1,548 research outputs found
Identification of a very long chain polyunsaturated fatty acid Δ4-desaturase from the microalga Pavlova lutheri11The sequence reported in this paper has been submitted to GenBank database under the accession number AY332747.
AbstractPavlova lutheri, a marine microalga, is rich in the very long chain polyunsaturated fatty acids (VLCPUFAs) eicosapentaenoic (20:5n-3) and docosahexaenoic (22:6n-3) acids. Using an expressed sequence tag approach, we isolated a cDNA designated Pldes1, and encoding an amino acid sequence showing high similarity with polyunsaturated fatty acid front-end desaturases. Heterologous expression in yeast demonstrated that PlDES1 desaturated 22:5n-3 and 22:4n-6 into 22:6n-3 and 22:5n-6 respectively, and was equally active on both substrates. Thus, PlDES1 is a novel VLCPUFA Δ4-desaturase. Pldes1 expression is four-fold higher during the mid-exponential phase of growth compared to late exponential and stationary phases
Helioseismology and solar neutrinos: an update
We review recent advances concerning helioseismology, solar models and solar
neutrinos. Particularly we address the following points: i) helioseismic tests
of recent SSMs; ii) predictions of the Beryllium neutrino flux based on
helioseismology; iii) helioseismic tests regarding the screening of nuclear
reactions in the Sun.Comment: 7 pages with 6 eps figure included, LaTeX file with espcrc2.sty, to
appear on the Proceedings of "EuroConference on Frontiers in Particle
Astrophysics and Cosmology", San Feliu de Guixols, Spain, 30 September -5
October 200
Triiodothyronine suppresses humoral immunity but not T-cell-mediated immune response in incubating female eiders (Somateria mollissima)
Immunity is believed to share limited resources with other physiological
functions and this may partly account for the fitness costs of reproduction.
Previous studies have shown that the acquired immunity of female common eiders
(Somateria mollissima) is suppressed during the incubation fast. To save
energy, triiodothyronine (T3) is adaptively decreased during fasting in most
bird species, despite T3 levels are maintained throughout incubation in female
eiders. However, the relationship between thyroid hormones and the immune
system is not fully understood. The current study aimed to determine the
endocrine mechanisms that underlie immunosuppression in incubating female
eiders. ..
The Sea Peoples, from Cuneiform Tablets to Carbon Dating
The 13th century BC witnessed the zenith of the Aegean and Eastern Mediterranean civilizations which declined at the end of the Bronze Age, ∼3200 years ago. Weakening of this ancient flourishing Mediterranean world shifted the political and economic centres of gravity away from the Levant towards Classical Greece and Rome, and led, in the long term, to the emergence of the modern western civilizations. Textual evidence from cuneiform tablets and Egyptian reliefs from the New Kingdom relate that seafaring tribes, the Sea Peoples, were the final catalyst that put the fall of cities and states in motion. However, the lack of a stratified radiocarbon-based archaeology for the Sea People event has led to a floating historical chronology derived from a variety of sources spanning dispersed areas. Here, we report a stratified radiocarbon-based archaeology with anchor points in ancient epigraphic-literary sources, Hittite-Levantine-Egyptian kings and astronomical observations to precisely date the Sea People event. By confronting historical and science-based archaeology, we establish an absolute age range of 1192–1190 BC for terminal destructions and cultural collapse in the northern Levant. This radiocarbon-based archaeology has far-reaching implications for the wider Mediterranean, where an elaborate network of international relations and commercial activities are intertwined with the history of civilizations
Identification of Novel F2-Isoprostane Metabolites by Specific UDP-Glucuronosyltransferases
UDP-glucuronosyltransferases (UGTs) catalyze the conjugation of glucuronic acid with endogenous and exogenous lipophilic small molecules to facilitate their inactivation and excretion from the body. This represents approximately 35 % of all phase II metabolic transformations. Fatty acids and their oxidized eicosanoid derivatives can be metabolized by UGTs. F2-isoprostanes (F2-IsoPs) are eicosanoids formed from the free radical oxidation of arachidonic acid. These molecules are potent vasoconstrictors and are widely used as biomarkers of endogenous oxidative damage. An increasing body of evidence demonstrates the efficacy of measuring the β-oxidation metabolites of F2-IsoPs rather than the unmetabolized F2-IsoPs to quantify oxidative damage in certain settings. Yet, the metabolism of F2-IsoPs is incompletely understood. This study sought to identify and characterize novel phase II metabolites of 15-F2t-IsoP and 5-epi-5-F2t-IsoP, two abundantly produced F2-IsoPs, in human liver microsomes (HLM). Utilizing liquid chromatography-mass spectrometry, we demonstrated that glucuronide conjugates are the major metabolites of these F2-IsoPs in HLM. Further, we showed that these molecules are metabolized by specific UGT isoforms. 15-F2t-IsoP is metabolized by UGT1A3, 1A9, and 2B7, while 5-epi-5-F2t-IsoP is metabolized by UGT1A7, 1A9, and 2B7. We identified, for the first time, the formation of intact glucuronide F2-IsoPs in human urine and showed that F2-IsoP glucuronidation is reduced in people supplemented with eicosapentaenoic and docosahexaenoic acids for 12 weeks. These studies demonstrate that endogenous F2-IsoP levels can be modified by factors other than redox mechanisms
Multifaceted intervention to decrease the rate of severe postpartum haemorrhage: the PITHAGORE6 cluster-randomised controlled trial.: Intervention to decrease severe postpartum haemorrhage
International audienceOBJECTIVE: Decreasing the prevalence of severe postpartum haemorrhages (PPH) is a major obstetrical challenge. These are often considered to be associated with substandard initial care. Strategies to increase the appropriateness of early management of PPH must be assessed. We tested the hypothesis that a multifaceted intervention aimed at increasing the translation into practice of a protocol for early management of PPH, would reduce the incidence of severe PPH. DESIGN: Cluster-randomised trial. POPULATION: 106 maternity units in six French regions. METHODS: Maternity units were randomly assigned to receive the intervention, or to have the protocol passively disseminated. The intervention combined outreach visits to discuss the protocol in each local context, reminders, and peer reviews of severe incidents, and was implemented in each maternity hospital by a team pairing an obstetrician and a midwife. MAIN OUTCOME MEASURES: The primary outcome was the incidence of severe PPH, defined as a composite of one or more of: transfusion, embolisation, surgical procedure, transfer to intensive care, peripartum haemoglobin decrease of 4 g/dl or more, death. The main secondary outcomes were PPH management practices. RESULTS: The mean rate of severe PPH was 1.64% (SD 0.80) in the intervention units and 1.65% (SD 0.96) in control units; difference not significant. Some elements of PPH management were applied more frequently in intervention units-help from senior staff (P = 0.005), or tended to - second-line pharmacological treatment (P = 0.06), timely blood test (P = 0.09). CONCLUSION: This educational intervention did not affect the rate of severe PPH as compared with control units, although it improved some practices
Innate immunity, assessed by plasma NO measurements, is not suppressed during the incubation fast in eiders
Immunity is hypothesized to share limited resources with other physiological
functions and may mediate life history trade-offs, for example between
reproduction and survival. However, vertebrate immune defense is a complex
system that consists of three components. To date, no study has assessed all of
these components for the same animal model and within a given situation.
Previous studies have determined that the acquired immunity of common eiders
(Somateria mollissima) is suppressed during incubation. The present paper aims
to assess the innate immune response in fasting eiders in relation to their
initial body condition. Innate immunity was assessed by measuring plasma nitric
oxide (NO) levels, prior to and after injection of lipopolysaccharides (LPS), a
method which is easily applicable to many wild animals. Body condition index
and corticosterone levels were subsequently determined as indicators of body
condition and stress level prior to LPS injection. The innate immune response
in eiders did not vary significantly throughout the incubation period. The
innate immune response of eiders did not vary significantly in relation to
their initial body condition but decreased significantly when corticosterone
levels increased. However, NO levels after LPS injection were significantly and
positively related to initial body condition, while there was a significant
negative relationship with plasma corticosterone levels. Our study suggests
that female eiders preserve an effective innate immune response during
incubation and this response might be partially determined by the initial body
condition
Medieval coastal Syrian vegetation patterns in the principality of Antioch
The coastal area of Jableh, in the vicinity of the Saladin and Al-Marquab castles, is a fertile alluvial plain located on the northwestern part of Syria, in what was once the crusader Principality of Antioch. In order to detail the coastal environment during the crusader period in the Middle East, palynological analyses have been conducted on the underlying coastal-alluvial deposits. The recovered sediments represent a continuous record of the environmental history of the area spanning a c. AD 850—1850 cal. yr period, from the Muslim Era up to and including the late Ottoman times. During the local crusader period (AD 1100—1270), the area was dominated by an arborescent mattoral mixed with a xerophytic shrub-steppe. The alluvial plain was slightly waterlogged and colonized by a wetland meadow with an open vegetation of steppe-like character on bare surfaces and fresh arable soils. The riparian and open deciduous riverine forests were weakly developed. Signs of agricultural activities are mainly recorded for the High Medieval period (AD 1000—1300), with an increase of vineyards in the coastal area. Since c. AD 1250 cal. yr until the end of the crusader period, agricultural activities never reached the same intensity as during the Mameluke Sultanate and the Ottoman Empire
Bayesian model and selection signature analyses reveal risk factors for canine atopic dermatitis
Canine atopic dermatitis is an inflammatory skin disease with clinical similarities to human atopic dermatitis. Several dog breeds are at increased risk for developing this disease but previous genetic associations are poorly defined. To identify additional genetic risk factors for canine atopic dermatitis, we here apply a Bayesian mixture model adapted for mapping complex traits and a cross-population extended haplotype test to search for disease-associated loci and selective sweeps in four dog breeds at risk for atopic dermatitis. We define 15 associated loci and eight candidate regions under selection by comparing cases with controls. One associated locus is syntenic to the major genetic risk locus (Filaggrin locus) in human atopic dermatitis. One selection signal in common type Labrador retriever cases positions across the TBC1D1 gene (body weight) and one signal of selection in working type German shepherd controls overlaps the LRP1B gene (brain), near the KYNU gene (psoriasis). In conclusion, we identify candidate genes, including genes belonging to the same biological pathways across multiple loci, with potential relevance to the pathogenesis of canine atopic dermatitis. The results show genetic similarities between dog and human atopic dermatitis, and future across-species genetic comparisons are hereby further motivated
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