1,140 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.

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    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

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    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)

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    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

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    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

    Innate immunity, assessed by plasma NO measurements, is not suppressed during the incubation fast in eiders

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    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

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    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

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    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

    Logarithmic Corrections to Extremal Black Hole Entropy from Quantum Entropy Function

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    We evaluate the one loop determinant of matter multiplet fields of N=4 supergravity in the near horizon geometry of quarter BPS black holes, and use it to calculate logarithmic corrections to the entropy of these black holes using the quantum entropy function formalism. We show that even though individual fields give non-vanishing logarithmic contribution to the entropy, the net contribution from all the fields in the matter multiplet vanishes. Thus logarithmic corrections to the entropy of quarter BPS black holes, if present, must be independent of the number of matter multiplet fields in the theory. This is consistent with the microscopic results. During our analysis we also determine the complete spectrum of small fluctuations of matter multiplet fields in the near horizon geometry.Comment: LaTeX file, 52 pages; v2: minor corrections, references adde

    Six-Month Survival After Extracorporeal Membrane Oxygenation for Severe COVID-19

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    Objectives: The authors evaluated the outcome of adult patients with coronavirus disease 2019 (COVID-19)-related acute respiratory distress syndrome (ARDS) requiring the use of extracorporeal membrane oxygenation (ECMO). Design: Multicenter retrospective, observational study. Setting: Ten tertiary referral university and community hospitals. Participants: Patients with confirmed severe COVID-19-related ARDS. Interventions: Venovenous or venoarterial ECMO. Measurements and Main Results: One hundred thirty-two patients (mean age 51.1 +/- 9.7 years, female 17.4%) were treated with ECMO for confirmed severe COVID-19-related ARDS. Before ECMO, the mean Sequential Organ Failure Assessment score was 10.1 +/- 4.4, mean pH was 7.23 +/- 0.09, and mean PaO2/fraction of inspired oxygen ratio was 77 +/- 50 mmHg. Venovenous ECMO was adopted in 122 patients (92.4%) and venoarterial ECMO in ten patients (7.6%) (mean duration, 14.6 +/- 11.0 days). Sixty-three (47.7%) patients died on ECMO and 70 (53.0%) during the index hospitalization. Six-month all-cause mortality was 53.0%. Advanced age (per year, hazard ratio [HR] 1.026, 95% CI 1.000-1-052) and low arterial pH (per unit, HR 0.006, 95% CI 0.000-0.083) before ECMO were the only baseline variables associated with increased risk of six-month mortality. Conclusions: The present findings suggested that about half of adult patients with severe COVID-19 -related ARDS can be managed successfully with ECMO with sustained results at six months. Decreased arterial pH before ECMO was associated significantly with early mortality. Therefore, the authors hypothesized that initiation of ECMO therapy before severe metabolic derangements subset may improve survival rates significantly in these patients. These results should be viewed in the light of a strict patient selection policy and may not be replicated in patients with advanced age or multiple comorbidities. (C) 2021 The Authors. Published by Elsevier Inc.Peer reviewe
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