358 research outputs found
A Spectroscopic Redshift Measurement for a Luminous Lyman Break Galaxy at z=7.730 using Keck/MOSFIRE
We present a spectroscopic redshift measurement of a very bright Lyman break
galaxy at z=7.7302+-0.0006 using Keck/MOSFIRE. The source was pre-selected
photometrically in the EGS field as a robust z~8 candidate with H=25.0 mag
based on optical non-detections and a very red Spitzer/IRAC [3.6]-[4.5]
broad-band color driven by high equivalent width [OIII]+Hbeta line emission.
The Lyalpha line is reliably detected at 6.1 sigma and shows an asymmetric
profile as expected for a galaxy embedded in a relatively neutral
inter-galactic medium near the Planck peak of cosmic reionization. The line has
a rest-frame equivalent width of EW0=21+-4 A and is extended with
V_FWHM=360+90-70 km/s. The source is perhaps the brightest and most massive z~8
Lyman break galaxy in the full CANDELS and BoRG/HIPPIES surveys, having
assembled already 10^(9.9+-0.2) M_sol of stars at only 650 Myr after the Big
Bang. The spectroscopic redshift measurement sets a new redshift record for
galaxies. This enables reliable constraints on the stellar mass, star-formation
rate, formation epoch, as well as combined [OIII]+Hbeta line equivalent widths.
The redshift confirms that the IRAC [4.5] photometry is very likely dominated
by line emission with EW0(OIII+Hbeta)= 720-150+180 A. This detection thus adds
to the evidence that extreme rest-frame optical emission lines are a ubiquitous
feature of early galaxies promising very efficient spectroscopic follow-up in
the future with infrared spectroscopy using JWST and, later, ELTs.Comment: 6 pages, 4 figures, small updates to match ApJL accepted versio
Properties of recombinant human cytosolic sialidase HsNEU2. The enzyme hydrolyzes monomerically dispersed GM1 ganglioside molecules
Recombinant human cytosolic sialidase (HsNEU2), expressed in Escherichia coli, was purified to homogeneity, and its substrate specificity was studied. HsNEU2 hydrolyzed 4-methylumbelliferyl alpha-NeuAc, alpha 2-->3 sialyllactose, glycoproteins (fetuin, alpha-acid glycoprotein, transferrin, and bovine submaxillary gland mucin), micellar gangliosides GD1a, GD1b, GT1b, and alpha 2-->3 paragloboside, and vesicular GM3. alpha 2-->6 sialyllactose, colominic acid, GM1 oligosaccharide, whereas micellar GM2 and GM1 were resistant. The optimal pH was 5.6, kinetics Michaelis-Menten type, V(max) varying from 250 IU/mg protein (GD1a) to 0.7 IU/mg protein (alpha(1)-acid glycoprotein), and K(m) in the millimolar range. HsNEU2 was activated by detergents (Triton X-100) only with gangliosidic substrates; the change of GM3 from vesicular to mixed micellar aggregation led to a 8.5-fold V(max) increase. HsNEU2 acted on gangliosides (GD1a, GM1, and GM2) at nanomolar concentrations. With these dispersions (studied in detailed on GM1), where monomers are bound to the tube wall or dilutedly associated (1:2000, mol/mol) to Triton X-100 micelles, the V(max) values were 25 and 72 microIU/mg protein, and K(m) was 10 and 15 x 10(-9) m, respectively. Remarkably, GM1 and GM2 were recognized only as monomers. HsNEU2 worked at pH 7.0 with an efficiency (compared with that at pH 5.6) ranging from 4% (on GD1a) to 64% (on alpha(1)-acid glycoprotein), from 7% (on GD1a) to 45% (on GM3) in the presence of Triton X-100, and from 30 to 40% on GM1 monomeric dispersion. These results show that HsNEU2 differentially recognizes the type of sialosyl linkage, the aglycone part of the substrate, and the supramolecular organization (monomer/micelle/vesicle) of gangliosides. The last ability might be relevant in sialidase interactions with gangliosides under physiological conditions
Peripheral Purinergic Modulation in Pediatric Orofacial Inflammatory Pain Affects Brainstem Nitroxidergic System: A Translational Research
Physiology of orofacial pain pathways embraces primary afferent neurons, pathologic changes in the trigeminal ganglion, brainstem nociceptive neurons, and higher brain function regulating orofacial nociception. The goal of this study was to investigate the nitroxidergic system alteration at brainstem level (spinal trigeminal nucleus), and the role of peripheral P2 purinergic receptors in an experimental mouse model of pediatric inflammatory orofacial pain, to increase knowledge and supply information concerning orofacial pain in children and adolescents, like pediatric dentists and pathologists, as well as oro-maxillo-facial surgeons, may be asked to participate in the treatment of these patients. The experimental animals were treated subcutaneously in the perioral region with pyridoxalphosphate-6-azophenyl-2âČ,4âČ-disulphonic acid (PPADS), a P2 receptor antagonist, 30 minutes before formalin injection. The pain-related behavior and the nitroxidergic system alterations in the spinal trigeminal nucleus using immunohistochemistry and western blotting analysis have been evaluated. The local administration of PPADS decreased the face-rubbing activity and the expression of both neuronal and inducible nitric oxide (NO) synthase isoforms in the spinal trigeminal nucleus. These results underline a relationship between orofacial inflammatory pain and nitroxidergic system in the spinal trigeminal nucleus and suggest a role of peripheral P2 receptors in trigeminal pain transmission influencing NO production at central level. In this way, orofacial pain physiology should be elucidated and applied to clinical practice in the future
Nutrition in Pediatric Inflammatory Bowel Disease: From Etiology to Treatment : A Systematic Review
Nutrition is involved in several aspects of pediatric inflammatory bowel disease (IBD), ranging from disease etiology to induction and maintenance of disease. With regards to etiology, there are pediatric data, mainly from case-control studies, which suggest that some dietary habits (for example consumption of animal protein, fatty foods, high sugar intake) may predispose patients to IBD onset. As for disease treatment, exclusive enteral nutrition (EEN) is an extensively studied, well established, and valid approach to the remission of pediatric Crohn's disease (CD). Apart from EEN, several new nutritional approaches are emerging and have proved to be successful (specific carbohydrate diet and CD exclusion diet) but the available evidence is not strong enough to recommend this kind of intervention in clinical practice and new large experimental controlled studies are needed, especially in the pediatric population. Moreover, efforts are being made to identify foods with anti-inflammatory properties such as curcumin and long-chain polyunsaturated fatty acids n-3, which can possibly be effective in maintenance of disease. The present systematic review aims at reviewing the scientific literature on all aspects of nutrition in pediatric IBD, including the most recent advances on nutritional therapy
Small RNA Profile in Moso Bamboo Root and Leaf Obtained by High Definition Adapters
Moso bamboo (Phyllostachy heterocycla cv. pubescens L.) is an economically important fast-growing tree. In order to gain better understanding of gene expression regulation in this important species we used next generation sequencing to profile small RNAs in leaf and roots of young seedlings. Since standard kits to produce cDNA of small RNAs are biased for certain small RNAs, we used High Definition adapters that reduce ligation bias. We identified and experimentally validated five new microRNAs and a few other small non-coding RNAs that were not microRNAs. The biological implication of microRNA expression levels and targets of microRNAs are discussed
Centrally concentrated molecular gas driving galactic-scale ionized gas outflows in star-forming galaxies
We perform a joint analysis of high spatial resolution molecular gas and star-formation rate (SFR) maps in main-sequence star-forming galaxies experiencing galactic-scale outflows of ionized gas. Our aim is to understand the mechanism that determines which galaxies are able to launch these intense winds. We observed CO(1â0) at 1-arcsec resolution with ALMA in 16 edge-on galaxies, which also have 2-arcsec spatial-resolution optical integral field observations from the SAMI Galaxy Survey. Half the galaxies in the sample were previously identified as harbouring intense and large-scale outflows of ionized gas (âoutflow typesâ) and the rest serve as control galaxies. The data set is complemented by integrated CO(1â0) observations from the IRAM 30-m telescope to probe the total molecular gas reservoirs. We find that the galaxies powering outflows do not possess significantly different global gas fractions or star-formation efficiencies when compared with a control sample. However, the ALMA maps reveal that the molecular gas in the outflow-type galaxies is distributed more centrally than in the control galaxies. For our outflow-type objects, molecular gas and star-formation are largely confined within their inner effective radius (reff), whereas in the control sample, the distribution is more diffuse, extending far beyond reff. We infer that outflows in normal star-forming galaxies may be caused by dynamical mechanisms that drive molecular gas into their central regions, which can result in locally enhanced gas surface density and star-formation
The association between a body shape index and cardiovascular risk in overweight and obese children and adolescents
A Body Shape Index (ABSI) and normalized hip circumference (Hip Index, HI) have been recently shown to be strong risk factors for mortality and for cardiovascular disease in adults. We conducted an observational cross-sectional study to evaluate the relationship between ABSI, HI and cardiometabolic risk factors and obesity-related comorbidities in overweight and obese children and adolescents aged 2\u201318 years. We performed multivariate linear and logistic regression analyses with BMI, ABSI, and HI age and sex normalized z scores as predictors to examine the association with cardiometabolic risk markers (systolic and diastolic blood pressure, fasting glucose and insulin, total cholesterol and its components, transaminases, fat mass % detected by bioelectrical impedance analysis) and obesity-related conditions (including hepatic steatosis and metabolic syndrome). We recruited 217 patients (114 males), mean age 11.3 years. Multivariate linear regression showed a significant association of ABSI z score with 10 out of 15 risk markers expressed as continuous variables, while BMI z score showed a significant correlation with 9 and HI only with 1. In multivariate logistic regression to predict occurrence of obesity-related conditions and above-threshold values of risk factors, BMI z score was significantly correlated to 7 out of 12, ABSI to 5, and HI to 1. Overall, ABSI is an independent anthropometric index that was significantly associated with cardiometabolic risk markers in a pediatric population affected by overweight and obesity
Effects of a multidisciplinary weight loss intervention in overweight and obese children and adolescents: 11 years of experience
Aims To evaluate the effects of an outpatient multidisciplinary weight loss intervention in reducing body mass index (BMI) in children and adolescents suffering overweight and obesity, changes in A Body Shape Index (ABSI, waist circumference normalized to height and weight) and Hip Index (HI, normalized hip circumference) during treatment and correlation between the ABSI and HI with change in BMI z score. Methods We analyze anthropometric data from pediatric patients affected by overweight and obesity aged 2 to 18 years old who entered our multidisciplinary weight loss intervention, which included medical, psychological and nutritional sessions, from January 1st 2006 to December 31st 2016. Lifestyle modification counselling was delivered. Follow-up visits were planned every month for 3 months and subsequently every 2'4 months. BMI, ABSI, and HI were converted to z scores using age and sex specific population normals. Results 864 patients entered our intervention. 453 patients (208 males), mean age 11.2 \uc2\ub13.1 years, 392 with obesity (86%, z-BMI 2.90 \uc2\ub10.80 SD) and 61 patients with overweight (z-BMI 1.73\uc2\ub10.21 SD) attended at least 1 follow-up visit. The mean number of visits was 3.5 (\uc2\ub1 1.8 SD) in overweight subjects and 3.9 (\uc2\ub12.2 SD) in ones with obesity. At the last attended follow-up visit (at 16 \uc2\ub1 12 months SD) we observed a reduction in mean z-BMI in patients with obesity (to 2.52 \uc2\ub10.71 SD) and patients with overweight (to 1.46 \uc2\ub10.5 SD). Most patients (80.8%) reduced their BMI z scores. Mean ABSI and HI z scores showed no significant change. 78/392 patients (19.8%) recovered from obese to overweight, 5/392 (1.2%) from obese to normal weight. The recovery rate from overweight to normal weight was 13.1%. In a multivariate model, initial BMI z score and number of follow-up visits were significant predictors of weight change, while age, sex, ABSI, and HI were not significant predictors. Conclusions Patients affected by overweight and obesity involved in a multidisciplinary weight loss intervention reduced their mean BMI z score, while ABSI and HI were stable. Weight loss was not predicted by initial ABSI or HI. More visits predict more weight loss, but dropout rates are high. The great majority of patients leave the weight management program before having normalized their BMI
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