2,230 research outputs found
Simonsenia aveniformis sp nov (Bacillariophyceae), molecular phylogeny and systematics of the genus, and a new type of canal raphe system
The genus Simonsenia is reviewed and S. aveniformis described as new for science by light and electron microscopy. The new species originated from estuarine environments in southern Iberia (Atlantic coast) and was isolated into culture. In LM, Simonsenia resembles Nitzschia, with bridges (fibulae) beneath the raphe, which is marginal. It is only electron microscope (EM) examination that reveals the true structure of the raphe system, which consists of a raphe canal raised on a keel (wing), supported by rib like braces (fenestral bars) and tube-like portulae; between the portulae the keel is perforated by open windows (fenestrae). Based on the presence of portulae and a fenestrated keel, Simonsenia has been proposed to be intermediate between Bacillariaceae and Surirellaceae. However, an rbcL phylogeny revealed that Simonsenia belongs firmly in the Bacillariaceae, with which it shares a similar chloroplast arrangement, rather than in the Surirellaceae. Lack of homology between the surirelloid and simonsenioid keels is reflected in subtle differences in the morphology and ontogeny of the portulae and fenestrae. The diversity of Simonsenia has probably been underestimated, particularly in the marine environment.Polish National Science Centre in Cracow within the Maestro program [N 2012/04/A/ST10/00544]; Sciences and Technologies Foundation-FCT (Portugal) [SFRH/BD/62405/2009]info:eu-repo/semantics/publishedVersio
Distant X-ray Galaxies: Insights from the Local Population
A full understanding of the origin of the hard X-ray background requires a
complete and accurate census of the distant galaxies that produce it.
Unfortunately, distant X-ray galaxies tend to be very faint at all wavelengths,
which hinders efforts to perform this census. This chapter discusses the
insights that can be obtained through comparison of the distant population to
local X-ray galaxies, whose properties are well characterized. Such comparisons
will ultimately aid investigations into the cosmic evolution of supermassive
black holes and their environments.Comment: 19 pages, 10 figures, to appear as Chapter 7 in "Supermassive Black
Holes in the Distant Universe" (2004), ed. A. J. Barger, Kluwer Academic
Publishers, in pres
Superpulsed low-level laser therapy protects skeletal muscle of mdx mice against damage, inflammation and morphological changes delaying dystrophy progression.
Aim: To evaluate the effects of preventive treatment with low-level laser therapy (LLLT) on progression of dystrophy in mdx mice. Methods: Ten animals were randomly divided into 2 experimental groups treated with superpulsed LLLT (904 nm, 15 mW, 700 Hz, 1 J) or placebo-LLLT at one point overlying the tibialis anterior muscle (bilaterally) 5 times per week for 14 weeks (from 6th to 20th week of age). Morphological changes, creatine kinase (CK) activity and mRNA gene expression were assessed in animals at 20th week of age. Results: Animals treated with LLLT showed very few morphological changes in skeletal muscle, with less atrophy and fibrosis than animals treated with placebo-LLLT. CK was significantly lower (p = 0.0203) in animals treated with LLLT (864.70 U.l−1, SEM 226.10) than placebo (1708.00 U.l−1, SEM 184.60). mRNA gene expression of inflammatory markers was significantly decreased by treatment with LLLT (p<0.05): TNF-α (placebo-control = 0.51 µg/µl [SEM 0.12], - LLLT = 0.048 µg/µl [SEM 0.01]), IL-1β (placebo-control = 2.292 µg/µl [SEM 0.74], - LLLT = 0.12 µg/µl [SEM 0.03]), IL-6 (placebo-control = 3.946 µg/µl [SEM 0.98], - LLLT = 0.854 µg/µl [SEM 0.33]), IL-10 (placebo-control = 1.116 µg/µl [SEM 0.22], - LLLT = 0.352 µg/µl [SEM 0.15]), and COX-2 (placebo-control = 4.984 µg/µl [SEM 1.18], LLLT = 1.470 µg/µl [SEM 0.73]). Conclusion: Irradiation of superpulsed LLLT on successive days five times per week for 14 weeks decreased morphological changes, skeletal muscle damage and inflammation in mdx mice. This indicates that LLLT has potential to decrease progression of Duchenne muscular dystrophy
A decision support system for water quality issues in the Manzanares River (Madrid, Spain)
The Manzanares River, located in Madrid (Spain), is the main water supplier of a highly populated region,
and it also receives wastewater from the same area. The effluents of eight Waste Water Treatment Plants
(WWTPs) downstream of the river, which represent 90% of the flow in the middle and lower parts of the
river, are the primary sources of water pollution. Although the situation has improved slightly in the last two
years, the water in the river is highly polluted, making it uninhabitable for aquatic life. Water quality
modelling is typically used to assess the effect of treatment improvements in water bodies. In this work, the
GESCAL module of the Aquatool Decision Support System Shell was used to simulate water quality in the
Manzanares River. GESCAL is appropriate for modelling in an integrated way water quality for whole water
resources systems, including reservoirs and rivers. A model was built that simulates conductivity,
phosphorous, carbonaceous organic matter, dissolved oxygen, organic nitrogen, ammonia, and nitrates.
The period from October 2006 to September 2008 was selected for calibration due to the many treatment
modifications that occurred during this time. An earlier and longer period, from October 2000 to September
2006, was used for validation. In addition, a daily model was used to analyse the robustness of the GESCAL
model. Once the GESCAL model was validated, different scenarios were considered and simulated. First,
different combinations of nutrient elimination among the different WWTPs were simulated, leading to the
conclusion that investments have to focus on three of the proposed WWTPs. Moreover, these treatments will
not be sufficient to maintain fish habitat conditions at all times. Additional measures, such as the increment
of the flow in the river or oxygen injection, were simulated. Incrementing the flow of the Manzanares River
has been shown to be an efficient means of increasing water quality, but this implies an increment in the risk
of water scarcity situations in the Madrid water supply system.
© 2010 Elsevier B.V. All rights reserved.This work has been supported by the Spanish Ministry of Science and Innovation through the project Consolider-Ingenio 2010 CSD2009-00065.Paredes Arquiola, J.; Andreu Álvarez, J.; Solera Solera, A. (2010). A decision support system for water quality issues in the Manzanares River (Madrid, Spain). Science of the Total Environment. 408:2576-2589. https://doi.org/10.1016/j.scitotenv.2010.02.037S2576258940
EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 08, Revision 5 (FGE.08Rev5): Aliphatic and alicyclic mono-, di-, tri-, and polysulphides with or without additional oxygenated functional groups from chemical groups 20 and 30
<p>The CEF Panel of the European Food Safety Authority was requested to evaluate 80 flavouring substances in the Flavouring Group Evaluation 08, Revision 4, using the Procedure in Commission Regulation (EC) No 1565/2000. Since the publication of the last revision of this FGE, the EFSA has been requested to evaluate additional toxicological data submitted for two flavouring substances, one substance 2,5-dihydroxy-2,5-dimethyl-1,4-dithiane [FL-no: 15.006], which support the evaluation of the candidate substance 2,5-dihydroxy-1,4-dithiane [FL-no: 15.134] and one on the candidate substance spiro(2,4-dithia-1-methyl-8-oxabicyclo[3.3.0]octane-3,3’-(1’-oxa-2’-methyl)-cyclopentane) and spiro(2,4-dithia-6-methyl-7-oxabicyclo[3.3.0]octane-3,3’-(1’-oxa-2’-methyl)-cyclopentane) [FL-no: 15.007], which have been included in the present revision of FGE.08. For the substances methyl methanethiosulphonate [FL-no: 12.159], 2-methylbutane-2-thiol [FL-no: 12.172], 2-methylpropane-2-thiol [FL-no: 12.174], ethyl-2-mercapto-2-methyl propanoate [FL-no: 12.304] and 2,4,4-trimethyl-1,3-oxathiane [FL-no: 16.057] there is an indication of a genotoxic potential in vitro. Therefore, without further genotoxicity data, the Panel concluded that the Procedure could not be applied to these five substances. For four substances, 3-mercaptooctanal [FL-no: 12.268], 3-mercaptodecanal [FL-no: 12.269], methanedithiol diacetate [FL-no: 12.271] and 3,5-dimethyl-1,2-dithiolane-4-one [FL-no: 12.295] no data on use as flavouring substances in Europe are available and no intake figures could be calculated, which preclude the evaluation of the four substances using the Procedure. The remaining 71 substances were evaluated through a stepwise approach that integrates information on the structure-activity relationships, intake from current uses, toxicological threshold of concern, and available data on metabolism and toxicity. The Panel concluded that 59 substances do not rise safety concerns at their levels of dietary intake, estimated on the basis of the MSDI approach. For 12 substances [FL-no: 12.093, 12.094, 12.097, 12.100, 12.112, 12.116, 12.120, 12.164, 12.167, 12.199, 15.102 and 15.125], evaluated through the Procedure, no appropriate NOAEL was available and additional data are required. The specifications for the materials of commerce have also been considered and for three substances, information on the specifications is lacking.</p>
Multiple reassortment events in the evolutionary history of H1N1 influenza A virus since 1918
The H1N1 subtype of influenza A virus has caused substantial morbidity and mortality in humans, first documented in the global pandemic of 1918 and continuing to the present day. Despite this disease burden, the evolutionary history of the A/H1N1 virus is not well understood, particularly whether there is a virological basis for several notable epidemics of unusual severity in the 1940s and 1950s. Using a data set of 71 representative complete genome sequences sampled between 1918 and 2006, we show that segmental reassortment has played an important role in the genomic evolution of A/H1N1 since 1918. Specifically, we demonstrate that an A/H1N1 isolate from the 1947 epidemic acquired novel PB2 and HA genes through intra-subtype reassortment, which may explain the abrupt antigenic evolution of this virus. Similarly, the 1951 influenza epidemic may also have been associated with reassortant A/H1N1 viruses. Intra-subtype reassortment therefore appears to be a more important process in the evolution and epidemiology of H1N1 influenza A virus than previously realized
The Evolution of Bat Vestibular Systems in the Face of Potential Antagonistic Selection Pressures for Flight and Echolocation
PMCID: PMC3634842This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
A central mechanism of analgesia in mice and humans lacking the sodium channel NaV1.7
Deletion of SCN9A encoding the voltage-gated sodium channel NaV1.7 in humans leads to profound pain insensitivity and anosmia. Conditional deletion of NaV1.7 in sensory neurons of mice also abolishes pain, suggesting that the locus of analgesia is the nociceptor. Here we demonstrate, using in vivo calcium imaging and extracellular recording, that NaV1.7 knockout mice have essentially normal nociceptor activity. However, synaptic transmission from nociceptor central terminals in the spinal cord is greatly reduced by an opioid-dependent mechanism. Analgesia is also reversed substantially by central but not peripheral application of opioid antagonists. In contrast, the lack of neurotransmitter release from olfactory sensory neurons is opioid independent. Male and female humans with NaV1.7-null mutations show naloxone-reversible analgesia. Thus, inhibition of neurotransmitter release is the principal mechanism of anosmia and analgesia in mouse and human Nav1.7-null mutants
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