3,738 research outputs found
The acceleration of aging and Alzheimer’s disease through the biological mechanisms behind obesity and type II diabetes
The incidence of diabetes is predicted to increase to 21% by 2050. Currently, one third of US adults are obese and over 11% of these individuals have diabetes. Due to the growing need for therapeutic intervention to control and/or stabilize this increase in the incidence of diabetes in Western communities, gaining a comprehensive understanding of the association between obesity and Type 2 diabetes has become increasingly important to diabetes research. The increased cell senescence associated with diabetes has been associated with the limited ability of cells to divide, with indication of telomere shortening and genomic instability of the cells. Obese individuals have shorter telomeres suggesting an inverse relationship between adiposity and telomere length. The implication that Type 2 diabetes has on biological aging is of particular interest since telomere shortening in obesity and diabetes has been associated with an early risk for dementia and even progression to Alzheimer’s disease (AD). Lifestyle, nutrition and longevity are closely related and cellular senescence has been associated with telomere shortening and connected to longevity. Diet, cholesterol lowering drugs and exercise that control food intake and glucose tolerance in aging and diabetic individuals, via connections between liver circadian clocks and the suprachiasmatic nucleus in the brain, also have been shown to alter telomere lengths. Lifestyle interventions, such as diets low in fat and exercise, target the rise in obesity and associated telomere shortening by delaying or preventing the onset of Type 2 diabetes. The implementation of these anti-aging therapies early in life may prevent calorie overload and activation of calorie sensitive genes such as Sirtuin 1 (Sirt1). This may maintain telomere length and the control of obesity, which is linked to cardiovascular disease, diabetes and accelerates aging and AD
Synthesis and reactivity of N-allenyl cyanamides
N-Allenyl cyanamides have been accessed via a one-pot deoxycyanamidation–isomerization approach using propargyl alcohol and N-cyano-N-phenyl-p-methylbenzenesulfonamide. The utility of this novel class of allenamide was explored through derivatization, with hydroarylation, hydroamination, and cycloaddition protocols employed to access an array of cyanamide products that would be challenging to access using existing methods
The molecular gas kinematics in the host galaxy of non-repeating FRB 180924B
Fast radio bursts (FRBs) are millisecond-duration transients with large
dispersion measures. The origin of FRBs is still mysterious. One of the methods
to comprehend FRB origin is to probe the physical environments of FRB host
galaxies. Mapping molecular-gas kinematics in FRB host galaxies is critical
because it results in star formation that is likely connected to the birth of
FRB progenitors. However, most previous works of FRB host galaxies have focused
on its stellar component. Therefore, we, for the first time, report the
molecular gas kinematics in the host galaxy of the non-repeating FRB 180924B at
. Two velocity components of the CO (3-2) emission line are detected
in its host galaxy with the Atacama Large Millimeter/submillimeter Array
(ALMA): the peak of one component ( km s) is near the centre of
the host galaxy, and another ( km s) is near the FRB position.
The CO (3-2) spectrum shows asymmetric profiles with A , where A is the peak flux density ratio between the two
velocity components. The CO (3-2) velocity map also indicates an asymmetric
velocity gradient from km s to 8 km s. These results
indicate a disturbed kinetic structure of molecular gas in the host galaxy.
Such disturbed kinetic structures are reported for repeating FRB host galaxies
using HI emission lines in previous works. Our finding indicates that
non-repeating and repeating FRBs could commonly appear in disturbed kinetic
environments, suggesting a possible link between the gas kinematics and FRB
progenitors.Comment: 5 pages, 4 figures, Accepted for publication in MNRAS,
https://www.youtube.com/watch?v=CldxLE7Pdwk&t=1
Features of Severe Liver Disease With Portal Hypertension in Patients With Cystic Fibrosis
Liver disease is the third leading cause of death in patients with cystic fibrosis (CF), but features of patients with CF, severe liver disease, and portal hypertension have not been fully characterized
Study on Evolvement Complexity in an Artificial Stock Market
An artificial stock market is established based on multi-agent . Each agent
has a limit memory of the history of stock price, and will choose an action
according to his memory and trading strategy. The trading strategy of each
agent evolves ceaselessly as a result of self-teaching mechanism. Simulation
results exhibit that large events are frequent in the fluctuation of the stock
price generated by the present model when compared with a normal process, and
the price returns distribution is L\'{e}vy distribution in the central part
followed by an approximately exponential truncation. In addition, by defining a
variable to gauge the "evolvement complexity" of this system, we have found a
phase cross-over from simple-phase to complex-phase along with the increase of
the number of individuals, which may be a ubiquitous phenomenon in multifarious
real-life systems.Comment: 4 pages and 4 figure
Some pattern recognitions for a recommendation framework for higher education students’ generic competence development using machine learning
The project presented in this paper aims to formulate a recommendation framework that consolidates the higher education students’ particulars such as their academic background, current study and student activity records, their attended higher education institution’s expectations of graduate attributes and self-assessment of their own generic competencies. The gap between the higher education students’ generic competence development and their current statuses such as their academic performance and their student activity involvement was incorporated into the framework to come up with a recommendation for the student activities that lead to their generic competence development. For the formulation of the recommendation framework, the data mining tool Orange with some programming in Python and machine learning models was applied on 14,556 students’ activity and academic records in the case higher education institution to find out three major types of patterns between the students’ participation of the student activities and (1) their academic performance change, (2) their programmes of studies, and (3) their English results in the public examination. These findings are also discussed in this paperPeer Reviewe
Galaxy source counts at 7.7 m, 10 m and 15 m with the James Webb Space Telescope
We present mid-infrared galaxy number counts based on the Early Release
Observations obtained by the James Webb Space Telescope (JWST) at 7.7-, 10- and
15-m (F770W, F1000W and F1500W, respectively) bands of the Mid-Infrared
Instrument (MIRI). Due to the superior sensitivity of JWST, the 80 percent
completeness limits reach 0.32, 0.79 and 2.0 Jy in F770W, F1000W and
F1500W filters, respectively, i.e., 100 times deeper than previous space
infrared telescopes such as Spitzer or AKARI. The number counts reach much
deeper than the broad bump around mJy due to polycyclic aromatic
hydrocarbon (PAH) emissions. An extrapolation towards fainter flux from the
evolutionary models in the literature agrees amazingly well with the new data,
where the extrapolated faint-end of infrared luminosity functions combined with
the cosmic star-formation history to higher redshifts can reproduce the deeper
number counts by JWST. Our understanding of the faint infrared sources has been
confirmed by the observed data due to the superb sensitivity of JWST.Comment: 6 pages, 8 figures. Accepted for publication in MNRA
Health-related Quality of Life in Pediatric Patients With Chronic Hepatitis B Living in the United States and Canada
OBJECTIVES: The aim of the study was to determine whether selected sociodemographic and hepatitis B virus (HBV)-specific clinical factors are associated with health-related quality of life (HRQoL) among pediatric patients chronically infected with HBV.
METHODS: Children with chronic HBV enrolled in the Hepatitis B Research Network completed the Child Health Questionnaire at study entry. Caregivers of children 5 to <10 years completed the parent-reported form (CHQ-Parent Report Form); youth 10 to <18 years completed the child-reported CHQ-Child Report Form. We examined univariable associations of the Child Health Questionnaire scores with selected independent variables: sex, adoption status, maternal education, alanine aminotransferase (U/L), aspartate aminotransferase-to-platelet ratio index, and HBV-specific symptom count.
RESULTS: A total of 244 participants (83 young children 5-<10 years, 161 youth 10-<18 years) were included, all HBV treatment-naïve. Among young children, increased alanine aminotransferase level was negatively associated with CHQ-Parent Report Form psychosocial summary t score (r = -0.28, P = 0.01). No other subscale comparisons for young children were statistically significant. Among youth, adoption was associated with better physical functioning and general health (P < 0.01). Higher maternal education was associated with better role/functioning-physical and -emotional scores (P < 0.05). Maternal education and adoption status were linked with adoption associated with higher maternal education. Increased symptom count in youth was associated with worse HRQoL in subscales measuring bodily pain, behavior, mental health, and self-esteem (P < 0.01).
CONCLUSIONS: Although overall HRQoL is preserved in children with chronic HBV, some sociodemographic and HBV-related clinical factors were associated with impaired HRQoL in our pediatric patients at baseline. Measurement of HRQoL can focus resources on education and psychosocial support in children and families most in need
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