543 research outputs found
Some observations on the lung capacity of young people living in New Mexico
https://digitalrepository.unm.edu/unm_bulletin/1035/thumbnail.jp
MicroRNA expression is altered in an ovalbumin-induced asthma model and targeting miR-155 with antagomirs reveals cellular specificity
©2015 Plank et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source arecredited. MicroRNAs are post-transcriptional regulators of gene expression that are differentially regulated during development and in inflammatory diseases. A role for miRNAs in allergic asthma is emerging and further investigation is required to determine whether they may serve as potential therapeutic targets. We profiled miRNA expression in murine lungs from an ovalbumin-induced allergic airways disease model, and compared expression to animals receiving dexamethasone treatment and non-allergic controls. Our analysis identified 29 miRNAs that were significantly altered during allergic inflammation. Target prediction analysis revealed novel genes with altered expression in allergic airways disease and suggests synergistic miRNA regulation of target mRNAs. To assess the impacts of one induced miRNA on pathology, we targeted miR-155-5p using a specific antagomir. Antagomir administration successfully reduced miR-155-5p expression with high specificity, but failed to alter the disease phenotype. Interestingly, further investigation revealed that antagomir delivery has variable efficacy across different immune cell types, effectively targeting myeloid cell populations, but exhibiting poor uptake in lymphocytes. Our findings demonstrate that antagomir-based targeting of miRNA function in the lung is highly specific, but highlights cell-specificity as a key limitation to be considered for antagomir-based strategies as therapeutics
NLTE determination of the sodium abundance in a homogeneous sample of extremely metal-poor stars
Abundance ratios in extremely metal-poor (EMP) stars are a good indication of
the chemical composition of the gas in the earliest phases of the Galaxy
evolution. It had been found from an LTE analysis that at low metallicity, and
in contrast with most of the other elements, the scatter of [Na/Fe] versus
[Fe/H] was surprisingly large and that, in giants, [Na/Fe] decreased with
metallicity.
Since it is well known that the formation of sodium lines is very sensitive
to non-LTE effects, to firmly establish the behaviour of the sodium abundance
in the early Galaxy, we have used high quality observations of a sample of EMP
stars obtained with UVES at the VLT, and we have taken into account the non-LTE
line formation of sodium.
The profiles of the two resonant sodium D lines (only these sodium lines are
detectable in the spectra of EMP stars) have been computed in a sample of 54
EMP giants and turn-off stars (33 of them with [Fe/H]< -3.0) with a modified
version of the code MULTI, and compared to the observed spectra.
With these new determinations in the range -4 <[Fe/H]< -2.5, both [Na/Fe] and
[Na/Mg] are almost constant with a low scatter. In the turn-off stars and
"unmixed" giants (located in the low RGB): [Na/Fe] = -0.21 +/- 0.13 or [Na/Mg]
= -0.45 +/- 0.16. These values are in good agreement with the recent
determinations of [Na/Fe] and [Na/Mg] in nearby metal-poor stars. Moreover we
confirm that all the sodium-rich stars are "mixed" stars (i.e., giants located
after the bump, which have undergone an extra mixing). None of the turn-off
stars is sodium-rich. As a consequence it is probable that the sodium
enhancement observed in some mixed giants is the result of a deep mixing.Comment: 8 pages, 9 figures; accepted for publication in A&
On the Formation Height of the SDO/HMI Fe 6173 Doppler Signal
The Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics
Observatory (SDO) is designed to study oscillations and the mag- netic field in
the solar photosphere. It observes the full solar disk in the Fe I absorption
line at 6173\AA . We use the output of a high-resolution 3D, time- dependent,
radiation-hydrodynamic simulation based on the CO5BOLD code to calculate
profiles F({\lambda},x,y,t) for the Fe I 6173{\AA} line. The emerging profiles
F({\lambda},x,y,t) are multiplied by a representative set of HMI filter
transmission profiles R_i({\lambda},1 \leq i \leq 6) and filtergrams
I_i(x,y,t;1 \leq i \leq 6) are constructed for six wavelengths. Doppler
velocities V_HMI(x,y,t) are determined from these filtergrams using a
simplified version of the HMI pipeline. The Doppler velocities are correlated
with the original velocities in the simulated atmosphere. The cross-
correlation peaks near 100 km, suggesting that the HMI Doppler velocity signal
is formed rather low in the solar atmosphere. The same analysis is performed
for the SOHO/MDI Ni I line at 6768\AA . The MDI Doppler signal is formed
slightly higher at around 125 km. Taking into account the limited spatial
resolution of the instruments, the apparent formation height of both the HMI
and MDI Doppler signal increases by 40 to 50 km. We also study how
uncertainties in the HMI filter-transmission profiles affect the calculated
velocities.Comment: 15 pages, 11 Figure
NLTE determination of the aluminium abundance in a homogeneous sample of extremely metal-poor stars
Aims: Aluminium is a key element to constrain the models of the chemical
enrichment and the yields of the first supernovae. But obtaining precise Al
abundances in extremely metal-poor (EMP) stars requires that the non-LTE
effects be carefully taken into account.
Methods: The NLTE profiles of the blue resonance aluminium lines have been
computed in a sample of 53 extremely metal-poor stars with a modified version
of the program MULTI applied to an atomic model of the Al atom with 78 levels
of Al I and 13 levels of Al II, and compared to the observations.
Results: With these new determinations, all the stars of the sample show a
ratio Al/Fe close to the solar value: [Al/Fe] =-0.06 +- 0.10 with a very small
scatter. These results are compared to the models of the chemical evolution of
the halo using different models of SN II and are compatible with recent
computations. The sodium-rich giants are not found to be also aluminium-rich
and thus, as expected, the convection in these giants only brings to the
surface the products of the Ne-Na cycle.Comment: To be published on A&
Radiative emission of solar features in the Ca II K line: comparison of measurements and models
We study the radiative emission of various types of solar features, such as
quiet Sun, enhanced network, plage, and bright plage regions, identified on
filtergrams taken in the Ca II K line. We analysed fulldisk images obtained
with the PSPT, by using three interference filters that sample the Ca II K line
with different bandpasses. We studied the dependence of the radiative emission
of disk features on the filter bandpass. We also performed a NLTE spectral
synthesis of the Ca II K line integrated over the bandpass of PSPT filters. The
synthesis was carried out by utilizing both the PRD and CRD with the most
recent set of semi empirical atmosphere models in the literature and some
earlier atmosphere models. We measured the CLV of intensity values for various
solar features identified on PSPT images and compared the results obtained with
those derived from the synthesis. We find that CRD calculations derived using
the most recent quiet Sun model, on average, reproduce the measured values of
the quiet Sun regions slightly more accurately than PRD computations with the
same model. This may reflect that the utilized atmospheric model was computed
assuming CRD. Calculations with PRD on earlier quiet Sun model atmospheres
reproduce measured quantities with a similar accuracy as to that achieved here
by applying CRD to the recent model. We also find that the median contrast
values measured for most of the identified bright features, disk positions, and
filter widths are, on average, a factor 1.9 lower than those derived from PRD
simulations performed using the recent bright feature models. The discrepancy
between measured and modeled values decreases by 12% after taking into account
straylight effects on PSPT images. PRD computations on either the most recent
or the earlier atmosphere models of bright features reproduce measurements from
plage and bright plage regions with a similar accuracy.Comment: 14 pages, 18 figures, accepted by A&
Developing autonomous learning in first year university students using perspectives from positive psychology
Autonomous learning is a commonly occurring learning outcome from university study, and it is argued that students require confidence in their own abilities to achieve this. Using approaches from positive psychology, this study aimed to develop confidence in first‐year university students to facilitate autonomous learning. Psychological character strengths were assessed in 214 students on day one at university. Two weeks later their top three strengths were given to them in study skills modules as part of a psycho‐educational intervention designed to increase their self‐efficacy and self‐esteem. The impact of the intervention was assessed against a control group of 40 students who had not received the intervention. The results suggested that students were more confident after the intervention, and that levels of autonomous learning increased significantly compared to the controls. Character strengths were found to be associated with self‐efficacy, self‐esteem and autonomous learning in ways that were theoretically meaningful
Determinants of pre-vaccination antibody responses to SARS-CoV-2: a population-based longitudinal study (COVIDENCE UK)
BACKGROUND: Prospective population-based studies investigating multiple determinants of pre-vaccination antibody responses to SARS-CoV-2 are lacking. METHODS: We did a prospective population-based study in SARS-CoV-2 vaccine-naive UK adults recruited between May 1 and November 2, 2020, without a positive swab test result for SARS-CoV-2 prior to enrolment. Information on 88 potential sociodemographic, behavioural, nutritional, clinical and pharmacological risk factors was obtained through online questionnaires, and combined IgG/IgA/IgM responses to SARS-CoV-2 spike glycoprotein were determined in dried blood spots obtained between November 6, 2020, and April 18, 2021. We used logistic and linear regression to estimate adjusted odds ratios (aORs) and adjusted geometric mean ratios (aGMRs) for potential determinants of SARS-CoV-2 seropositivity (all participants) and antibody titres (seropositive participants only), respectively. RESULTS: Of 11,130 participants, 1696 (15.2%) were seropositive. Factors independently associated with higher risk of SARS-CoV-2 seropositivity included frontline health/care occupation (aOR 1.86, 95% CI 1.48–2.33), international travel (1.20, 1.07–1.35), number of visits to shops and other indoor public places (≥ 5 vs. 0/week: 1.29, 1.06–1.57, P-trend = 0.01), body mass index (BMI) ≥ 25 vs. < 25 kg/m(2) (1.24, 1.11–1.39), South Asian vs. White ethnicity (1.65, 1.10–2.49) and alcohol consumption ≥15 vs. 0 units/week (1.23, 1.04–1.46). Light physical exercise associated with lower risk (0.80, 0.70–0.93, for ≥ 10 vs. 0–4 h/week). Among seropositive participants, higher titres of anti-Spike antibodies associated with factors including BMI ≥ 30 vs. < 25 kg/m(2) (aGMR 1.10, 1.02–1.19), South Asian vs. White ethnicity (1.22, 1.04–1.44), frontline health/care occupation (1.24, 95% CI 1.11–1.39), international travel (1.11, 1.05–1.16) and number of visits to shops and other indoor public places (≥ 5 vs. 0/week: 1.12, 1.02–1.23, P-trend = 0.01); these associations were not substantially attenuated by adjustment for COVID-19 disease severity. CONCLUSIONS: Higher alcohol consumption and lower light physical exercise represent new modifiable risk factors for SARS-CoV-2 infection. Recognised associations between South Asian ethnic origin and obesity and higher risk of SARS-CoV-2 seropositivity were independent of other sociodemographic, behavioural, nutritional, clinical, and pharmacological factors investigated. Among seropositive participants, higher titres of anti-Spike antibodies in people of South Asian ancestry and in obese people were not explained by greater COVID-19 disease severity in these groups. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12916-022-02286-4
The novel mu-opioid antagonist, GSK1521498, reduces ethanol consumption in C57BL/6J mice.
RATIONALE
Using the drinking-in-the-dark (DID) model, we compared the effects of a novel mu-opioid receptor antagonist, GSK1521498, with naltrexone, a licensed treatment of alcohol dependence, on ethanol consumption in mice.
OBJECTIVE
We test the ability of GSK1521498 to reduce alcohol consumption and compare its intrinsic efficacy to that of naltrexone by comparing the two drugs at doses matched for equivalent receptor occupancy.
METHODS
Thirty-six C57BL/6J mice were tested in a DID procedure. In 2-day cycles, animals experienced one baseline, injection-free session, and one test session when they received two injections, one of test drug and one placebo. All animals received GSK1521498 (0, 0.1, 1 and 3 mg/kg, i.p., 30 min pre-treatment) and naltrexone (0, 0.1, 1 and 3 mg/kg, s.c. 10 min pre-treatment) in a cross-over design. Receptor occupancies following the same doses were determined ex vivo in separate groups by autoradiography, using [3H]DAMGO. Binding in the region of interest was measured integrally by computer-assisted microdensitometry and corrected for non-specific binding.
RESULTS
Both GSK1521498 and naltrexone dose-dependently decreased ethanol consumption. When drug doses were matched for 70-75 % receptor occupancy, GSK1521498 3 mg/kg, i.p., caused a 2.5-fold greater reduction in alcohol consumption than naltrexone 0.1 mg/kg, s.c. Both GSK1521498 and naltrexone significantly reduced sucrose consumption at a dose of 1 mg/kg but not 0.1 mg/kg. In a test of conditioned taste aversion, GSK1521498 (3 mg/kg) reduced sucrose consumption 24 h following exposure to a conditioning injection.
CONCLUSIONS
Both opioid receptor antagonists reduced alcohol consumption but GK1521498 has higher intrinsic efficacy than naltrexone
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