424 research outputs found
Anatypical active cell death process underlies the fungicidal activity of ciclopiroxolamine against the yeast Saccharomyces cerevisiae
Ciclopirox olamine (CPO), a fungicidal agent widely used in clinical practice,
induced in Saccharomyces cerevisiae an active cell death (ACD) process characterized
by changes in nuclear morphology and chromatin condensation associated
with the appearance of a population in the sub-G0/G1 cell cycle phase and an arrest
in the G2/M phases. This ACD was associated neither with intracellular reactive
oxygen species (ROS) signaling, as revealed by the use of different classes of ROS
scavengers, nor with a terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)-positive phenotype. Furthermore, CPO-induced cell death
seems to be dependent on unknown protease activity but independent of the apoptotic regulators Aif1p and Yca1p and of autophagic pathways involving
Apg5p, Apg8p and Uth1p. Our results show that CPO triggers in S. cerevisiae an
atypical nonapoptotic, nonautophagic ACD with as yet unknown regulators
Channel flow, tectonic overpressure, and exhumation of high-pressure rocks in the greater himalayas
The Himalayas are the archetype of continental collision, where a number of long-standing fundamental problems persist in the Greater Himalayan Sequence (GHS): (1) contemporaneous reverse and normal faulting, (2) inversion of metamorphic grade, (3) origin of high-(HP) and ultrahigh-pressure (UHP) rocks, (4) mode of ductile extrusion and exhumation of HP and UHP rocks close to the GHS hanging wall, (5) flow kinematics in the subduction channel, and (6) tectonic overpressure, here defined as TOP  Combining double low line Pĝ•PL where P is total (dynamic) pressure and PL is lithostatic pressure. In this study we couple Himalayan geodynamics to numerical simulations to show how one single model, upward-Tapering channel (UTC) flow, can be used to find a unified explanation for the evidence. The UTC simulates a flat-ramp geometry of the main underthrust faults, as proposed for many sections across the Himalayan continental subduction. Based on the current knowledge of the Himalayan subduction channel geometry and geological/geophysical data, the simulations predict that a UTC can be responsible for high TOP ( > 2). TOP increases exponentially with a decrease in UTC mouth width, and with an increase in underthrusting velocity and channel viscosity. The highest overpressure occurs at depths < ĝ'60 km, which, combined with the flow configuration in the UTC, forces HP and UHP rocks to exhume along the channel's hanging wall, as in the Himalayas. By matching the computed velocities and pressures wi
Antibacterial activity of a new monocarbonyl analog of curcumin MAC 4 is associated with divisome disruption
Curcumin (CUR) is a symmetrical dicarbonyl compound with antibacterial activity. On the other hand, pharmacokinetic and chemical stability limitations hinder its therapeutic application. Monocarbonyl analogs of curcumin (MACs) have been shown to overcome these barriers. We synthesized and investigated the antibacterial activity of a series of unsymmetrical MACs derived from acetone against Mycobacterium tuberculosis and Gram-negative and Gram-positive species. Phenolic MACs 4, 6 and 8 showed a broad spectrum and potent activity, mainly against M. tuberculosis, Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus (MRSA), with MIC (minimum inhibitory concentration) values ranging from 0.9 to 15.6 µg/mL. The investigation regarding toxicity on human lung cells (MRC-5 and A549 lines) revealed MAC 4 was more selective than MACs 6 and 8, with SI (selectivity index) values ranging from 5.4 to 15.6. In addition, MAC 4 did not demonstrate genotoxic effects on A549 cells and it was more stable than CUR in phosphate buffer (pH 7.4) for 24 h at 37 °C. Fluorescence and phase contrast microscopies indicated that MAC 4 has the ability to disrupt the divisome of Bacillus subtilis without damaging its cytoplasmic membrane. However, biochemical investigations demonstrated that MAC 4 did not affect the GTPase activity of B. subtilis FtsZ, which is the main constituent of the bacterial divisome. These results corroborated that MAC 4 is a promising antitubercular and antibacterial agent
Spectroscopic variability of two Oe stars
The Oe stars HD45314 and HD60848 have recently been found to exhibit very
different X-ray properties: whilst HD60848 has an X-ray spectrum and emission
level typical of most OB stars, HD45314 features a much harder and brighter
X-ray emission, making it a so-called gamma Cas analogue. Monitoring the
optical spectra could provide hints towards the origin of these very different
behaviours. We analyse a large set of spectroscopic observations of HD45314 and
HD60848, extending over 20 years. We further attempt to fit the H-alpha line
profiles of both stars with a simple model of emission line formation in a
Keplerian disk. Strong variations in the strengths of the H-alpha, H-beta, and
He I 5876 emission lines are observed for both stars. In the case of HD60848,
we find a time lag between the variations in the equivalent widths of these
lines. The emission lines are double peaked with nearly identical strengths of
the violet and red peaks. The H-alpha profile of this star can be successfully
reproduced by our model of a disk seen under an inclination of 30 degrees. In
the case of HD45314, the emission lines are highly asymmetric and display
strong line profile variations. We find a major change in behaviour between the
2002 outburst and the one observed in 2013. This concerns both the relationship
between the equivalent widths of the various lines and their morphologies at
maximum strength (double-peaked in 2002 versus single-peaked in 2013). Our
simple disk model fails to reproduce the observed H-alpha line profiles of
HD45314. Our results further support the interpretation that Oe stars do have
decretion disks similar to those of Be stars. Whilst the emission lines of
HD60848 are explained by a disk with a Keplerian velocity field, the disk of
HD45314 seems to have a significantly more complex velocity field that could be
related to the phenomenon that produces its peculiar X-ray emission.Comment: Accepted for Publication in A&
Shade and Altitude Implications on the Physical and Chemical Attributes of Green Coffee Beans from Gorongosa Mountain, Mozambique
Coffea arabica L. is as a tropical crop that can be grown under monocrop or agroforestry
(AFS) systems, usually at altitudes greater than 600 m, with suitable environmental conditions
to bean quality. This study aimed to assess the effect of altitude (650, 825, and 935 m) and light
conditions (deep shade—DS, and moderate shade—MS provided by native trees, and full Sun—FS)
on the physical and chemical attributes of green coffee beans produced in the Gorongosa Mountain.
Regardless of altitude, light conditions (mainly MS and FS) scarcely affected most of the studied
physical and chemical attributes. Among the few exceptions in physical attributes, bean mass tended
to lower values under FS in all three altitudes, whereas bean density increased under FS at 650 m.
As regards the chemical compound contents, sporadic changes were found. The rises in trigonelline
(MS and FS at 935 m), soluble sugars (FS at 935 m), and the decline in p-coumaric acid (MS and FS at
825 m), may indicate an improved sensory profile, but the rise in FQAs (FS at 825 m) could have a
negative impact. These results highlight a relevant uncertainty of the quality changes of the obtained
bean. Altitude (from 650 to 935 m) extended the fruit maturation period by four weeks, and altered
a larger number of bean attributes. Among physical traits, the average sieve (consistent tendency),
bean commercial homogeneity, mass, and density increased at 935 m, whereas the bean became less
yellowish and brighter at 825 and 935 m (b*, C* colour attributes), pointing to good bean trade quality,
usually as compared with beans from 650 m. Furthermore, at 935 m trigonelline and 5-CQA (MS
and FS) increased, whereas FQAs and diCQAs isomers declined (in all light conditions). Altogether,
these changes likely contributed to improve the sensory cup quality. Caffeine and p-coumaric acid
showed mostly inconsistent variations. Overall, light conditions (FS, MS, or DS) did not greatly and consistently altered bean physical and chemical attributes, whereas altitude (likely associated with
lower temperature, greater water availability (rainfall/fog), and extended maturation period) was a
major driver for bean changes and improved qualityinfo:eu-repo/semantics/publishedVersio
nutrition and performance in football
Nutrition is an undeniable part of promoting health and performance among football (soccer) players.
Nevertheless, nutritional strategies adopted in elite football can vary significantly depending on culture,
habit and practical constraints and might not always be supported by scientific evidence. Therefore, a group of
28 Portuguese experts on sports nutrition, sports science and sports medicine sought to discuss current practices in the elite football landscape and review the existing evidence on nutritional strategies to be applied when supporting football players. Starting from understanding football?s physical and physiological demands, five different moments were identified: preparing to play, match-day, recovery after matches, between matches and during injury or rehabilitation periods. When applicable, specificities of nutritional support to young athletes and female players were also addressed. The result is a set of practical recommendations that gathered consensus among involved experts, highlighting carbohydrates periodisation, hydration and conscious use of dietary supplements.D915-7373-ED16 | Cesar LeaoN/
Variability monitoring of OB stars during the Mons campaign
We present preliminary results of a 3-month campaign carried out in the
framework of the Mons project, where time-resolved Halpha observations are used
to study the wind and circumstellar properties of a number of OB stars.Comment: 2 pages, 1 figure. To appear in proceedings of IAUS272 'Active OB
Stars: Structure, Evolution, Mass Loss and Critical Limits
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