Hair ageing in Black women (age>59): impact on personal and social identity and subjective wellbeing

This interdisciplinary study explores the evolution of hair management practices of Black women from age-related biological, personal and social perspectives. It seeks to clarify if and how any changes impact the subjective wellbeing of women. The study focuses on Black women living in the UK who are 59 years old and over as biological changes to hair become more prominent after menopause. The study contributes to raising the visibility of this group of women who appear underrepresented in the research fields of hair science, well-being and ageing as well as in the media

The Orphan G Protein-coupled Receptors GPR41 and GPR43 Are Activated by Propionate and Other Short Chain Carboxylic Acids

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Nuevo explante para la embriogénesis somática en Sorghum bicolor (L.) Mohen

This work was carried out with the objective to form somatic embryos of sorghum, cv. ‘CIAP 132R-05’ starting from callus obtained from sections of in vitro shoots. For the formation of callus, different concentrations of 2,4-D were studied as well as three concentrations of ascorbic acid to eliminate the phenolic oxidation. To increase the percentage of callus formation with embryogenic structures, different segments of the shoots were used. For the formation of somatic embryos, different concentrations of 2,4-D; 6-BAP and L-Proline were added to the culture media. The greatest callus formation (50%) was obtained in the culture medium with 18.1 µM of 2,4-D. When 50 mg l -1  of ascorbic acid was added to the culture medium, the percentage of callus formation increased to 67.5%, and was couple with absence of oxidation of the medium and the explant. The frequency of callus formation with embryogenic structures increased to 95% with the use of segment 1 of the shoot sections in vitro as explant. The greatest number of somatic embryos per callus was obtained when 2,4-D was reduced to 4.52 µM, combined with 22.2 µM of 6-BAP and 500 mg l -1  of L-Proline (41.88). Histological analysis confirmed that structures formed in callus came from a somatic embryogenesis process. For the first time, the efficient formation of somatic embryos of sorghum section 1 of in vitro shoots in vitro was obtained.Keywords: 2,4-D, shoots in vitro, callus, somatic embryosEl trabajo fue realizado con el objetivo de formar embriones somáticos de sorgo, variedad ‘CIAP 132R-05’ a partir de callos obtenidos de secciones de brotes in vitro. En la formación de callos fueron estudiadas diferentes concentraciones de 2,4 D y tres concentraciones de ácido ascórbico para eliminar la oxidación fenólica. Para incrementar el porcentaje de formación de callos con estructuras embriogénicas fueron empleados diferentes segmentos de brote. Se añadieron diferentes concentraciones de 2,4-D, 6-BAP y L- prolina al medio de cultivo para la formación de embriones somáticos. La mayor formación de callos (50%) se obtuvo en el medio de cultivo con 18.1 µM de 2,4-D. Cuando se añadieron 50 mg l -1  de ácido ascórbico al medio de cultivo, el porcentaje de formación de callos se incrementó en 67.5%, unido a la ausencia de pigmentos fenólicos en el explante. La frecuencia de formación de callos con estructuras embriogénicas aumento hasta 95% con el uso del segmento 1 como explante. El mayor número de embriones somáticos por callos se obtuvo cuando 2,4-D fue reducido a 4.52 µM, combinado con 2.22 µM de 6-BAP y 500 mg l -1  de L-prolina (41.88). El análisis histológico confirmó que las estructuras formadas a partir de los callos provienen del proceso de embriogénesis somática. Por vez primera se obtuvo la formación eficiente de embriones somáticos de sorgo de a partir de la seccion 1 de brotes in vitro.Palabras clave: 2,4-D, brotes in vitro, callos, embriones somático

Group II Intron-Based Gene Targeting Reactions in Eukaryotes

Mobile group II introns insert site-specifically into DNA target sites by a mechanism termed retrohoming in which the excised intron RNA reverse splices into a DNA strand and is reverse transcribed by the intron-encoded protein. Retrohoming is mediated by a ribonucleoprotein particle that contains the intron-encoded protein and excised intron RNA, with target specificity determined largely by base pairing of the intron RNA to the DNA target sequence. This feature enabled the development of mobile group II introns into bacterial gene targeting vectors ("targetrons") with programmable target specificity. Thus far, however, efficient group II intron-based gene targeting reactions have not been demonstrated in eukaryotes.By using a plasmid-based Xenopus laevis oocyte microinjection assay, we show that group II intron RNPs can integrate efficiently into target DNAs in a eukaryotic nucleus, but the reaction is limited by low Mg(2+) concentrations. By supplying additional Mg(2+), site-specific integration occurs in up to 38% of plasmid target sites. The integration products isolated from X. laevis nuclei are sensitive to restriction enzymes specific for double-stranded DNA, indicating second-strand synthesis via host enzymes. We also show that group II intron RNPs containing either lariat or linear intron RNA can introduce a double-strand break into a plasmid target site, thereby stimulating homologous recombination with a co-transformed DNA fragment at frequencies up to 4.8% of target sites. Chromatinization of the target DNA inhibits both types of targeting reactions, presumably by impeding RNP access. However, by using similar RNP microinjection methods, we show efficient Mg(2+)-dependent group II intron integration into plasmid target sites in zebrafish (Danio rerio) embryos and into plasmid and chromosomal target sites in Drosophila melanogster embryos, indicating that DNA replication can mitigate effects of chromatinization.Our results provide an experimental foundation for the development of group II intron-based gene targeting methods for higher organisms

REVERBa couples the circadian clock to hepatic glucocorticoid action.

The glucocorticoid receptor (GR) is a major drug target in inflammatory disease. However, chronic glucocorticoid (GC) treatment leads to disordered energy metabolism, including increased weight gain, adiposity, and hepatosteatosis - all programs modulated by the circadian clock. We demonstrated that while antiinflammatory GC actions were maintained irrespective of dosing time, the liver was significantly more GC sensitive during the day. Temporal segregation of GC action was underpinned by a physical interaction of GR with the circadian transcription factor REVERBa and co-binding with liver-specific hepatocyte nuclear transcription factors (HNFs) on chromatin. REVERBa promoted efficient GR recruitment to chromatin during the day, acting in part by maintaining histone acetylation, with REVERBa-dependent GC responses providing segregation of carbohydrate and lipid metabolism. Importantly, deletion of Reverba inverted circadian liver GC sensitivity and protected mice from hepatosteatosis induced by chronic GC administration. Our results reveal a mechanism by which the circadian clock acts through REVERBa in liver on elements bound by HNF4A/HNF6 to direct GR action on energy metabolism

Performance of novel VUV-sensitive Silicon Photo-Multipliers for nEXO

Liquid xenon time projection chambers are promising detectors to search for neutrinoless double beta decay (0$\nu \beta \beta$), due to their response uniformity, monolithic sensitive volume, scalability to large target masses, and suitability for extremely low background operations. The nEXO collaboration has designed a tonne-scale time projection chamber that aims to search for 0$\nu \beta \beta$ of \ce{^{136}Xe} with projected half-life sensitivity of $1.35\times 10^{28}$~yr. To reach this sensitivity, the design goal for nEXO is $\leq$1\% energy resolution at the decay $Q$-value ($2458.07\pm 0.31$~keV). Reaching this resolution requires the efficient collection of both the ionization and scintillation produced in the detector. The nEXO design employs Silicon Photo-Multipliers (SiPMs) to detect the vacuum ultra-violet, 175 nm scintillation light of liquid xenon. This paper reports on the characterization of the newest vacuum ultra-violet sensitive Fondazione Bruno Kessler VUVHD3 SiPMs specifically designed for nEXO, as well as new measurements on new test samples of previously characterised Hamamatsu VUV4 Multi Pixel Photon Counters (MPPCs). Various SiPM and MPPC parameters, such as dark noise, gain, direct crosstalk, correlated avalanches and photon detection efficiency were measured as a function of the applied over voltage and wavelength at liquid xenon temperature (163~K). The results from this study are used to provide updated estimates of the achievable energy resolution at the decay $Q$-value for the nEXO design