Constraining the Star Formation Histories in Dark Matter Halos: I. Central Galaxies

Using the self-consistent modeling of the conditional stellar mass functions across cosmic time by Yang et al. (2012), we make model predictions for the star formation histories (SFHs) of {\it central} galaxies in halos of different masses. The model requires the following two key ingredients: (i) mass assembly histories of central and satellite galaxies, and (ii) local observational constraints of the star formation rates of central galaxies as function of halo mass. We obtain a universal fitting formula that describes the (median) SFH of central galaxies as function of halo mass, galaxy stellar mass and redshift. We use this model to make predictions for various aspects of the star formation rates of central galaxies across cosmic time. Our main findings are the following. (1) The specific star formation rate (SSFR) at high $z$ increases rapidly with increasing redshift [$\propto (1+z)^{2.5}$] for halos of a given mass and only slowly with halo mass ($\propto M_h^{0.12}$) at a given $z$, in almost perfect agreement with the specific mass accretion rate of dark matter halos. (2) The ratio between the star formation rate (SFR) in the main-branch progenitor and the final stellar mass of a galaxy peaks roughly at a constant value, $\sim 10^{-9.3} h^2 {\rm yr}^{-1}$, independent of halo mass or the final stellar mass of the galaxy. However, the redshift at which the SFR peaks increases rapidly with halo mass. (3) More than half of the stars in the present-day Universe were formed in halos with 10^{11.1}\msunh < M_h < 10^{12.3}\msunh in the redshift range $0.4 < z < 1.9$. (4) ... [abridged]Comment: 15 figures, 22 pages, Accepted for publication in Ap

Electronic Structure, Surface Doping, and Optical Response in Epitaxial WSe2 Thin Films

High quality WSe2 films have been grown on bilayer graphene (BLG) with layer-by-layer control of thickness using molecular beam epitaxy (MBE). The combination of angle-resolved photoemission (ARPES), scanning tunneling microscopy/spectroscopy (STM/STS), and optical absorption measurements reveal the atomic and electronic structures evolution and optical response of WSe2/BLG. We observe that a bilayer of WSe2 is a direct bandgap semiconductor, when integrated in a BLG-based heterostructure, thus shifting the direct-indirect band gap crossover to trilayer WSe2. In the monolayer limit, WSe2 shows a spin-splitting of 475 meV in the valence band at the K point, the largest value observed among all the MX2 (M = Mo, W; X = S, Se) materials. The exciton binding energy of monolayer-WSe2/BLG is found to be 0.21 eV, a value that is orders of magnitude larger than that of conventional 3D semiconductors, yet small as compared to other 2D transition metal dichalcogennides (TMDCs) semiconductors. Finally, our finding regarding the overall modification of the electronic structure by an alkali metal surface electron doping opens a route to further control the electronic properties of TMDCs

The MBD7 complex promotes expression of methylated transgenes without significantly altering their methylation status.

DNA methylation is associated with gene silencing in eukaryotic organisms. Although pathways controlling the establishment, maintenance and removal of DNA methylation are known, relatively little is understood about how DNA methylation influences gene expression. Here we identified a METHYL-CpG-BINDING DOMAIN 7 (MBD7) complex in Arabidopsis thaliana that suppresses the transcriptional silencing of two LUCIFERASE (LUC) reporters via a mechanism that is largely downstream of DNA methylation. Although mutations in components of the MBD7 complex resulted in modest increases in DNA methylation concomitant with decreased LUC expression, we found that these hyper-methylation and gene expression phenotypes can be genetically uncoupled. This finding, along with genome-wide profiling experiments showing minimal changes in DNA methylation upon disruption of the MBD7 complex, places the MBD7 complex amongst a small number of factors acting downstream of DNA methylation. This complex, however, is unique as it functions to suppress, rather than enforce, DNA methylation-mediated gene silencing

Psychometric properties of the Child Health Assessment Questionnaire (CHAQ) applied to children and adolescents with cerebral palsy

<p>Abstract</p> <p>Background</p> <p>Cerebral palsy (CP) patients have motor limitations that can affect functionality and abilities for activities of daily living (ADL). Health related quality of life and health status instruments validated to be applied to these patients do not directly approach the concepts of functionality or ADL. The Child Health Assessment Questionnaire (CHAQ) seems to be a good instrument to approach this dimension, but it was never used for CP patients. The purpose of the study was to verify the psychometric properties of CHAQ applied to children and adolescents with CP.</p> <p>Methods</p> <p>Parents or guardians of children and adolescents with CP, aged 5 to 18 years, answered the CHAQ. A healthy group of 314 children and adolescents was recruited during the validation of the CHAQ Brazilian-version. Data quality, reliability and validity were studied. The motor function was evaluated by the Gross Motor Function Measure (GMFM).</p> <p>Results</p> <p>Ninety-six parents/guardians answered the questionnaire. The age of the patients ranged from 5 to 17.9 years (average: 9.3). The rate of missing data was low (<9.3%). The floor effect was observed in two domains, being higher only in the visual analogue scales (≤ 35.5%). The ceiling effect was significant in all domains and particularly high in patients with quadriplegia (81.8 to 90.9%) and extrapyramidal (45.4 to 91.0%). The Cronbach alpha coefficient ranged from 0.85 to 0.95. The validity was appropriate: for the discriminant validity the correlation of the <it>disability index </it>with the visual analogue scales was not significant; for the convergent validity CHAQ <it>disability index </it>had a strong correlation with the GMFM (0.77); for the divergent validity there was no correlation between GMFM and the pain and overall evaluation scales; for the criterion validity GMFM as well as CHAQ detected differences in the scores among the clinical type of CP (p < 0.01); for the construct validity, the patients' <it>disability index </it>score (mean:2.16; SD:0.72) was higher than the healthy group (mean:0.12; SD:0.23)(p < 0.01).</p> <p>Conclusion</p> <p>CHAQ reliability and validity were adequate to this population. However, further studies are necessary to verify the influence of the ceiling effect on the responsiveness of the instrument.</p

Mass Transfer and Volume Changes in French Fries During Air Frying

An erratum to this article can be found at http://dx.doi.org/10.1007/s11947-012-0904-8 (The graph located in the left upper corner of Fig. 2 is incorrect)The production of healthier fried foods requires the adaptation of industrial processes. In this context, air frying is an alternative to deep oil frying to obtain French fries with lower fat content. Kinetic analysis of compositional changes and main fluxes involved in air frying were carried out, and the results were compared to those obtained for deep oil frying. The influence of the type of sample (unpretreated, frozen, or blanched potatoes) was also analyzed. The results showed that oil uptake is much lower in air frying although a much longer processing time is required. Also, water loss and thus the loss of volume were much higher in air frying compared to the conventional process.The authors would like to thank the Universitat Politecnica de Valencia (PAID-06-09-2876) for the financial support given to this investigation.Andrés Grau, AM.; Argüelles Foix, AL.; Castelló Gómez, ML.; Heredia Gutiérrez, AB. (2013). Mass Transfer and Volume Changes in French Fries During Air Frying. Food and Bioprocess Technology. 6(8):1917-1924. https://doi.org/10.1007/s11947-012-0861-2S1917192468Aguilar, C. N., Anzaldúa-Morales, R., Talamás, R., & Gastélum, G. (1997). Low-temperature blanch improves textural quality of French-fries. Journal of Food Science, 62, 568–571.AOAC. (1980). Official methods of analysis (12th ed.). Washington, D.C., USA: Association of Official Analytical Chemists.Califano, A. N., & Calvelo, A. (1987). Adjustment of surface concentration of reducing sugars before frying of potato strips. Journal of Food Processing and Preservation, 12, 1–9.Clark, J. P. (2003). Happy birthday, potato chip! And other snack developments. Food Technology, 57(5), 89–92.Debnath, S., Bhat, K. K., & Rastogi, N. K. (2003). Effect of pre-drying on kinetics of moisture loss and oil uptake during deep fat frying of chickpea flour-based snack food. LWT—Food Science and Technology, 36, 91–98.Du Pont, M. S., Kirby, A. B., & Smith, A. C. (1992). Instrumental and sensory tests of cooked frozen French fries. International Journal of Food Science and Technology, 27, 285–295.Dueik, V., Robert, P., & Bouchon, P. (2010). Vacuum frying reduces oil uptake and improves the quality parameters of carrot crisps. Food Chemistry, 119(3), 1143–1149.Hubbard, L. J., & Farkas, B. E. (2000). Influence of oil temperature on convective heat transfer during immersion frying. Journal of Food Processing and Preservation, 24(2), 143–162.Krokida, M. K., Oreopoulou, V., & Maroulis, Z. B. (2000). Water loss and oil uptake as a function of frying time. Journal of Food Engineering, 44, 39–46.Mestdagh, F., De Wilde, T., Fraselle, S., Govaert, Y., Ooghe, W., Degroodt, J. M., Verhé, R., Van Peteghem, C., & De Meulenaer, B. (2008). Optimization of the blanching process to reduce acrylamide in fried potatoes. LWT- Food Science and Technology, 41(9), 1648–1654.Mohsenin, N. M. (1986). Physical properties of plant and animal materials. Nueva York: Gordon and Breach.Moyano, P. C., & Pedreschi, F. (2006). Kinetics of oil uptake during frying of potato slices: effect of pre-treatments. LWT- Food Science and Technology, 39, 285–291.Ngadi, M. O., Wang, Y., Adedeji, A. A., & Raghavan, G. S. V. (2009). Effect of microwave pretreatment on mass transfer during deep-fat frying of chicken nugget. LWT- Food Science and Technology, 42(1), 438–440.Pedreschi, F., & Moyano, P. (2005). Oil uptake and texture development in fried potato slices. Journal of Food Engineering, 70(4), 557–563.Saguy, S., & Dana, D. (2003). Integrated approach to deep fat frying: engineering, nutrition, health and consumer aspects. Journal of Food Engineering, 56, 143–152.Troncoso, E., & Pedreschi, F. (2009). Modeling water loss and oil uptake during vacuum frying of pre-treated potato slices. LWT- Food Science and Technology, 42(6), 1164–1173

Synergistic Effect of Functionalized Nickel Nanoparticles and Quercetin on Inhibition of the SMMC-7721 Cells Proliferation

The effect of functionalized nickel (Ni) nanoparticles capped with positively charged tetraheptylammonium on cellular uptake of drug quercetin into hepatocellular carcinoma cells (SMMC-7721) has been explored in this study via microscopy and electrochemical characterization as well as MTT assay. Meanwhile, the influence of Ni nanoparticles and/or quercetin on cell proliferation has been further evaluated by the real-time cell electronic sensing (RT-CES) study. Our observations indicate that Ni nanoparticles could efficiently improve the permeability of cancer cell membrane, and remarkably enhance the accumulation of quercetin in SMMC-7721 cells, suggesting that Ni nanoparticles and quercetin would facilitate the synergistic effect on inhibiting proliferation of cancer cells

First report of an HIV-1 triple recombinant of subtypes B, C and F in Buenos Aires, Argentina

We describe the genetic diversity of currently transmitted strains of HIV-1 in men who have sex with men (MSM) in Buenos Aires, Argentina between 2000 and 2004. Nearly full-length sequence analysis of 10 samples showed that 6 were subtype B, 3 were BF recombinant and 1 was a triple recombinant of subtypes B, C and F. The 3 BF recombinants were 3 different unique recombinant forms. Full genome analysis of one strain that was subtype F when sequenced in pol was found to be a triple recombinant. Gag and pol were predominantly subtype F, while gp120 was subtype B; there were regions of subtype C interspersed throughout. The young man infected with this strain reported multiple sexual partners and sero-converted between May and November of 2004. This study reported for the first time the full genome analysis of a triple recombinant between subtypes B, C and F, that combines in one virus the three most common subtypes in South America

Caspase-8 binding to cardiolipin in giant unilamellar vesicles provides a functional docking platform for bid

Caspase-8 is involved in death receptor-mediated apoptosis in type II cells, the proapoptotic programme of which is triggered by truncated Bid. Indeed, caspase-8 and Bid are the known intermediates of this signalling pathway. Cardiolipin has been shown to provide an anchor and an essential activating platform for caspase-8 at the mitochondrial membrane surface. Destabilisation of this platform alters receptor-mediated apoptosis in diseases such as Barth Syndrome, which is characterised by the presence of immature cardiolipin which does not allow caspase-8 binding. We used a simplified in vitro system that mimics contact sites and/or cardiolipin-enriched microdomains at the outer mitochondrial surface in which the platform consisting of caspase-8, Bid and cardiolipin was reconstituted in giant unilamellar vesicles. We analysed these vesicles by flow cytometry and confirm previous results that demonstrate the requirement for intact mature cardiolipin for caspase-8 activation and Bid binding and cleavage. We also used confocal microscopy to visualise the rupture of the vesicles and their revesiculation at smaller sizes due to alteration of the curvature following caspase-8 and Bid binding. Biophysical approaches, including Laurdan fluorescence and rupture/tension measurements, were used to determine the ability of these three components (cardiolipin, caspase-8 and Bid) to fulfil the minimal requirements for the formation and function of the platform at the mitochondrial membrane. Our results shed light on the active functional role of cardiolipin, bridging the gap between death receptors and mitochondria

The contribution of concentric electrode-evoked potentials and nociceptive withdrawal reflex to the routine neurophysiological assessment of neuropathic pain:cross-sectional study

BACKGROUND AND OBJECTIVES:Conventional electrodiagnostic studies (EDX) are frequently used to support the diagnosis of peripheral neuropathic pain. However, routine EDX has poor diagnostic yield for identifying small fiber neuropathy, which may be cause of neuropathic pain in some patients. This study aimed to assess the gain in diagnostic yield brought by adding pain-related evoked potentials with concentric electrode (CN-PREP) and nociceptive withdrawal reflex (NWR) assessments to EDX.METHODS:Transversal observational accuracy study which included patients referred to routine EDX in a tertiary-care hospital who reported chronic neuropathic pain in their lower limbs. Besides routine EDX, subjects underwent CN-PREP and NWR assessments. Diagnostic yield and tolerability were examined and compared between test studies.RESULTS:The study enrolled 100 patients (54% female), with 57 ± 12 years. EDX was altered in 47% of all patients. The addition of CN-PREP alone, and NWR combined with CN-PREP increased diagnostic yield to 69% and 72%, respectively. CN-PREP proved to be well tolerable, while NWR was associated with higher test-related pain intensity and discontinuation rate (9% vs. 0%). Considering EDX as the reference test, CN-PREP sensitivity was 85.1% and specificity 58.5%.CONCLUSION:Combining CN-PREP with the routine EDX for patients with neuropathic pain is feasible and results in increased diagnostic yield. Conversely, the addition of NWR to the aforementioned tests provides little improvement to this yield and is less tolerable to the patient. Further studies are needed to determine the actual sensitivity and specificity of CN-PREP when compared to the gold-standard for small fiber neuropathy diagnosis, i.e. intraepidermal nerve fiber density assessment

Proximity-Induced Nucleic Acid Degrader (PINAD) approach to targeted RNA degradation using small molecules

Nature has evolved intricate machinery to target and degrade RNA, and some of these molecular mechanisms can be adapted for therapeutic use. Small interfering RNAs and RNase H-inducing oligonucleotides have yielded therapeutic agents against diseases that cannot be tackled using protein-centered approaches. Because these therapeutic agents are nucleic acid-based, they have several inherent drawbacks which include poor cellular uptake and stability. Here we report a new approach to target and degrade RNA using small molecules, proximity-induced nucleic acid degrader (PINAD). We have utilized this strategy to design two families of RNA degraders which target two different RNA structures within the genome of SARS-CoV-2: G-quadruplexes and the betacoronaviral pseudoknot. We demonstrate that these novel molecules degrade their targets using in vitro, in cellulo, and in vivo SARS-CoV-2 infection models. Our strategy allows any RNA binding small molecule to be converted into a degrader, empowering RNA binders that are not potent enough to exert a phenotypic effect on their own. PINAD raises the possibility of targeting and destroying any disease-related RNA species, which can greatly expand the space of druggable targets and diseases.info:eu-repo/semantics/publishedVersio