808,478 research outputs found
Cyclosporin A inhibits PGE2 release from vascular smooth muscle cells
The influence of the fungoid undecapeptide cyclosporin A (CyA) on PGE2 release from cultured rat aortic smooth muscle cells was investigated in this study. We found that CyA time and concentration dependently (ED50:500 ng/ml) inhibited PGE2 release from the cells. CyA attenuated both basal and PGE2 release evoked by angiotensin II (10(-10)-10(-6) M), arginine vasopressin (10(-10)-10(-6) M) and ionomycin (10(-9)-10(-6) M). CyA (1 microgram/ml) did not affect the conversion of exogenous arachidonic acid (1 microM) into PGE2. The inhibitory effect of CyA was neutralized by high concentrations of the calcium ionophore ionomycin (greater than 3 X 10(-6) M). Taken together our results indicate that CyA inhibits both basal and vasoconstrictor evoked PGE2 release from vascular smooth muscle by impairing the availability of free arachidonic acid rather than by inhibiting the conversion of arachidonic acid into PGE2
Detection of an intergalactic meteor particle with the 6-m telescope
On July 28, 2006 the 6-m telescope of the Special Astrophysical Observatory
of the Russian Academy of Sciences recorded the spectrum of a faint meteor. We
confidently identify the lines of FeI and MgI, OI, NI and molecular-nitrogen
N_2 bands. The entry velocity of the meteor body into the Earth's atmosphere
estimated from radial velocity is equal to 300 km/s. The body was several tens
of a millimeter in size, like chondrules in carbon chondrites. The radiant of
the meteor trajectory coincides with the sky position of the apex of the motion
of the Solar system toward the centroid of the Local Group of galaxies.
Observations of faint sporadic meteors with FAVOR TV CCD camera confirmed the
radiant at a higher than 96% confidence level. We conclude that this meteor
particle is likely to be of extragalactic origin. The following important
questions remain open: (1) How metal-rich dust particles came to be in the
extragalactic space? (2) Why are the sizes of extragalactic particles larger by
two orders of magnitude (and their masses greater by six orders of magnitude)
than common interstellar dust grains in our Galaxy? (3) If extragalactic dust
surrounds galaxies in the form of dust (or gas-and-dust) aureoles, can such
formations now be observed using other observational techniques (IR
observations aboard Spitzer satellite, etc.)? (4) If inhomogeneous
extragalactic dust medium with the parameters mentioned above actually exists,
does it show up in the form of irregularities on the cosmic microwave
background (WMAP etc.)?Comment: 9 pages, 6 EPS figure
Quantifying the vertical fusion range at four distances of fixation in a normal population.
Aim: To compare the vertical fusional amplitudes in
isometropic participants with normal binocular
single vision at four distances of fixation: 33 cm,
1 m, 4 m, 6 m.
Methods: Vertical fusion ranges (break point and
recovery point) were measured with a Gulden
vertical prism bar with the participant fixing a 6/12
Snellen equivalent letter, twice at each distance.
Order effects were controlled with randomisation of
both fixation distance and prism direction.
Results: Twenty-seven participants were examined
(aged 20.4 ± 1.05 years). Base up and base down
measurements were similar, therefore measurements
were combined to give a total vertical range. Median
values for the break points were: 33 cm, 6(Δ) ; 1 m, 6(Δ);
4 m, 5.5(Δ); 6 m, 5.5(Δ); and for the recovery points were:
33 cm, 4(Δ); 1 m, 4(Δ); 4 m, 3.5(Δ); 6 m, 3.5(Δ). The
difference was significant between either of the near
measures (i.e. 33 cm and 1 m) and either of the far
measures (i.e. 4 m and 6 m).
Conclusions: The vertical fusion range appears to be
slightly greater at near than distance. However, the
difference is not clinically significant. Measurements
for distance, in a normal population, appear to be the
same whether a fixation distance of 4 m or 6 m is
used
The earliest spectroscopy of the GRB 030329 afterglow with 6-m telescope
The earliest BTA (SAO RAS 6-m telescope) spectroscopic observations of the
GRB 030329 optical transient (OT) are presented, which almost coincide in time
with the "first break" ( day after the GRB) of the OT light curve.
The beginning of spectral changes are seen as early as hours after
the GRB. So, the onset of the spectral changes for day indicates that the
contribution from Type Ic supernova (SN) into the OT optical flux can be
detected earlier. The properties of early spectra of GRB 030329/SN 2003dh can
be consistent with a shock moving into a stellar wind formed from the pre-SN.
Such a behavior (similar to that near the UV shock breakout in SNe) can be
explained by the existence of a dense matter in the immediate surroundings of
massive stellar GRB/SN progenitor). The urgency is emphasized of observation of
early GRB/SN spectra for solving a question that is essential for understanding
GRB physical mechanism: {\it Do all} long-duration gamma-ray bursts are caused
by (or physically connected to) {\it ordinary} core-collapse supernovae? If
clear association of normal/ordinary core-collapse SNe (SN Ib/c, and others SN
types) and GRBs would be revealed in numbers of cases, we may have strong
observational limits for gamma-ray beaming and for real energetics of the GRB
sources.Comment: 4 pages, 5 figures. Proceedings of the 4th Workshop "Gamma-Ray Bursts
in the Afterglow Era", Roma, 2004 October 18-22, eds. L. Piro, L. Amati, S.
Covino, and B. Gendre. Il Nuovo Cimento, in pres
A Metabolically Healthy Profile Is a Transient Stage When Exercise and Diet Are Not Supervised: Long-Term Effects in the EXERDIET-HTA Study
Metabolically unhealthy obesity (MUO) is a regular state in people with primary hypertension (HTN), obesity, and who are physically inactive. To achieve and maintain a metabolically healthy overweight/obese (MHO) state should be a main treatment goal. The aims of the study were (1) to determine differences in metabolic profiles of overweight/obese, physically inactive individuals with HTN following a 16-week (POST) supervised aerobic exercise training (SupExT) intervention with an attentional control (AC) group, and (2) to determine whether the changes observed were maintained following six months (6 M) of unsupervised time. Participants (n = 219) were randomly assigned into AC or SupExT groups. All participants underwent a hypocaloric diet. At POST, all participants received diet and physical activity advice for the following 6 M, with no supervision. All measurements were assessed pre-intervention (PRE), POST, and after 6 M. From PRE to POST, MUO participants became MHO with improved (p < 0.05) total cholesterol (TC, ∆ = −12.1 mg/dL), alanine aminotransferase (∆ = −8.3 U/L), glucose (∆ = −5.5 mg/dL), C-reactive protein (∆ = −1.4 mg/dL), systolic blood pressure (SBP), and cardiorespiratory fitness (CRF) compared to unhealthy optimal cut-off values. However, after 6 M, TC, glucose, and SBP returned to unhealthy values (p < 0.05). In a non-physically active population with obesity and HTN, a 16-week SupExT and diet intervention significantly improves cardiometabolic profile from MUO to MHO. However, after 6 M of no supervision, participants returned to MUO. The findings of this study highlight the need for regular, systematic, and supervised diet and exercise programs to avoid subsequent declines in cardiometabolic health.P.C., A.M.A.-B., and I.G.-A. were supported by the Basque Government with predoctoral grants. This study was supported by the University of the Basque Country (EHU14/08, PPGA18/15)
An explicit height bound for the classical modular polynomial
For a prime m, let Phi_m be the classical modular polynomial, and let
h(Phi_m) denote its logarithmic height. By specializing a theorem of Cohen, we
prove that h(Phi_m) <= 6 m log m + 16 m + 14 sqrt m log m. As a corollary, we
find that h(Phi_m) <= 6 m log m + 18 m also holds. A table of h(Phi_m) values
is provided for m <= 3607.Comment: Minor correction to the constants in Theorem 1 and Corollary 9. To
appear in the Ramanujan Journal. 17 pages
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