2,527 research outputs found
Saccharomyces cerevisiae glutaredoxin 5-deficient cells subjected to constitutive oxidizing conditions are affected in the expression of specific sets of genes
The Saccharomyces cerevisiae GRX5 gene codes for a mitochondrial glutaredoxin involved in the synthesis ofiron/sulfur clusters. Its absence prevents respiratory growth and causes the accumulation of iron inside cellsand constitutive oxidation of proteins. Null Δgrx5 mutants were used as an example of continuously oxidizedcells, as opposed to situations in which oxidative stress is instantaneously caused by addition of external oxidants.Whole transcriptome analysis was carried out in the mutant cells. The set of genes whose expression wasaffected by the absence of Grx5 does not significantly overlap with the set of genes affected in respiratorypetite mutants. Many Aft1-dependent genes involved in iron utilization that are up-regulated in a frataxin mutantwere also up-regulated in the absence of Grx5. BIO5 is another Aft1-dependent gene induced both upon irondeprivation and in Δgrx5 cells; this links iron and biotin metabolism. Other genes are specifically affected underthe oxidative conditions generated by the grx5 mutation. One of these is MLP1, which codes for a homologueof the Slt2 kinase. Cells lacking MLP1 and GRX5 are hypersensitive to oxidative stress caused by externalagents and exhibit increased protein oxidation in relation to single mutants. This in turn points to a role forMlp1 in protection against oxidative stress. The genes of the Hap4 regulon, which are involved in respiratorymetabolism, are down-regulated in Δgrx5 cells. This effect is suppressed by HAP4 overexpression. Inhibition ofrespiratory metabolism during continuous moderately oxidative conditions could be a protective response bythe cell
Automatic vacant parking places management system using multicamera vehicle detection
This paper presents a multicamera system for vehicles
detection and their corresponding mapping into the parking
spots of a parking lot. Approaches from the state-of-the-art,
which work properly in controlled scenarios, have been validated
using small amount of sequences and without more challenging
realistic conditions (illumniation changes, different weather). On
the other hand, most of them are not complete systems, but
provide only parts of them, usually detectors. The proposed
system has been designed for realistic scenarios considering
different cases of occlussion, ilumination changes and different
climatic conditions; a real scenario (the International Pittsburgh
Airport parking lot) has been targeted with the condition that
existing parking security cameras can be used, avoiding the
deployment of new cameras or other sensors infrastructures.
For design and validation, a new multicamera dataset has been
recorded. The system is based on existing object detectors (the
results of two of them are shown) and different proposed postprocessing
stages. The results clearly show that the proposed system
works correctly in challenging scenarios including almost total
occlusions, illumination changes and different weather conditionsThis work has been partially supported by the Spanish
Government FPU grant programme (Ministerio de Educación,
Cultura y Deporte) and by the Spanish government under
the project TEC2014-53176-R (HAVideo
The end of the demographic dividend in Latin America: challenges for economic and social policies
Artículo de revistaPopulation ageing is a major global challenge. The Latin American economies have a younger population structure than other emerging and advanced economies, which has allowed them to enjoy the so-called demographic dividend (a favourable working age/non-working age population ratio). However, according to the latest demographic projections of the United Nations (UN), it is estimated that in 2020 the Latin American population pyramid will resemble that of the advanced economies in 1990 and that, by around 2050, both groups will have similar population profiles. This article documents the current demographic trends in Latin America and discusses the main related challenges, in particular, those arising from the adaptation of social welfare systems to population ageing
Experiences on altimeter calibration at Ibiza island and Cape of Begur (Spain)
Three preliminary camp aigns for TOPEX /POSEIDON (T/P) wer e made in March 1999 and July 2000 and for JASON-1 in August 2002, in the NW Mediterran ean Sea at th e Begur Cape area. Dir ect abso lute altimeter calibration , and mapping of the sea surface, w ere made in these camp aigns from dir ect overflights using GPS buoys with a toroidal design performed at the I CC based in the orig inal design of the Univ ersity of Colorado at Boulder and a estimation of the TOPEX A lt- B bias w as made. A Spanish JASON-1 geoid gradien t campaign with Fench support has been made in June 2003 at the Ibiza island in the NW Mediterr anean Sea. Th e main objectiv e has b een to map w ith a new d esign ed, builded and calibrated GPS catamar an, the lo cal geoid gradien t in three ar eas around Ibiza island under the ascending (187) and descending (248) Jason-1ground tracks. The catamaran equ ipped with two GPS antennas to perform continuous sea lev el measur ements was towed by the Patro l Dev a from th e Span ish N avy. Five GPS reference stations were dep loyed on Ibiza island: one in Portinatx, two in San Anton io and two in Ibiza. The marin e geo id has been used to relate the coastal tide gauge data from Ibiza and San An tonio h arbours to off- shore altimetric data. In th e framework of the campaign, the levelling of the Ibiza and San Anton io tide gauges to the r espective GPS mark ers w as p erformed. We present synth esis of the resu lts obtained from Topex/Poseidon and th e first r esults on Jason-1 altimeter calibration using the direct measurements from GPS buoys and the derived marin e geoid. Th e Ibiza results agree relativ ely w ell with resu lts ob tained at Corsica, Harvest and Bass Strait calibration permanen t sites. Moreov er, the geod etic activities (e.g., GPS, levelling) has p ermitted to build a very accurate (few mm) local n etwork link ed to th e European one, w ith a reference frame compatible with th e satellite altimetry missions (ITRF2000). The GPS kinematic data wer e processed using two d ifferen t sof twar es allowing to check th e consistency of the solutions. A perspective of a new Jason-1, in cluding Envisat, Ibiza campaign to be made around 2007 will be pr esen ted. These camp aigns w ere supporte by th e Span ish Ministery of Scien ce and Technology under projects of the N ational Space Program ref : ESP1997-1816-CO4- 03 and ESP2001-4534-PE.Peer ReviewedPostprint (published version
Reference values and improvement of aerodynamic drag in professional cyclists
P. 277-286El objetivo de este estudio fue medir la resistencia aerodinámica en ciclistas profesionales, obtener valores de referencia de la resistencia aerodinámica en posiciones estáticas y de esfuerzo, mejorar el rendimiento de los ciclistas modificando su posición y equipamiento de bicicleta, y evaluar las ventajas y desventajas de estas modificaciones. El estudio se llevó a cabo en un túnel de viento con cinco ciclistas profesionales. Se estudiaron cuatro posiciones con una bicicleta de contrarreloj y una posición con una bicicleta de carreras estándar. En cada posición se registraron la resistencia aerodinámica y las variables cinemáticas. El área de arrastre para la bicicleta de contrarreloj fue 31% mayor en esfuerzo que en posición estática, y
menor que para la bicicleta de carreras estándar. Los cambios en la posición de los ciclistas redujeron la resistencia aerodinámica en un 14%. El aero-casco no fue favorable para todos los ciclistas. La confiabilidad de las medidas de resistencia aerodinámica en el túnel de viento fue alta (r> 0.96, CV <2%). En conclusión, hemos medido y mejorado la resistencia aerodinámica en ciclistas profesionales. Nuestros resultados fueron superiores a los obtenidos por otros estudios que no evaluaron la resistencia aerodinámica durante el esfuerzo a ritmo de carrera y que empleaban diferentes ruedas. Se debatió la eficiencia del aero-casco y la validez, confiabilidad y sensibilidad del túnel de viento y las pruebas aerodinámicas de camp
A stereoselective synthesis of (R)-(-)-rolipram from L-glutamic acid
A stereoselective synthesis of (R)-(-)-rolipram from L-glutamic acid is described. The key step is a stereoselective Michael addition of an arylcuprate to a modified pyroglutamic derivative which acts as the template to induce the stereoselectivity. Facile manipulation of the enantiomerically pure Michael product afforded the expected therapeutic agent.We gratefully acknowledge ZAMBON GROUP for studentships (to A. D. and J. S.) and financial support
Biomechanical assessment of aerodynamic resistance in proffessional cyclists: methodological aspects
El objetivo de este estudio fue medir y comparar, a través de un túnel de viento, la resistencia aerodinámica (RA) en cinco ciclistas profesionales; y establecer modificaciones que mejoraran el rendimiento. Cinco ciclistas profesionales del equipo Kelme-Costa Blanca fueron objeto de estudio, cuatro en bicicleta aerodinámica y uno en bicicleta estándar. De nuestros resultados concluimos que estableciendo pequeñas modificaciones en los manillares, colocándolos en una posición más rentable, se puede reducir la R
CARACTERIZACIÓN DE LAS PROPIEDADES NUTRICIONALES Y ANTIOXIDANTES DE SEMILLAS DE QUINUA (Chenopodium quinoa WILLD.)
[EN] Interest in the cultivation of quinoa pseudo-cereal (Chenopodium quinoa Willd.) has increased in recent years due to its nutritional value, as well as its antioxidant capacity and phytochemical content. The chemical composition of quinoa seeds and their bioactive compounds can differ between varieties. In this study, the nutritional composition, antioxidant properties and total phenolic content of Yellow quinoa seeds cultivated in Mexico were evaluated. The results were compared with four commercial quinoa varieties from Peru: Yellow, Black, Red and Peruvian Yellow. The chemical composition of seeds in this study varied as a function of germplasm and growing conditions. In general, samples were characterized by their high carbohydrate content, followed by protein, lipids and fiber. The Yellow quinoa grown in Mexico stood out for its high phenolic content, as well as for its antioxidant activity, probably influenced by the presence of saponins.Carranza-Concha, J.; Chairez-Huerta, SG.; Contreras-Martinez, CS.; García Martínez, EM. (2021). Characterization of nutritional and antioxidant properties of Quinoa seeds (Chenopodium quinoa WILLD.). Revista Fitotecnia Mexicana. 44(3):357-366. http://hdl.handle.net/10251/18680435736644
Oral and dental health status in patients with eating disorders in Madrid, Spain
The aim of the present study was to describe and compare the oral and dental health status of two groups, one diagnosed with eating disorders (EDs), and another group without this pathology, assessing the following oral manifestations: dental alterations, periodontal disorders, soft tissue disorders, non-stimulated salivary flow, and oral pH. This comparative transversal epidemiological study included 179 participants, of whom 59 were diagnosed with EDs (Eating Disorder Group: EDG) and 120 had no antecedents of EDs (No Eating Disorder Group: NEDG). All patients fulfilled the following inclusion criteria: women aged over 18 years, diagnosed with an ED by a specialist, patients who had undergone at least 1 year monitoring by the Clinical Nutrition Unit, and had not received any periodontal treatment during the previous 6 months. Both groups were homogeneous in terms of sex, age, education, and socioeconomic level. Oral exploration was performed, registering clinical variables, as well as sociodemographic and socioeconomic data, oral hygiene habits, and smoking. Statistical significance was established as p 95%). The dental erosion (DE) was the most significative feature of dental alterations. The degree of DE was significantly greater in the EDG (p<0.001). A significant association between soft tissue lesions and EDs was found (p<0.001) A notable difference in non-stimulated salivary flow was found between the groups (p<0.001). No significant differences between the groups were found for periodontal status, dental caries, or oral hygiene practices. On the basis of the results obtained, it is necessary to carry out oral/dental examination as soon as an ED is diagnosed with regular check-ups thereafter
The Effect of Cholesterol on the Long-Range Network of Interactions Established among Sea Anemone Sticholysin II Residues at the Water-Membrane Interface
Actinoporins are α-pore forming proteins with therapeutic potential, produced by sea anemones. Sticholysin II (StnII) from Stichodactyla helianthus is one of its most extensively characterized members. These proteins remain stably folded in water, but upon interaction with lipid bilayers, they oligomerize to form a pore. This event is triggered by the presence of sphingomyelin (SM), but cholesterol (Chol) facilitates pore formation. Membrane attachment and pore formation require changes involving long-distance rearrangements of residues located at the protein-membrane interface. The influence of Chol on membrane recognition, oligomerization, and/or pore formation is now studied using StnII variants, which are characterized in terms of their ability to interact with model membranes in the presence or absence of Chol. The results obtained frame Chol not only as an important partner for SM for functional membrane recognition but also as a molecule which significantly reduces the structural requirements for the mentioned conformational rearrangements to occur. However, given that the DOPC:SM:Chol vesicles employed display phase coexistence and have domain boundaries, the observed effects could be also due to the presence of these different phases on the membrane. In addition, it is also shown that the Arg51 guanidinium group is strictly required for membrane recognition, independently of the presence of Chol
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