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Measurements of K∗(892)0 and φ(1020) resonance production in Pb–Pb and pp collisions at √sNN = 5.02 TeV with the ALICE detector at the Large Hadron Collider are reported. The resonances are measured at midrapidity (|y| < 0.5) via their hadronic decay channels and the transverse momentum (pT) distributions are obtained for various collision centrality classes up to pT = 20 GeV/c. The pT-integrated yield ratio K∗(892)0/K in Pb–Pb collisions shows significant suppression relative to pp collisions and decreases towards more central collisions. In contrast, the φ(1020)/K ratio does not show any suppression. Furthermore, the measured K∗(892)0/K ratio in central Pb–Pb collisions is significantly suppressed with respect to the expectations based on a thermal model calculation, while the φ(1020)/K ratio agrees with the model prediction. These measurements are an experimental demonstration of rescattering of K∗(892)0 decay products in the hadronic phase of the collisions. The K∗(892)0/K yield ratios in Pb–Pb and pp collisions are used to estimate the time duration between chemical and kinetic freeze-out, which is found to be ∼ 4–7 fm/c for central collisions. The pT-differential ratios of K∗(892)0/K, φ(1020)/K, K∗(892)0/π , φ(1020)/π , p/K∗(892)0 and p/φ(1020) are also presented for Pb–Pb and pp collisions at √sNN = 5.02 TeV. These ratios show that the rescattering effect is predominantly a low-pT phenomenon.
The first evidence of spin alignment of vector mesons (K*0 and ϕ) in heavy-ion collisions at the Large Hadron Collider (LHC) is reported. The spin density matrix element ρ00 is measured at midrapidity (|y|< 0.5) in Pb-Pb collisions at a center-of-mass energy (√sNN) of 2.76 TeV
with the ALICE detector. ρ00 values are found to be less than 1/3 (1/3 implies no spin alignment) at low transverse momentum (pT<2 GeV/c) for K*0 and ϕ at a level of 3σ and 2σ, respectively. No significant spin alignment is observed for the K0S meson (spin = 0) in Pb-Pb collisions and for the vector mesons in pp collisions. The measured spin alignment is unexpectedly large but qualitatively consistent with the expectation from models which attribute it to a polarization of quarks in the presence of angular momentum in heavy-ion collisions and a subsequent hadronization by the process of recombination.
The transverse momentum (pT) differential yields of (anti-)3He and (anti-)3H measured in p-Pb collisions at sNN−−−√ = 5.02 TeV with ALICE at the Large Hadron Collider (LHC) are presented. The ratios of the pT-integrated yields of (anti-)3He and (anti-)3H to the proton yields are reported, as well as the pT dependence of the coalescence parameters B3 for (anti-)3He and (anti-)3H. For (anti-)3He, the results obtained in four classes of the mean charged-particle multiplicity density are also discussed. These results are compared to predictions from a canonical statistical hadronization model and coalescence approaches. An upper limit on the total yield of 4He¯ is determined.
On 6 October 2012, the remains of a frigatebird were recovered at João Barrosa beach (16°01.387’N, 022°43.610’W), southeastern Boavista, Cape Verde Islands. The carcass had been found in mid September 2012, during a beach survey to monitor loggerhead turtle nesting activity in the area and was then buried in the sand. The field assistant of the Cabo Verde Natura 2000 turtle project who found the bird indicated the location of the corpse to the first author. His description of the bird allowed it to be identified as an adult female magnificent frigatebird Fregata magnificens Mathews, 1914. The remains consisted of numerous black and white feathers as well as several bones, including the skull, thorax and wing bones, which are preserved at the Cabo Verde Natura 2000 headquarters at Sal Rei, Boavista. Some feathers, together with remains of an egg and tissue of a mummified male found at Ilhéu de Baluarte in 2005 (see below), were deposited at the Centro de Análise Molecular, Centro de Investigação em Biodiversidade e Recursos Genéticos (CMA/CIBIO), Vairão, Portugal.
On 10 February 2012, at 0845 UTC, a mass stranding involving seven (six adults and a juvenile) pygmy killer whales Feresa attenuata Gray, 1874 occurred at Praia de Boa Esperança (16º12’26”N, 22º52’00”W), along the northern coast of Boavista island, Cape Verde Islands. The event was witnessed by a group of kite-surfers, who managed to move three animals (two adults and a juvenile) back to the sea. No re-strandings were noted. At 1330 UTC, staff of the Protected Areas Department visited the site and recorded four specimens (two alive and two dead). At 1700 UTC, only two carcasses were found on the beach, the others apparently having been washed out to sea.
On 12 July 2013, an adult female loggerhead sea turtle Caretta caretta with an almost complete longitudinal carapace fracture was observed nesting and returning to sea at João Barrosa beach, Boa Vista, Cape Verde Islands. Due to the evident fracture instability and the likelihood of subsequent system infection development, an intervention was planned to prevent further health decline and eventual death. Beach surveillance was increased to raise recapture possibilities, based on the most likely nesting days for this individual. After 53 days, the animal hauled out again and was allowed to lay eggs before taken away for wound cleaning, stabilization, medication administration and surgery. An orthopaedic surgical intervention for shell repair was performed under field injectable general anaesthesia. The fracture was stabilised in six places by means of four marine resistant stainless steel plates and two orthopaedic wires screwed to the carapace. Finally, all implanted material was covered and protected with epoxy resin to maintain a smooth carapace surface and prevent potential entanglement.
Based on both stranding and sighting records, recent data on the status and distribution of whales and dolphins in the Cape Verde Islands are presented, including records of four taxa new to the archipelago, viz. Common minke whale Balaenoptera acutorostrata, Dwarf sperm whale Kogia sima, beaked whale Mesoplodon cf. europaeus and False killer whale Pseudorca crassidens. Distribution elsewhere in the tropical eastern Atlantic and some taxonomic issues are discussed.
In the North Atlantic, the waters surrounding the Cape Verde Islands are a "potential hot spot" for cookiecutter shark Isistius spp. interactions with cetaceans. These occurrences were recently identified by the improved efforts of researchers to document cetacean strandings in the Cape Verde archipelago, as well as by the photo identification efforts of live whales and dolphins. The documentation of individual and mass stranding events confirmed that cookiecutter shark interactions with cetaceans in Cape Verde seas are remarkably common.
Humpback whales Megaptera novaeangliae perform the longest known migrations among mammalian species (Stone et al. 1990, Rasmussen et al. 2007), feeding at high latitudes during the summer and undertaking annual journeys to their wintering breeding grounds in warm and shallow tropical waters (Winn & Reichley 1985, Clapham & Mead 1999). Due to breeding site fidelity and temporal separation at low latitudes, gene flow between Northern and Southern Hemisphere populations appears to be very limited (Rizzo & Schulte 2009). However, inter-oceanic exchange has recently been documented (Pomilla & Rosenbaum 2005, Stevick et al. 2010), demonstrating that philopatry may not be as strong as previously inferred (cf. Baker et al. 1993, 1994, Valsecchi et al. 1997).
The abundance of humpback whales occurring around Boa Vista, Cape Verde Islands, was estimated by markrecapture modelling. Photographs of markings on tail flukes of individual whales were collected during the breeding season. Sighting histories were constructed for each individual and an abundance of 171 animals was estimated using a Jolly-Seber mark-recapture model. Correcting for known biases arising due to sex-specific behaviour and temporary emigration insofar as possible, an estimate of 260 whales was obtained. This is significantly higher than the previous estimate of 99 humpback whales from this region. Due to limited survey effort it is not known how representative the study area is of the entire Cape Verde archipelago and this estimate may be considered to be biased low and serves as a minimum estimate. The high recapture probability (0.37) coupled with the low abundance is consistent with a small local population. The low survival rate (0.86) suggests possible emigration and further studies are needed to assess connectivity between humpback whales breeding in Cape Verde and other breeding locations. The amount of exchange between groups of whales breeding in Cape Verde and adjacent areas remains unknown. It is unclear whether the abundance estimate herein applies to part of an isolated population or part of a larger and continuous one.
During August-September 2014 and 2015, yachtbased surveys were conducted in the Cape Verde archipelago with the main objective of trying to locate humpback whales Megaptera novaeangliae during the late boreal summer (Berrow et al. 2014). Spring breeding humpbacks in Cape Verde waters are known to have their feeding grounds in the high Arctic (e.g. Wenzel et al. 2009). While these animals have generally left the breeding grounds by mid-May, a number of sightings during the summer months (June- August) have raised the possibility that animals from southern stocks may occasionally reach as far north as Cape Verde (Hazevoet et al. 2011).
Gervais’ beaked whale Mesoplodon europaeus (Gervais, 1855) is restricted to the Atlantic Ocean. Although most records are from the North Atlantic, it is probably continuously distributed in deep warm waters around the equator (Mead 1989, Norman & Mead 2001). Its occurrence in West Africa is poorly known, as records are rare. It is classified as Data Deficient (Taylor et al. 2008).
Autophagy is a core molecular pathway for the preservation of cellular and organismal homeostasis. Pharmacological and genetic interventions impairing autophagy responses promote or aggravate disease in a plethora of experimental models. Consistently, mutations in autophagy-related processes cause severe human pathologies. Here, we review and discuss preclinical data linking autophagy dysfunction to the pathogenesis of major human disorders including cancer as well as cardiovascular, neurodegenerative, metabolic, pulmonary, renal, infectious, musculoskeletal, and ocular disorders.
Systematic, faunistic and ecological aspects of the six families and 34 species and subspecies in the order Ephemeroptera currently recorded from Cuba are reviewed based primarily on a reference collection located at the Universidad de Oriente (Santiago de Cuba), collections at the Institute of Ecology and Systematics (Havana) and historic literature. A key to nymphs is included with photographs of significant features of many species. An annotated list of species is presented with comments on type localities, species ecology and distribution. The morpho- ecological types of the nymphs are updated according to current taxonomic changes, and indicator species of organic contamination are analyzed according to the BMWP-Cub index. Based on present data, mayflies are best collected between January and June although many species are present throughout the year, and almost half of the species are widely distributed. Possible routes of penetration from the continents toward Cuba are from South America through the arc of islands formed by the Lesser Antilles, from Central and South America through the peninsula of Yucatan, and via an ancient landspan or island chain from northern South America (GAARlandia). With one exception, there is no evidence for dispersal of species from North America (through Florida) to Cuba (and then to the Antilles) or vice versa. The pattern of geographical distribution of Ephemeroptera inside Cuba is very similar to that of the orders Trichoptera and Odonata. The greatest number of species is found in the Eastern region and the fewest in the Central and Central-East regions. The high endemism (76.5%) is probably due to geographical isolation and processes that bring about this phenomenon together with the low vagility that characterizes the order.
Epoxyeicosatrienoic acids (EETs) are signaling lipids produced by the cytochrome P450-(CYP450)-mediated epoxygenation of arachidonic acid. EETs have numerous biological effects on the vascular system, but aspects including their species specificity make their effects on vascular tone controversial. CYP450 enzymes require the 450-reductase (POR) for their activity. We set out to determine the contribution of endothelial CYP450 to murine vascular function using isolated aortic ring preparations from tamoxifen-inducible endothelial cell-specific POR knockout mice (ecPOR−/−). Constrictor responses to phenylephrine were similar between control (CTR) and ecPOR−/− mice. Contrastingly, sensitivity to the thromboxane receptor agonist U46619 and prostaglandin E2 (PGE2) was increased following the deletion of POR. Ex vivo incubation with a non-hydrolyzable EET (14,15-EE-8(Z)-E, EEZE) reversed the increased sensitivity to U46619 to the levels of CTR. EETs had no effect on vascular tone in phenylephrine-preconstricted vessels, but dilated vessels contracted with U46619 or PGE2. As U46619 acts through RhoA-dependent kinase, this system was analyzed. The deletion of POR affected the expression of genes in this pathway and the inhibition of Rho-GTPase with SAR407899 decreased sensitivity to U46619. These data suggest that EET and prostanoid crosstalk at the receptor level and that lack of EET production sensitizes vessels to vasoconstriction via the induction of the Rho kinase system.
Vascular biotransformation of organic nitrates is independent of cytochrome P450 monooxygenases
(2021)
Background and Purpose: Organic nitrates such as nitroglycerin (NTG) or pentaerythritol tetranitrate (PETN) have been used for over a century in the treatment of angina or ischaemic heart disease. These compounds are prodrugs which release their nitrovasodilators upon enzymic bioactivation by aldehyde dehydrogenase (ALDH2) or cytochromes P450 (CYP). Whereas ALDH2 is known to directly activate organic nitrates in vessels, the contribution of vascular CYPs is unknown and was studied here.
Experimental Approach: As all CYPs depend on cytochrome P450 reductase (POR) as electron donor, we generated a smooth muscle cell-specific, inducible knockout mouse of POR (smcPOR−/−) to investigate the contribution of POR/CYP to vascular biotransformation of organic nitrates.
Key Results: Microsomes containing recombinant CYPs expressed in human vascular tissues released nitrite from NTG and PETN with CYP2C9 and CYP2C8 being most efficient. SFK525, a CYP suicide inhibitor, blocked this effect. smcPOR−/− mice exhibited no obvious cardiovascular phenotype (normal cardiac weight and endothelium-dependent relaxation) and plasma and vascular nitrite production was similar to control (CTL) animals. NTG- and PETN-induced relaxation of isolated endothelium-intact or endothelium-denuded vessels were identical between CTL and smcPOR−/−. Likewise, nitrite release from organic nitrates in aortic rings was not affected by deletion of POR in smooth muscle cells (SMCs). In contrast, inhibition of ALDH2 by benomyl (10 μM) inhibited NTG-induced nitrite production and relaxation. Deletion of POR did not modulate this response.
Conclusions and Implications: Our data suggest that metabolism by vascular CYPs does not contribute to the pharmacological function of organic nitrates.