Vacuolar proton-translocating ATPases (V-ATPases) play a central role in organelle acidification in all eukaryotic cells. To address the role of the yeast V-ATPase in vacuolar and cytosolic pH ...homeostasis, ratiometric pH-sensitive fluorophores specific for the vacuole or cytosol were introduced into wild-type cells and vma mutants, which lack V-ATPase subunits. Transiently glucose-deprived wild-type cells respond to glucose addition with vacuolar acidification and cytosolic alkalinization, and subsequent addition of K+ ion increases the pH of both the vacuole and cytosol. In contrast, glucose addition results in an increase in vacuolar pH in both vma mutants and wild-type cells treated with the V-ATPase inhibitor concanamycin A. Cytosolic pH homeostasis is also significantly perturbed in the vma mutants. Even at extracellular pH 5, conditions optimal for their growth, cytosolic pH was much lower, and response to glucose was smaller in the mutants. In plasma membrane fractions from the vma mutants, activity of the plasma membrane proton pump, Pma1p, was 65–75% lower than in fractions from wild-type cells. Immunofluorescence microscopy confirmed decreased levels of plasma membrane Pma1p and increased Pma1p at the vacuole and other compartments in the mutants. Pma1p was not mislocalized in concanamycin-treated cells, but a significant reduction in cytosolic pH under all conditions was still observed. We propose that short-term, V-ATPase activity is essential for both vacuolar acidification in response to glucose metabolism and for efficient cytosolic pH homeostasis, and long-term, V-ATPases are important for stable localization of Pma1p at the plasma membrane.
The ergogenic effect of caffeine is well-established, but the extent of its consumption in sport is unknown at the present. The use of caffeine was considered "prohibited" until 2004, but this ...stimulant was moved from the List of Prohibited Substances to the Monitoring Program of the World Anti-Doping Agency to control its use by monitoring urinary caffeine concentration after competition. However, there is no updated information about the change in the use of caffeine as the result of its inclusion in the Monitoring Program. The aim of this study was to describe the changes in urine caffeine concentration from 2004 to 2015. A total of 7488 urine samples obtained in official competitions held in Spain and corresponding to athletes competing in Olympic sports (2788 in 2004, 2543 in 2008, and 2157 in 2015) were analyzed for urine caffeine concentration. The percentage of samples with detectable caffeine (i.e., >0.1 μg/mL) increased from ~70.1%, in 2004⁻2008 to 75.7% in 2015. The median urine caffeine concentration in 2015 (0.85 μg/mL) was higher when compared to the median value obtained in 2004 (0.70 μg/mL;
< 0.05) and in 2008 (0.70 μg/mL;
< 0.05). The urine caffeine concentration significantly increased from 2004 to 2015 in aquatics, athletics, boxing, judo, football, weightlifting, and rowing (
< 0.05). However, the sports with the highest urine caffeine concentration in 2015 were cycling, athletics, and rowing. In summary, the concentration of caffeine in the urine samples obtained after competition in Olympic sports in Spain increased from 2004 to 2015, particularly in some disciplines. These data indicate that the use of caffeine has slightly increased since its removal from the list of banned substances, but urine caffeine concentrations suggest that the use of caffeine is moderate in most sport specialties. Athletes of individual sports or athletes of sports with an aerobic-like nature are more prone to using caffeine in competition.
To investigate the effects of a caffeine-containing energy drink on soccer performance during a simulated game. A second purpose was to assess the post-exercise urine caffeine concentration derived ...from the energy drink intake.
Nineteen semiprofessional soccer players ingested 630 ± 52 mL of a commercially available energy drink (sugar-free Red Bull®) to provide 3 mg of caffeine per kg of body mass, or a decaffeinated control drink (0 mg/kg). After sixty minutes they performed a 15-s maximal jump test, a repeated sprint test (7 × 30 m; 30 s of active recovery) and played a simulated soccer game. Individual running distance and speed during the game were measured using global positioning satellite (GPS) devices. In comparison to the control drink, the ingestion of the energy drink increased mean jump height in the jump test (34.7 ± 4.7 v 35.8 ± 5.5 cm; P<0.05), mean running speed during the sprint test (25.6 ± 2.1 v 26.3 ± 1.8 km · h(-1); P<0.05) and total distance covered at a speed higher than 13 km · h(-1) during the game (1205 ± 289 v 1436 ± 326 m; P<0.05). In addition, the energy drink increased the number of sprints during the whole game (30 ± 10 v 24 ± 8; P<0.05). Post-exercise urine caffeine concentration was higher after the energy drink than after the control drink (4.1 ± 1.0 v 0.1 ± 0.1 µg · mL(-1); P<0.05).
A caffeine-containing energy drink in a dose equivalent to 3 mg/kg increased the ability to repeatedly sprint and the distance covered at high intensity during a simulated soccer game. In addition, the caffeinated energy drink increased jump height which may represent a meaningful improvement for headers or when players are competing for a ball.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This paper presents the evaluation and quantification of energy poverty in Madrid, at the city and district level. The incidence of energy poverty is assessed by means of the High Share of Energy ...Expenditure in Income indicator combined with the monetary poverty perspective, enabling to identify different energy-poor household profiles. The study links the city and district statistical levels. The analysis of the different household groups at the city level allows identifying several determining factors linked to energy poverty in Madrid. Based on these determining factors, this research explores district statistics by following an area-based approach and assesses its energy poverty distribution. The High Energy Requirements index is then built on these determining factors to help to pinpoint the urban areas where energy-poor households are more prone to be located. The results show that 22.7% of households are at risk of energy poverty and suggest a need for effectively incorporating households’ income levels and a monetary approach into energy poverty assessments. Finally, based on the two-scale (city and district) analysis conducted, this paper concludes with energy retrofitting policy guidelines, distinguishing between the different levels of funding, and the efficiency measures to be implemented according to each particular energy poverty condition.
•A total of 22.7% of Madrid's households is at risk of energy poverty.•An overlap between energy and monetary poverty takes place in 7% of households.•The Variables used for the EP district-level assessment are determined based on the analysis of city statistics.•The High Energy Requirements index enables the identification of energy-poor households concentrated areas.
•Determination of 28 doping-related substances via LC–MS-QTOF analysis is presented.•Fast, high-throughput and cost-effective SPE on microplates is used for screening.•Full scan acquisition mode is ...proposed for initial testing.•Product ion MS/MS selected transitions are used for confirmation.•Validation results for all tested substances fulfil WADA requirements.
A complete analytical protocol for the determination of 25 doping-related peptidic drugs and 3 metabolites in urine was developed by means of accurate-mass quadrupole time-of-flight (Q-TOF) LC–MS analysis following solid-phase extraction (SPE) on microplates and conventional SPE pre-treatment for initial testing and confirmation, respectively. These substances included growth hormone releasing factors, gonadotropin releasing factors and anti-diuretic hormones, with molecular weights ranging from 540 to 1320Da. Optimal experimental conditions were stablished after investigation of different parameters concerning sample preparation and instrumental analysis. Weak cation exchange SPE followed by C18 HPLC chromatography and accurate mass detection provided the required sensitivity and selectivity for all the target peptides under study. 2mg SPE on 96-well microplates can be used in combination with full scan MS detection for the initial testing, thus providing a fast, cost-effective and high-throughput protocol for the processing of a large batch of samples simultaneously. On the other hand, extraction on 30mg SPE cartridges and subsequent target MS/MS determination was the protocol of choice for confirmatory purposes. The methodology was validated in terms of selectivity, recovery, matrix effect, precision, sensitivity (limit of detection, LOD), cross contamination, carryover, robustness and stability. Recoveries ranged from 6 to 70% (microplates) and 17–95% (cartridges), with LODs from 0.1 to 1ng/mL. The suitability of the method was assessed by analyzing different spiked or excreted urines containing some of the target substances.
PURPOSEThe purpose of this study was to determine the oral dose of caffeine needed to increase muscle force and power output during all-out single multijoint movements.
METHODSThirteen ...resistance-trained men underwent a battery of muscle strength and power tests in a randomized, double-blind, crossover design, under four different conditions(a) placebo ingestion (PLAC) or with caffeine ingestion at doses of (b) 3 mg·kg body weight (CAFF3mg), (c) 6 mg·kg (CAFF6mg), and (d) 9 mg·kg (CAFF9mg). The muscle strength and power tests consisted in the measurement of bar displacement velocity and muscle power output during free-weight full-squat (SQ) and bench press (BP) exercises against four incremental loads (25%, 50%, 75%, and 90% one-repetition maximum 1RM). Cycling peak power output was measured using a 4-s inertial load test. Caffeine side effects were evaluated at the end of each trial and 24 h later.
RESULTSMean propulsive velocity at light loads (25%–50% 1RM) increased significantly above PLAC for all caffeine doses (5.4%–8.5%, P = 0.039–0.003). At the medium load (75% 1RM), CAFF3mg did not improve SQ or BP muscle power or BP velocity. CAFF9mg was needed to enhance BP velocity and SQ power at the heaviest load (90% 1RM) and cycling peak power output (6.8%–11.7%, P = 0.03–0.05). The CAFF9mg trial drastically increased the frequency of the adverse side effects (15%–62%).
CONCLUSIONSThe ergogenic dose of caffeine required to enhance neuromuscular performance during a single all-out contraction depends on the magnitude of load used. A dose of 3 mg·kg is enough to improve high-velocity muscle actions against low loads, whereas a higher caffeine dose (9 mg·kg) is necessary against high loads, despite the appearance of adverse side effects.
Summary
The filamentous fungus Ashbya gossypii is currently used for the industrial production of vitamin B2. Furthermore, the ability of A. gossypii to grow using low‐cost substrates together with ...the inexpensive downstream processing makes this fungus an attractive biotechnological chassis. Indeed, the production in A. gossypii of other high‐added value compounds such as folic acid, nucleosides and biolipids has been described. Hence, the development of new methods to expand the molecular toolkit for A. gossypii genomic manipulation constitutes an important issue for the biotechnology of this fungus. In this work, we present a one‐vector CRISPR/Cas9 system for genomic engineering of A. gossypii. We demonstrate the efficiency of the system as a marker‐less approach for nucleotide deletions and substitutions both with visible and invisible phenotypes. Particularly, the system has been validated for three types of genomic editions: gene inactivation, the genomic erasure of loxP scars and the introduction of point mutations. We anticipate that the use of the CRISPR/Cas9 system for A. gossypii will largely contribute to facilitate the genomic manipulations of this industrial fungus in a marker‐less manner.
Ashbya gossypii is a model filamentous fungus and industrially relevant cell factory currently used for the industrial production of vitamin B2. The application of the CRISPR‐Cas9 system provides an efficient and precise method for genome engineering of eukaryotic genomes. To facilitate the genetic manipulation of A. gossypii, we developed a highly efficient CRISPR‐Cas9 system for marker‐free introduction of precise insertions, deletions and point mutations. This system is based on the use of a single vector for the expression of CAS9 and sgRNA to avoid the difficulties inherent to the genome edition of syncytial cells.
Danzirly is a striking bilingual poetry collection that fiercely examines the nuances of the American Dream for Latinx people in the United States. With a backdrop of stringent immigration policies, ...the #MeToo movement, and the increasingly tangible threat of climate change, this collection considers multigenerational Latinx identities in a rapidly changing country and world. Through the author's Colombian American lens, the poems explore the intersections of culture, gender, history, and intergenerational grief. Danzirly does not shy away from confronting traditional gender roles, religion, and anxieties surrounding climate change and the digital age. Gloria Muñoz addresses Latinx stereotypes and powerfully dismantles them in poetic form, juxtaposing the promised wonders of a life in America with the harsh realities that immigrants face as they build their lives and raise their families here. Winner of the Academy of American Poets' Ambroggio Prize, this collection of poems is an unforgettable reckoning of the grief and beauty that pulses through twenty-first-century America.
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