23 research outputs found
Spatially-resolved spectroscopy of narrow-line Seyfert 1 host galaxies
We present optical integral field spectroscopy for five narrow-line
Seyfert 1 galaxies (NLS1s) host galaxies, probing their host galaxies at
kpc scales. Emission lines in the nuclear AGN spectra and the
large-scale host galaxy are analyzed separately, based on an AGN-host
decomposition technique. The host galaxy gas kinematics indicates large-scale
gas rotation in all five sources. At the probed scales of kpc,
the host galaxy gas is found to be predominantly ionized by star formation
without any evidence of a strong AGN contribution. None of the five objects
shows specific star formation rates exceeding the main sequence of low-redshift
star forming galaxies. The specific star formation rates for MCG-05-01-013 and
WPVS 007 are roughly consistent with the main sequence, while ESO 399-IG20, MS
22549-3712, and TON S180 show lower specific star formation rates, intermediate
to the main sequence and red quiescent galaxies. The host galaxy metallicities,
derived for the two sources with sufficient data quality (ESO 399-IG20 and
MCG-05-01-013), indicate central oxygen abundances just below the low-redshift
mass-metallicity relation. Based on this initial case study, we outline a
comparison of AGN and host galaxy parameters as a starting point for future
extended NLS1 studies with similar methods.Comment: 25 pages, 8 figures, accepted for publication in ApJ on 3 September
201
Effects of meal timing on changes in circulating epinephrine, norepinephrine, and acylated ghrelin concentrations: A pilot study
Abstract Background Timing of food intake impacts on metabolic diseases. Few data are available about post-meal changes in epinephrine (E), norepinephrine (NE), and acylated ghrelin (AG) at different times of the day. Subjects and methods This randomized cross-over trial investigated E/NE/AG concentrations after identical meals consumed at 0800 or 2000 hours in 20 healthy volunteers, by standardizing diet, exercise, duration of fast, and resting. Participants randomly received the test meal at 0800 or 2000 hours, and vice versa after 1 week. Blood samples were collected before and up to 180-min post-meal, every 30 min, with participants supine, motionless, but awake. Results Median E levels increased at 30–60 min, then declined and rose again at 150 min; values at 60 min (19.0 vs. 15.0 ng/l, p = 0.03) and 180 min (25.0 vs. 11.0 ng/l, p < 0.001) were higher after the morning meals. NE rose at 30–60 min and then progressively declined; median values at 60 min (235.3 vs. 206.3 ng/l, p = 0.02) and 120 min (208.8 vs. 142.0 ng/l, p = 0.04) increased more after morning meals. AG progressively declined to increase again at 90 min after meal; median AG area-under-the-curve (AUC) values were lower at morning (7206.8 vs. 8828.3 pg/mL×h). AG-AUC was inversely associated with diet-induced thermogenesis (β = −121.6; 95% CI −201.0 to 42.2; p = 0.009 for each unit increase), while log NE-AUC was inversely associated with log-triglyceride AUC (β = −0.57; 95% CI −0.98 to 0.16; p = 0.015) in a multiple regression model, after multiple adjustments. Conclusions In conclusion, E/NE concentrations were higher after the morning meal, while AG showed an opposite behavior. These data, although requiring confirmation in larger samples, suggest an adjunctive possible mechanism explaining the unfavorable effects of evening eating on metabolic ris
Role of Diet in Stem and Cancer Stem Cells
Diet and lifestyle factors greatly affect health and susceptibility to diseases, including cancer. Stem cells’ functions, including their ability to divide asymmetrically, set the rules for tissue homeostasis, contribute to health maintenance, and represent the entry point of cancer occurrence. Stem cell properties result from the complex integration of intrinsic, extrinsic, and systemic factors. In this context, diet-induced metabolic changes can have a profound impact on stem cell fate determination, lineage specification and differentiation. The purpose of this review is to provide a comprehensive description of the multiple “non-metabolic” effects of diet on stem cell functions, including little-known effects such as those on liquid-liquid phase separation and on non-random chromosome segregation (asymmetric division). A deep understanding of the specific dietetic requirements of normal and cancer stem cells may pave the way for the development of nutrition-based targeted therapeutic approaches to improve regenerative and anticancer therapies
Predictable and unpredictable deviance detection in the human hippocampus and amygdala
Our brains extract structure from the environment and form predictions given past experience. Predictive circuits have been identified in wide-spread cortical regions. However, the contribution of medial temporal structures in predictions remains under-explored. The hippocampus underlies sequence detection and is sensitive to novel stimuli, sufficient to gain access to memory, while the amygdala to novelty. Yet, their electrophysiological profiles in detecting predictable and unpredictable deviant auditory events remain unknown. Here, we hypothesized that the hippocampus would be sensitive to predictability, while the amygdala to unexpected deviance. We presented epileptic patients undergoing presurgical monitoring with standard and deviant sounds, in predictable or unpredictable contexts. Onsets of auditory responses and unpredictable deviance effects were detected earlier in the temporal cortex compared with the amygdala and hippocampus. Deviance effects in 1-20 Hz local field potentials were detected in the lateral temporal cortex, irrespective of predictability. The amygdala showed stronger deviance in the unpredictable context. Low-frequency deviance responses in the hippocampus (1-8 Hz) were observed in the predictable but not in the unpredictable context. Our results reveal a distributed network underlying the generation of auditory predictions and suggest that the neural basis of sensory predictions and prediction error signals needs to be extended
Predictable and unpredictable deviance detection in the human hippocampus and amygdala.
Our brains extract structure from the environment and form predictions given past experience. Predictive circuits have been identified in wide-spread cortical regions. However, the contribution of medial temporal structures in predictions remains under-explored. The hippocampus underlies sequence detection and is sensitive to novel stimuli, sufficient to gain access to memory, while the amygdala to novelty. Yet, their electrophysiological profiles in detecting predictable and unpredictable deviant auditory events remain unknown. Here, we hypothesized that the hippocampus would be sensitive to predictability, while the amygdala to unexpected deviance. We presented epileptic patients undergoing presurgical monitoring with standard and deviant sounds, in predictable or unpredictable contexts. Onsets of auditory responses and unpredictable deviance effects were detected earlier in the temporal cortex compared with the amygdala and hippocampus. Deviance effects in 1-20 Hz local field potentials were detected in the lateral temporal cortex, irrespective of predictability. The amygdala showed stronger deviance in the unpredictable context. Low-frequency deviance responses in the hippocampus (1-8 Hz) were observed in the predictable but not in the unpredictable context. Our results reveal a distributed network underlying the generation of auditory predictions and suggest that the neural basis of sensory predictions and prediction error signals needs to be extended
Diet-Gut Microbiota Interactions and Gestational Diabetes Mellitus (GDM)
Medical nutritional therapy is the first-line approach in managing gestational diabetes mellitus (GDM). Diet is also a powerful modulator of the gut microbiota, whose impact on insulin resistance and the inflammatory response in the host are well known. Changes in the gut microbiota composition have been described in pregnancies either before the onset of GDM or after its diagnosis. The possible modulation of the gut microbiota by dietary interventions in pregnancy is a topic of emerging interest, in consideration of the potential effects on maternal and consequently neonatal health. To date, very few data from observational studies are available about the associations between diet and the gut microbiota in pregnancy complicated by GDM. In this review, we analyzed the available data and discussed the current knowledge about diet manipulation in order to shape the gut microbiota in pregnancy
Consuming more of daily caloric intake at dinner predisposes to obesity. A 6-year population-based prospective cohort study.
It has been hypothesized that assuming most of the caloric intake later in the day leads to metabolic disadvantages, but few studies are available on this topic. Aim of our study was to prospectively examine whether eating more of the daily caloric intake at dinner leads to an increased risk of obesity, hyperglycemia, metabolic syndrome, and non-alcoholic fatty liver disease (NAFLD).1245 non-obese, non-diabetic middle-aged adults from a population-based cohort underwent a 3-day food record questionnaire at enrollment. Anthropometric values, blood pressure, blood metabolic variables, and estimated liver fat were measured at baseline and at 6-year follow-up.Prospective cohort study.Subjects were divided according to tertiles of percent daily caloric intake at dinner. A significant increase in the incidence rate of obesity (from 4.7 to 11.4%), metabolic syndrome (from 11.1 to 16.1%), and estimated NAFLD (from 16.5 to 23.8%) was observed from the lower to higher tertile. In a multiple logistic regression model adjusted for multiple covariates, subjects in the highest tertile showed an increased risk of developing obesity (OR = 2.33; 95% CI 1.17-4.65; p = 0.02), metabolic syndrome (OR = 1.52; 95% CI 1.01-2.30; p = 0.04), and NAFLD (OR = 1.56; 95% CI 1.10-2.22; p = 0.01).Consuming more of the daily energy intake at dinner is associated with an increased risk of obesity, metabolic syndrome, and NAFLD