenase, the first step in pyrrolnitrin biosynthesis, required the stationary-phase sigma factor, RpoS. Mutations in rpoS and prnA in Ps. chlororaphis O6 eliminated antifungal activity against Rhizoctonia solani and Fusarium graminearum. Pyrrolnitrin production was reduced by glucose in growth media, whereas phenazine levels were increased. The efficacy of Ps. chlororaphis O6 in the biocontrol of tomato late blight was reduced by addition of glucose to the growth medium. CONCLUSIONS: Regulation by glucose of pyrrolnitrin production influenced the efficacy of the biocontrol of tomato leaf blight. SIGNIFICANCE AND IMPACT OF THE STUDY: The nutritional regulation of secondary metabolite production from a soil pseudomonad may account, at least in part, for the variability of biocontrol under field conditions.


Asunto(s)
Antifúngicos/metabolismo , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Glucosa/farmacología , Fenazinas/metabolismo , Pirrolnitrina/metabolismo , Solanum lycopersicum/microbiología , Fusarium/efectos de los fármacos , Fusarium/metabolismo , Glucosa/metabolismo , Solanum lycopersicum/metabolismo , Miconazol/metabolismo , Pseudomonas/efectos de los fármacos , Pseudomonas/genética , Pseudomonas/crecimiento & desarrollo , Pseudomonas/metabolismo
15.
Lett Appl Microbiol ; 49(6): 775-83, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19843215

RESUMEN

AIMS: To compare responses of a soil bacterium to Cu and Cd. METHODS AND RESULTS: In minimal medium, Cd caused a dose-dependent growth stasis of logarithmic phase cells of Pseudomonas putida, strain KT2440, whereas Cu did not compromise growth up to 10 mg l(-1). Proteomics showed changes in accumulation of both membrane and soluble proteins by 6 h of treatment; increased Krebs cycle enzymes were apparent. Transcript analysis showed Cd- and Cu-induced different genes. Cd-induced genes encoding the transcriptional regulator CzrR2; an outer membrane protein associated with lipopolysaccharide stability, H1; two oxidative stress protective proteins and the P-type ATPase, CadA2, associated with Cd(2+) efflux. The genes most responsive to Cu encoded the regulator CopR1 and the outer membrane resistance protein regulated by CopR1, CopB1; a putative porin, PorD and the Cu-binding protein, PacZ or CopZ, and CopA2. CONCLUSIONS: These findings support that a soil pseudomonad restricts internalization of the metals by using different sets of binding proteins and efflux pumps. Activation of mechanisms to protect against oxidative stress also was evident especially with Cd exposure. SIGNIFICANCE AND IMPACT OF THE STUDY: The differential cellular responses to Cd and Cu suggest that risk assessment for Cd and Cu should be different.


Asunto(s)
Cadmio/metabolismo , Cobre/metabolismo , Pseudomonas putida/crecimiento & desarrollo , Microbiología del Suelo , Proteínas Bacterianas/metabolismo , Electroforesis en Gel Bidimensional , Regulación Bacteriana de la Expresión Génica , Estrés Oxidativo , Proteoma/metabolismo , Pseudomonas putida/genética , Pseudomonas putida/metabolismo , ARN Bacteriano/genética , ARN Bacteriano/metabolismo
16.
J Physiol ; 587(Pt 16): 4051-62, 2009 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-19564395

RESUMEN

The neural mechanisms underlying reaction times have previously been modelled in two distinct ways. When stimuli are hard to detect, response time tends to follow a random-walk model that integrates noisy sensory signals. But studies investigating the influence of higher-level factors such as prior probability and response urgency typically use highly detectable targets, and response times then usually correspond to a linear rise-to-threshold mechanism. Here we show that a model incorporating both types of element in series - a detector integrating noisy afferent signals, followed by a linear rise-to-threshold performing decision - successfully predicts not only mean response times but, much more stringently, the observed distribution of these times and the rate of decision errors over a wide range of stimulus detectability. By reconciling what previously may have seemed to be conflicting theories, we are now closer to having a complete description of reaction time and the decision processes that underlie it.


Asunto(s)
Modelos Neurológicos , Percepción de Movimiento/fisiología , Red Nerviosa/fisiología , Tiempo de Reacción/fisiología , Corteza Visual/fisiología , Adulto , Animales , Simulación por Computador , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
18.
Biotechnol Lett ; 30(9): 1559-64, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18414793

RESUMEN

Thraustochytrids, in particular Schizochytrium spp., are used for the production of the valuable polyunsaturated fatty acid, docosahexaenoic acid (DHA; 22:6 n-3). Growth of Schizochytrium sp. G13/2S in a defined medium was initially made in shake-flask cultures to determine the optimum concentrations of glucose (100-200 g l(-1)) and ammonia ( approximately 300 mg l(-1)) that could be used by this microorganism. In subsequent fermenter cultures, a pH-auxostat method was used to maintain NH(3) from 200-300 mg l(-1). During the first 49 h of fermentation, 150 g glucose l(-1) produced 63 g cell dry wt l(-1). Although growth was not limited by the supply of nitrogen, total fatty acids were at 25% cell dry wt which is more than half the final lipid content of commercially-grown Schizochytrium biomass which uses N-limited medium in the final stages for maximum lipid accumulation. This strategy is therefore useful for the cultivation of Schizochytrium to a high cell density up to the point when lipid accumulation can be triggered by N exhaustion.


Asunto(s)
Reactores Biológicos , Técnicas de Cultivo de Célula/métodos , Eucariontes/citología , Compuestos de Amonio Cuaternario/farmacología , Recuento de Células , Eucariontes/efectos de los fármacos , Eucariontes/crecimiento & desarrollo , Ácidos Grasos/análisis , Fermentación/efectos de los fármacos , Glucosa/farmacología , Concentración de Iones de Hidrógeno/efectos de los fármacos
19.
Curr Microbiol ; 56(2): 145-9, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18074175

RESUMEN

Transposon mutagenesis of Pseudomonas chlororaphis O6 was performed with the transposon Tn5 to investigate genes involved in production of secondary metabolites. A mutant, termed Org, produced intense dark-brown pigmentation on rich medium. The Tn5-flanking sequence of the Org mutant showed high homology with the hmgA gene encoding the enzyme homogentisate dioxygenase, involved in the degradation of aromatic amino acids such as tyrosine. Growth of the hmgA mutant on L-tyrosine as sole carbon and energy sources was impaired. Growth on L-tyrosine was restored and production of the brown melanin pigment was eliminated when the mutant was complemented with the wild-type hmgA gene. The change in aromatic amino acids metabolism caused by the deletion of the hmgA gene function did not impair production of phenazines and biological traits connected to these secondary compounds: inhibition of fungal growth and inhibition of barley seed germination.


Asunto(s)
Proteínas Bacterianas/metabolismo , Homogentisato 1,2-Dioxigenasa/metabolismo , Mutación , Pseudomonas/enzimología , Antibiosis , Proteínas Bacterianas/genética , Clonación Molecular , Elementos Transponibles de ADN/genética , Hongos/crecimiento & desarrollo , Regulación Bacteriana de la Expresión Génica , Germinación , Homogentisato 1,2-Dioxigenasa/genética , Hordeum/crecimiento & desarrollo , Mutagénesis Insercional , Pigmentos Biológicos , Pseudomonas/crecimiento & desarrollo , Pseudomonas/fisiología , Semillas/crecimiento & desarrollo , Transcripción Genética , Tirosina/metabolismo
20.
Proc Biol Sci ; 275(1632): 335-44, 2008 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-18055389

RESUMEN

Disappearance of the fixation spot before the appearance of a peripheral target typically reduces average saccadic reaction times (the gap effect) and may also produce a separate population of early or express saccades. The superior colliculus (SC) is generally believed to be critically involved in generating both effects. As the direct sensory input to the SC does not encode colour information, to determine whether this input was critical in generating the gap effect or express saccades we used coloured targets which this pathway cannot distinguish. Our observers still made early saccades to colour-defined targets, but these were anticipations in response to the offset of the non-coloured fixation target. We also show that a gap effect still occurs when either the fixation target or the peripheral target is colour defined, suggesting that direct sensory input to the SC is not required and that information about the location of colour-defined targets is abstracted prior to processing within the SC.


Asunto(s)
Fijación Ocular/fisiología , Tiempo de Reacción , Movimientos Sacádicos/fisiología , Color , Humanos , Estimulación Luminosa/métodos , Factores de Tiempo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...