| 1. |
- Do Rego, Jean-Luc, et al.
(författare)
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Steroid biosynthesis within the frog brain : a model of neuroendocrine regulation
- 2009
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Ingår i: Annals of the New York Academy of Sciences. - : Wiley. - 0077-8923 .- 1749-6632. ; 1163, s. 83-92
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Tidskriftsartikel (refereegranskat)abstract
- There is now clear evidence that the brain, similar to the adrenal gland, gonads, and placenta, is a steroidogenic organ. Notably in the frog brain, the presence of various steroidogenic enzymes has been detected by immunohistochemistry in specific populations of neurons and/or glial cells. These steroidogenic enzymes are biologically active, as shown by the ability of brain tissue explants to convert [(3)H]pregnenolone into various radiolabeled steroids. The frog brain has also been extensively used as a model to study the mechanism of regulation of neurosteroidogenesis by neurotransmitters and neuropeptides. It has been demonstrated that the biosynthesis of neurosteroids is inhibited by gamma-aminobutyric acid (GABA), acting through GABA(A) receptors, and neuropeptide Y, acting through Y1 receptors, and is stimulated by the octadecaneuropeptide (ODN), acting through central-type benzodiazepine receptors, triakontatetraneuropeptide (TTN), acting through peripheral-type benzodiazepine receptors, and vasotocin, acting through V1a-like receptors. These data indicate that some of the neurophysiological effects of neurotransmitters and neuropeptides may be mediated through modulation of neurosteroid biosynthesis.
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| 2. |
- Larochelle, Jean, et al.
(författare)
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Effect of nitisinone (NTBC) treatment on the clinical course of hepatorenal tyrosinemia in Québec.
- 2012
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Ingår i: Molecular genetics and metabolism. - : Elsevier BV. - 1096-7206 .- 1096-7192. ; 107:1-2, s. 49-54
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Tidskriftsartikel (refereegranskat)abstract
- Hepatorenal tyrosinemia (HT1, fumarylacetoacetate hydrolase deficiency, MIM 276700) can cause severe hepatic, renal and peripheral nerve damage. In Québec, HT1 is frequent and neonatal HT1 screening is practiced. Nitisinone (NTBC, Orfadin ®) inhibits tyrosine degradation prior to the formation of toxic metabolites like succinylacetone and has been offered to HT1 patients in Québec since 1994.
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| 3. |
- Loisel, Julie, et al.
(författare)
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Insights and issues with estimating northern peatland carbon stocks and fluxes since the Last Glacial Maximum
- 2017
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Ingår i: Earth-Science Reviews. - : Elsevier BV. - 0012-8252 .- 1872-6828. ; 165, s. 59-80
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Forskningsöversikt (refereegranskat)abstract
- In this review paper, we identify and address key uncertainties related to four local and global controls of Holocene northern peatland carbon stocks and fluxes. First, we provide up-to-date estimates of the current northern peatland area (3.2 M km(2)) and propose a novel approach to reconstruct changes in the northern peatland area over time (Section 2). Second, we review the key methods and models that have been used to quantify total carbon stocks and methane emissions over time at the hemispheric scale, and offer new research directions to improve these calculations (Section 3). Our main proposed improvement relates to allocating different carbon stock and emission values for each of the two dominant vegetation assemblages (sedge and brown moss-dominated vs. Sphagnum-dominated peat). Third, we discuss and quantify the importance of basin heterogeneity in estimating peat volume at the local scale (Section 4.1). We also highlight the importance of age model selection when reconstructing carbon accumulation rates from a peat core (Section 4.2). Lastly, we introduce the role of biogeomorphological agents such as beaver activity in controlling carbon dynamics (Section 5.1) and review the newest research related to permafrost thaw (Section 5.2) and peat fire (Section 5.3) under climate change. Overall, this review summarizes new information from a broad range of peat-carbon studies, provides novel analysis of hemispheric-scale paleo datasets, and proposes new insights on how to translate peat-core data into carbon fluxes. It also identifies critical data gaps and research priorities, and many ways to consider and address them.
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| 4. |
- Mills, James A., et al.
(författare)
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Archiving Primary Data : Solutions for Long-Term Studies
- 2015
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Ingår i: Trends in Ecology & Evolution. - : Elsevier BV. - 0169-5347 .- 1872-8383. ; 30:10, s. 581-589
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Tidskriftsartikel (refereegranskat)abstract
- The recent trend for journals to require open access to primary data included in publications has been embraced by many biologists, but has caused apprehension amongst researchers engaged in long-term ecological and evolutionary studies. A worldwide survey of 73 principal investigators (PIs) with long-term studies revealed positive attitudes towards sharing data with the agreement or involvement of the PI, and 93% of PIs have historically shared data. Only 8% were in favor of uncontrolled, open access to primary data while 63% expressed serious concern. We present here their viewpoint on an issue that can have non-trivial scientific consequences. We discuss potential costs of public data archiving and provide possible solutions to meet the needs of journals and researchers.
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| 5. |
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| 6. |
- Pelletier, Stefan, et al.
(författare)
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Vanadium oxide and a sharp onset of cold-trapping on a giant exoplanet
- 2023
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Ingår i: Nature. - 0028-0836. ; 619:7970, s. 491-494
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Tidskriftsartikel (refereegranskat)abstract
- The abundance of refractory elements in giant planets can provide key insights into their formation histories1. Owing to the low temperatures of the Solar System giants, refractory elements condense below the cloud deck, limiting sensing capabilities to only highly volatile elements2. Recently, ultra-hot giant exoplanets have allowed for some refractory elements to be measured, showing abundances broadly consistent with the solar nebula with titanium probably condensed out of the photosphere3,4. Here we report precise abundance constraints of 14 major refractory elements on the ultra-hot giant planet WASP-76b that show distinct deviations from proto-solar and a sharp onset in condensation temperature. In particular, we find nickel to be enriched, a possible sign of the accretion of the core of a differentiated object during the evolution of the planet. Elements with condensation temperatures below 1,550 K otherwise closely match those of the Sun5 before sharply transitioning to being strongly depleted above 1,550 K, which is well explained by nightside cold-trapping. We further unambiguously detect vanadium oxide on WASP-76b, a molecule long suggested to drive atmospheric thermal inversions6, and also observe a global east–west asymmetry7 in its absorption signals. Overall, our findings indicate that giant planets have a mostly stellar-like refractory elemental content and suggest that temperature sequences of hot Jupiter spectra can show abrupt transitions wherein a mineral species is either present or completely absent if a cold trap exists below its condensation temperature8.
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