174 research outputs found
Effects of solar activity on noise in CALIOP profiles above the South Atlantic Anomaly
We show that nighttime dark noise measurements from the spaceborne lidar
CALIOP contain valuable information about the evolution of upwelling
high-energy radiation levels. Above the South Atlantic Anomaly (SAA), CALIOP
dark noise levels fluctuate by ±6% between 2006 and 2013, and follow
the known anticorrelation of local particle flux with the 11-year cycle of
solar activity (with a 1-year lag). By analyzing the geographic distribution
of noisy profiles, we are able to reproduce known findings about the SAA
region. Over the considered period, it shifts westward by
0.3° year<sup>−1</sup>, and changes in size by 6° meridionally and
2° zonally, becoming larger with weaker solar activity. All results are
in strong agreement with previous works. We predict SAA noise levels will
increase anew after 2014, and will affect future spaceborne lidar missions
most near 2020
Effect of apoA-I on cholesterol release and apoE secretion in human mature adipocytes
<p>Abstract</p> <p>Background</p> <p>The risk of cardiovascular disease is inversely correlated to level of plasma HDL-c. Moreover, reverse cholesterol transport (RCT) from peripheral tissues to the liver is the most widely accepted mechanism linked to the anti-atherosclerotic activity of HDL. The apolipoprotein A-I (apoA-I) and the ABC transporters play a key role in this process.</p> <p>Adipose tissue constitutes the body's largest pool of free cholesterol. The adipose cell could therefore be regarded as a key factor in cholesterol homeostasis. The present study investigates the capacity of primary cultures of mature human adipocytes to release cholesterol and explores the relationships between apoA-I, ABCA1, and apoE as well as the signaling pathways that could be potentially involved.</p> <p>Results</p> <p>We demonstrate that apoA-I induces a strong increase in cholesterol release and apoE secretion from adipocytes, whereas it has no transcriptional effect on ABCA1 or apoE genes. Furthermore, brefeldin A (BFA), an intracellular trafficking inhibitor, reduces basal cholesterol and apoE secretion, but does not modify induction by apoA-I. The use of statins also demonstrates that apoA-I stimulated cholesterol release is independent of HMG-CoA reductase activation.</p> <p>Conclusion</p> <p>Our work highlights the fact that adipose tissue, and particularly adipocytes, may largely contribute to RCT <it>via </it>a mechanism specifically regulated within these cells. This further supports the argument that adipose tissue must be regarded as a major factor in the development of cardiovascular diseases, in particular atherosclerosis.</p
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Attempted re-establishment of a sooty tern Onychoprion fuscatus breeding colony on Denis Island, Seychelles
Seychelles supports around three million nesting pairs of sooty terns. However, there have been recent declines and the colonies continue to face ongoing threats from habitat change and excessive commercial harvesting of their eggs, as well as potential threats by commercial fishing and climate change. A possible method to counter these threats is to re-establish breeding colonies on islands from which they have disappeared. An attempt was made to attract birds to a previously occupied island through habitat management, decoy birds and playback of recorded sooty tern calls. Habitat preparation involved predator eradication and tree removal to provide open ground with bare sandy areas and low herb vegetation. Overflying birds were attracted by broadcast calls, with some circling over and landing among the decoys. Large three-dimensional plastic models were superior to other models presented. This study demonstrated that large numbers of birds can be attracted by these means and that the birds then undertook behaviour associated with breeding, including egg laying by a few birds. However, after five seasons a breeding colony has not yet been established; one possible cause is the emergence of unexpected egg predators, common moorhen Gallinula chloropus and common myna Acridotheres tristis
Maïdo observatory: a new high-altitude station facility at Reunion Island (21° S, 55° E) for long-term atmospheric remote sensing and in situ measurements
Since the nineties, atmospheric measurement systems have been deployed at Reunion Island, mainly for monitoring the atmospheric composition in the framework of NDSC/NDACC (Network for the Detection of <i>Stratospheric</i> Change/Network for the Detection of Atmospheric Composition Change). The location of Reunion Island presents a great interest because there are very few multi-instrumented stations in the tropics and particularly in the southern hemisphere. In 2012, a new observatory was commissioned in Maïdo at 2200 m above sea level: it hosts various instruments for atmospheric measurements, including lidar systems, spectro-radiometers and in situ gas and aerosol measurements. <br><br> This new high-altitude Maïdo station provides an opportunity:<br> 1. to improve the performance of the optical instruments above the marine boundary layer, and to open new perspectives on upper troposphere and lower stratosphere studies;<br> 2. to develop in situ measurements of the atmospheric composition for climate change surveys, in a reference site in the tropical/subtropical region of the southern hemisphere;<br> 3. to offer trans-national access to host experiments or measurement campaigns for focused process studies
Palmitoylethanolamide exerts neuroprotective effects in mixed neuroglial cultures and organotypic hippocampal slices via peroxisome proliferator-activated receptor-α
<p>Abstract</p> <p>Background</p> <p>In addition to cytotoxic mechanisms directly impacting neurons, β-amyloid (Aβ)-induced glial activation also promotes release of proinflammatory molecules that may self-perpetuate reactive gliosis and damage neighbouring neurons, thus amplifying neuropathological lesions occurring in Alzheimer's disease (AD). Palmitoylethanolamide (PEA) has been studied extensively for its anti-inflammatory, analgesic, antiepileptic and neuroprotective effects. PEA is a lipid messenger isolated from mammalian and vegetable tissues that mimics several endocannabinoid-driven actions, even though it does not bind to cannabinoid receptors. Some of its pharmacological properties are considered to be dependent on the expression of peroxisome proliferator-activated receptors-α (PPARα).</p> <p>Findings</p> <p>In the present study, we evaluated the effect of PEA on astrocyte activation and neuronal loss in models of Aβ neurotoxicity. To this purpose, primary rat mixed neuroglial co-cultures and organotypic hippocampal slices were challenged with Aβ<sub>1-42 </sub>and treated with PEA in the presence or absence of MK886 or GW9662, which are selective PPARα and PPARγ antagonists, respectively. The results indicate that PEA is able to blunt Aβ-induced astrocyte activation and, subsequently, to improve neuronal survival through selective PPARα activation. The data from organotypic cultures confirm that PEA anti-inflammatory properties implicate PPARα mediation and reveal that the reduction of reactive gliosis subsequently induces a marked rebound neuroprotective effect on neurons.</p> <p>Conclusions</p> <p>In line with our previous observations, the results of this study show that PEA treatment results in decreased numbers of infiltrating astrocytes during Aβ challenge, resulting in significant neuroprotection. PEA could thus represent a promising pharmacological tool because it is able to reduce Aβ-evoked neuroinflammation and attenuate its neurodegenerative consequences.</p
Detoxifying effect of Nelumbo nucifera and Aegle marmelos on hematological parameters of Common Carp (Cyprinus carpio L.)
The objective of this study was to investigate the efficacy of Nelumbo nucifera and Aegle marmelos on common carp exposed to sub-lethal concentrations of combined heavy metals (5 ppm) under laboratory conditions. The fish were treated with Nelumbo nucifera (500 mg/kg bwt) and Aegle marmelos (500 mg/kgbwt) for 30 days as a dietary supplement. The blood biochemical parameters of the fish were evaluated by analyzing the level of red blood cells (RBC), packed cell volume (PCV), hemoglobin concentration, glucose, cholesterol, iron and copper. The findings of the present investigation showed significant increase in hemoglobin (p<0.001), RBC (p<0.01) and PCV (p<0.01) of herbal drug-treated groups compared with metal-exposed fish. Conversely, glucose and cholesterol level in blood of common carp showed significant reduction compared with heavy-metal-exposed groups. All the values measured in Nelumbo nucifera and Aegle marmelos treated fish were restored comparably to control fish. Our results confirmed that Nelumbo nucifera and Aegle marmelos provide a detoxification mechanism for heavy metals in common carp
Effects of fishery protection on biometry and genetic structure of two target sea cucumber species from the Mediterranean Sea
Sea cucumber fisheries are now occurring
in most of the tropical areas of the world, having
expanded from its origin in the central Indo-Pacific.
Due to the overexploitation of these resources and the
increasing demand from Asian countries, new target
species from Mediterranean Sea and northeastern
Atlantic Ocean are being caught. The fishery effects
on biometry and genetic structure of two target species
(Holothuria polii and H. tubulosa) from Turkey, were
assessed. The heaviest and largest individuals of H.
polii were found into the non-fishery area of Kusadasi,
also showing the highest genetic diversity. Similar
pattern was detected in H. tubulosa, but only the
weight was significantly higher in the protected area.
However, the observed differences on the fishery
effects between species, could be explained considering
the different percentage of catches (80% for H.
polii and 20% for H. tubulosa)
Early invasive vulvar squamous cell carcinoma arising in a woman with vulvar pemphigus vulgaris and systemic lupus erythematosus
Pemphigus vulgaris (PV) is an autoimmune blistering disease of the skin and mucous membranes. Genital involvement occurs when most other common sites are concurrently affected or are in remission. Systemic lupus erythematosus (SLE) is an autoimmune disease that may affect many parts of the body and the skin with occasional bullous lesions. Pemphigus vulgaris and SLE may be associated, albeit rarely. Here, we report the first case of a woman affected with SLE presenting with early invasive squamous cell carcinoma (SCC) arising from Pemphigus Vulgaris of the vulva
Global Diversity of Brittle Stars (Echinodermata: Ophiuroidea)
This review presents a comprehensive overview of the current status regarding the global diversity of the echinoderm class Ophiuroidea, focussing on taxonomy and distribution patterns, with brief introduction to their anatomy, biology, phylogeny, and palaeontological history. A glossary of terms is provided. Species names and taxonomic decisions have been extracted from the literature and compiled in The World Ophiuroidea Database, part of the World Register of Marine Species (WoRMS). Ophiuroidea, with 2064 known species, are the largest class of Echinodermata. A table presents 16 families with numbers of genera and species. The largest are Amphiuridae (467), Ophiuridae (344 species) and Ophiacanthidae (319 species). A biogeographic analysis for all world oceans and all accepted species was performed, based on published distribution records. Approximately similar numbers of species were recorded from the shelf (n = 1313) and bathyal depth strata (1297). The Indo-Pacific region had the highest species richness overall (825 species) and at all depths. Adjacent regions were also relatively species rich, including the North Pacific (398), South Pacific (355) and Indian (316) due to the presence of many Indo-Pacific species that partially extended into these regions. A secondary region of enhanced species richness was found in the West Atlantic (335). Regions of relatively low species richness include the Arctic (73 species), East Atlantic (118), South America (124) and Antarctic (126)
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