Functional connectivity can be measured during task-based functional magnetic resonance imaging (fMRI), or in the absence of specific stimuli or tasks. In either case, the study of low frequency ...fluctuations in the BOLD signal reveals patterns of synchronization which delineate the intrinsic functional architecture of the brain. The scientific community now has available shared resources to accelerate the exploitation of resting state fMRI with the objectives of improving diagnostic methods and leading to better treatments grounded in neuroscience. Fomenting a collaborative scientific culture will accelerate our understanding of the underlying phenonmemna. Recently, the Spanish Resting State Network (SRSN) has joined this collaborative effort by creating a setting to facilitate collaboration among the various neuroscience research groups working in Spanish (http://www.nitrc.org/projects/srsn).
•
Premise of the study:
Nuclear microsatellite primers were developed for the weedy herb
Anacyclus clavatus
to study the genetic structure of hybrid zones with closely related taxa in the western ...Mediterranean Basin, where different floral phenotypes are present.
•
Methods and Results:
We obtained two microsatellite libraries using next-generation sequencing and Sanger sequencing of cloned restriction fragments. A total of 13 polymorphic and 11 monomorphic loci were identified in three Iberian populations of
A. clavatus
. The primers amplified di- and trinucleotide repeats with 1–8 alleles per locus. Most primers also amplified in
A. homogamos
,
A. monanthos
,
A. radiatus
, and
A. valentinus
.
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Conclusions:
These results indicate the utility of these markers in
A. clavatus
for population genetic and hybridization studies as well as their applicability across the genus.
High-risk human papillomavirus (HPV) types cause most cervical carcinomas and are sexually transmitted. Sexual behavior therefore
affects HPV exposure and its cancer sequelae. The International ...Collaboration of Epidemiological Studies of Cervical Cancer
has combined data on lifetime number of sexual partners and age at first sexual intercourse from 21 studies, or groups of
studies, including 10,773 women with invasive cervical carcinoma, 4,688 women with cervical intraepithelial neoplasia grade
3 (CIN3)/carcinoma in situ , and 29,164 women without cervical carcinoma. Relative risks for invasive cancer and CIN3 were estimated by conditional logistic
regression. Risk of invasive cervical carcinoma increased with lifetime number of sexual partners ( P for linear trend <0.001). The relative risk for ≥6 versus 1 partner, conditioned on age, study, and age at first intercourse,
was 2.27 95% confidence interval (95% CI), 1.98-2.61 and increased to 2.78 (95% CI, 2.22-3.47) after additional conditioning
on reproductive factors. The risk of invasive cervical carcinoma increased with earlier age at first intercourse ( P for linear trend <0.001). The relative risk for age at first intercourse ≤14 versus ≥25 years, conditioned on age, study,
and lifetime number of sexual partners was 3.52 (95% CI, 3.04-4.08), which decreased to 2.05 (95% CI, 1.54-2.73) after additional
conditioning on reproductive factors. CIN3/carcinoma in situ showed a similar association with lifetime number of sexual partners; however, the association with age at first intercourse
was weaker than for invasive carcinoma. Results should be interpreted with caution given the strong correlation between sexual
and reproductive factors and the limited information on HPV status. (Cancer Epidemiol Biomarkers Prev 2009;18(4):1060–9)
Heat management is crucial in the design of nanoscale devices as the operating temperature determines their efficiency and lifetime. Past experimental and theoretical works exploring nanoscale heat ...transport in semiconductors addressed known deviations from Fourier's law modeling by including effective parameters, such as a size-dependent thermal conductivity. However, recent experiments have qualitatively shown new behavior that cannot be modeled in this way. Here, we combine advanced experiment and theory to show that the cooling of 1D- and 2D-confined nanoscale hot spots on silicon can be described using a general hydrodynamic heat transport model, contrary to previous understanding of heat flow in bulk silicon. We use a comprehensive set of extreme ultraviolet scatterometry measurements of non-diffusive transport from transiently heated nanolines and nanodots to validate and generalize our ab initio model, that does not need any geometry-dependent fitting parameters. This allows us to uncover the existence of two distinct timescales and heat transport mechanisms: an interface resistance regime that dominates on short time scales, and a hydrodynamic-like phonon transport regime that dominates on longer timescales. Moreover, our model can predict the full thermomechanical response on nanometer length scales and picosecond time scales for arbitrary geometries, providing an advanced practical tool for thermal management of nanoscale technologies. Furthermore, we derive analytical expressions for the transport timescales, valid for a subset of geometries, supplying a route for optimizing heat dissipation.
A mathematical model is presented for thermal transport in nanowires with rectangular cross sections. Expressions for the effective thermal conductivity of the nanowire across a range of temperatures ...and cross-sectional aspect ratios are obtained by solving the Guyer--Krumhansl hydrodynamic equation for the thermal flux with a slip boundary condition. Our results show that square nanowires transport thermal energy more efficiently than rectangular nanowires due to optimal separation between the boundaries. However, circular nanowires are found to be even more efficient than square nanowires due to the lack of corners in the cross section, which locally reduce the thermal flux and inhibit the conduction of heat. By using a temperature-dependent slip coefficient, we show that the model is able to accurately capture experimental data of the effective thermal conductivity obtained from Si nanowires, demonstrating that phonon hydrodynamics is a powerful framework that can be applied to nanosystems even at room temperature.
El análisis de la conectividad funcional mediante resonancia magnética funcional (RMf) puede llevarse a cabo durante la realización de una tarea, la percepción de un estímulo o en estado de reposo. ...Estos análisis han demostrado su fiabilidad y reproducibilidad con diferentes enfoques (matemáticos, estadísticos, físicos) para seleccionar los vóxeles activados. El estudio de la señal de baja frecuencia en la actividad cerebral a través del contraste BOLD en estado de reposo ha revelado patrones de actividad cortical sincronizados, permitiendo describir la arquitectura funcional intrínseca del cerebro humano. La comunidad científica internacional dispone de recursos compartidos que contribuirán mediante este análisis de RMf en estado de reposo a la obtención de diagnósticos y tratamientos más precisos y avanzados en el campo de las neurociencias.
Biological activity of natural retinoids requires the oxidation of retinol to retinoic acid (RA) and its binding to specific nuclear receptors in target tissues. The first step of this pathway, the ...reversible oxidoreduction of retinol to retinaldehyde, is essential to control RA levels. The enzymes of retinol oxidation are NAD-dependent dehydrogenases of the cytosolic medium-chain (MDR) and the membrane-bound short-chain (SDR) dehydrogenases/reductases. Retinaldehyde reduction can be performed by SDR and aldoaketo reductases (AKR), while its oxidation to RA is carried out by aldehyde dehydrogenases (ALDH). In contrast to SDR, AKR and ALDH are cytosolic. A common property of these enzymes is that they only use free retinoid, but not retinoid bound to cellular retinol binding protein (CRBP). The relative contribution of each enzyme type in retinoid metabolism is discussed in terms of the different subcellular localization, topology of membrane-bound enzymes, kinetic constants, binding affinity of CRBP for retinol and retinaldehyde, and partition of retinoid pools between membranes and cytoplasm. The development of selective inhibitors for AKR enzymes 1B1 and 1B10, of clinical relevance in diabetes and cancer, granted the investigation of some structure-activity relationships. Kinetics with the 4-methyl derivatives of retinaldehyde isomers was performed to identify structural features for substrate specificity. Hydrophilic derivatives were better substrates than the more hydrophobic compounds. We also explored the inhibitory properties of some synthetic retinoids, known for binding to retinoic acid receptors (RAR) and retinoid X receptors (RXR). Consistent with its substrate specificity towards retinaldehyde, AKR1B10 was more effectively inhibited by synthetic retinoids than AKR1B1. A RARbeta/gamma agonist (UVI2008) inhibited AKR1B10 with the highest potency and selectivity, and docking simulations predicted that its carboxyl group binds to the anion-binding pocket.
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