1,930 research outputs found
Global environmental changes: setting priorities for Latin American coastal habitats.
The definitive version is available at www.blackwell-synergy.comThe Intergovernmental Panel for Climate Change (IPCC) reports that Global Environmental Changes (GEC) are occurring quicker than at any other time over the last 25 million years and impacting upon marine environments (Bellard et al., 2012). There is overwhelming evidence showing that GEC are affecting both the quality and quantity of the goods and services provided by a wide range of marine ecosystems. In order to discuss regional preparedness for global environmental changes, a workshop was held in Ilhabela, Brazil (22- 26 April 2012) entitled "Evaluating the Sensitivity of Central and South American Benthic Communities to Global Environmental Changes" that drew together scientists from ten Latin American and three European countries. © 2013 Blackwell Publishing Ltd
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Pulse control protocols for preserving coherence in dipolar-coupled nuclear spin baths.
Coherence of solid state spin qubits is limited by decoherence and random fluctuations in the spin bath environment. Here we develop spin bath control sequences which simultaneously suppress the fluctuations arising from intrabath interactions and inhomogeneity. Experiments on neutral self-assembled quantum dots yield up to a five-fold increase in coherence of a bare nuclear spin bath. Numerical simulations agree with experiments and reveal emergent thermodynamic behaviour where fluctuations are ultimately caused by irreversible conversion of coherence into many-body quantum entanglement. Simulations show that for homogeneous spin baths our sequences are efficient with non-ideal control pulses, while inhomogeneous bath coherence is inherently limited even under ideal-pulse control, especially for strongly correlated spin-9/2 baths. These results highlight the limitations of self-assembled quantum dots and advantages of strain-free dots, where our sequences can be used to control the fluctuations of a homogeneous nuclear spin bath and potentially improve electron spin qubit coherence
PreImplantation Factor (PIF) promotes HLA-G, -E, -F, -C expression in JEG-3 choriocarcinoma cells and endogenous progesterone activity
BACKGROUND: Pregnancy success requires mandatory maternal tolerance of the semi/allogeneic embryo involving embryo-derived signals. Expression levels of PreImplantation Factor (PIF), a novel peptide secreted by viable embryos, correlate with embryo development, and its early detection in circulation correlates with a favourable pregnancy outcome. PIF enhances endometrial receptivity to promote embryo implantation. Via the p53 pathway, it increases trophoblast invasion, improving cell survival / immune privilege. PIF also reduces spontaneous and LPS-induced foetal death in immune naïve murine model.
AIMS: To examine if PIF affects gene expression of human leukocyte antigen (HLA)-G, -E -F and -C in JEG-3 choriocarcinoma cells, and to examine the influence of PIF on local progesterone activity.
Methods: PIF and progesterone (P4) effects on JEG-3 cells surface and intracellular HLA molecules was tested using monoclonal antibodies, flow cytometry, and Western blotting. PIF and IL17 effects on P4 and cytokines secretion was determined by ELISA. PIF and P4 effects on JEG-3 cells proteome was examined using 2D gel staining followed by spot analysis, mass spectrometry and bioinformatic analysis.
RESULTS: In cytotrophoblastic JEG-3 cells PIF increased intracellular expression of HLA-G, HLA-F, HLA-E and HLA-C and surface expression of HLA-G, HLA-E and HLA-C in dose and time dependent manner. In case of HLA-E, F confirmed also by Western blotting. Proteome analysis confirmed an increase in HLA-G, pro-tolerance FOXP3+ regulatory T cells (Tregs), coagulation factors and complement regulator. In contrast, PIF reduced PRDX2 and HSP70s to negate oxidative stress and protein misfolding. PIF enhanced local progesterone activity, increasing steroid secretion and the receptor protein. It also promoted the secretion of the Th1/Th2 cytokines (IL-10, IL-1β, IL-8, GM-CSF and TGF-β1), resulting in improved maternal signalling.
CONCLUSION: PIF can generate a pro-tolerance milieu by enhancing the expression of HLA molecules and by amplifying endogenous progesterone activity.
A Fast-Track clinical trial for autoimmune disease has been satisfactorily completed. The acquired data warrants PIF use for the treatment of early pregnancy disorders
Bound states of spin-half particles in a static gravitational field close to the black hole field
We consider the bound-state energy levels of a spin-1/2 fermion in the
gravitational field of a near-black hole object. In the limit that the metric
of the body becomes singular, all binding energies tend to the rest-mass energy
(i.e. total energy approaches zero). We present calculations of the ground
state energy for three specific interior metrics (Florides, Soffel and
Schwarzschild) for which the spectrum collapses and becomes quasi-continuous in
the singular metric limit. The lack of zero or negative energy states prior to
this limit being reached prevents particle pair production occurring.
Therefore, in contrast to the Coulomb case, no pairs are produced in the
non-singular static metric. For the Florides and Soffel metrics the singularity
occurs in the black hole limit, while for the Schwarzschild interior metric it
corresponds to infinite pressure at the centre. The behaviour of the energy
level spectrum is discussed in the context of the semi-classical approximation
and using general properties of the metric.Comment: 16 pages, 6 Figures. Submitted to General Relativity and Gravitatio
Evaluation of the SPOT™ Photoscreener’s Efficacy for Detecting Amblyopia Risk Factors Compared to Optometrists’ Examinations in 305 South Dakota Children
Purpose: This study sought to further validate the efficacy of the SPOTTM photoscreener version (v) 3.0.0500 as a screening device for amblyopia risk factors (ARF).
Methods: This was a cross-sectional study from five different western South Dakota outpatient clinics. Data from 610 eyes of 305 children aged 6 months to 13.5 years collected between July 2018 to September 2018 were analyzed, using both the out-of-box referral criteria and the 2013 American Association for Pediatric Ophthalmology and Strabismus (AAPOS) referral criteria. Optometrist (eye care provider or ECP) cycloplegia practice patterns were deferred to each clinics’ specific protocols. Power vector and Bland-Altman plot analyses were performed.
Results: The average age of the 305 children in the study population is 99.6 months (~8.3 years), with a total of 42% of these subjects receiving no dilating drops prior to testing. From these cases, the SPOTTM v3.0.0500 photoscreener evaluation parameters for detecting ARFs using the out-of-box referral criteria yielded an overall sensitivity (SN) of 95.2%, specificity (SP) of 91.9%, positive predictive value (PPV) of 81.6%, and negative predictive value (NPV) of 98.1%; the SPOTTM v3.0.0500 photoscreener evaluation parameters for detecting ARFs using the 2013 AAPOS referral criteria yielded an overall SN of 96.3%, SP of 92.4%, PPV of 82.1%, and NPV of 98.6%.
Conclusions: With SN and NPV values exceeding 95%, this study supports the efficacy of the SPOTTM v3.0.0500 photoscreener as a pediatric screening device to detect ARFs. Power vector analyses help to provide further objective comparisons of refractive measurements between photoscreening devices and refractive examinations
A new conceptual framework for the transformation of groundwater dissolved organic matter
Groundwater comprises 95% of the liquid fresh water on Earth and contains a diverse mix of dissolved organic matter (DOM) molecules which play a significant role in the global carbon cycle. Currently, the storage times and degradation pathways of groundwater DOM are unclear, preventing an accurate estimate of groundwater carbon sources and sinks for global carbon budgets. Here we reveal the transformations of DOM in aging groundwater using ultra-high resolution mass spectrometry combined with radiocarbon dating. Long-term anoxia and a lack of photodegradation leads to the removal of oxidised DOM and a build-up of both reduced photodegradable formulae and aerobically biolabile formulae with a strong microbial signal. This contrasts with the degradation pathway of DOM in oxic marine, river, and lake systems. Our findings suggest that processes such as groundwater extraction and subterranean groundwater discharge to oceans could result in up to 13 Tg of highly photolabile and aerobically biolabile groundwater dissolved organic carbon released to surface environments per year, where it can be rapidly degraded. These findings highlight the importance of considering groundwater DOM in global carbon budgets
TOM40 Mediates Mitochondrial Dysfunction Induced by α-Synuclein Accumulation in Parkinson's Disease.
Alpha-synuclein (α-Syn) accumulation/aggregation and mitochondrial dysfunction play prominent roles in the pathology of Parkinson's disease. We have previously shown that postmortem human dopaminergic neurons from PD brains accumulate high levels of mitochondrial DNA (mtDNA) deletions. We now addressed the question, whether alterations in a component of the mitochondrial import machinery -TOM40- might contribute to the mitochondrial dysfunction and damage in PD. For this purpose, we studied levels of TOM40, mtDNA deletions, oxidative damage, energy production, and complexes of the respiratory chain in brain homogenates as well as in single neurons, using laser-capture-microdissection in transgenic mice overexpressing human wildtype α-Syn. Additionally, we used lentivirus-mediated stereotactic delivery of a component of this import machinery into mouse brain as a novel therapeutic strategy. We report here that TOM40 is significantly reduced in the brain of PD patients and in α-Syn transgenic mice. TOM40 deficits were associated with increased mtDNA deletions and oxidative DNA damage, and with decreased energy production and altered levels of complex I proteins in α-Syn transgenic mice. Lentiviral-mediated overexpression of Tom40 in α-Syn-transgenic mice brains ameliorated energy deficits as well as oxidative burden. Our results suggest that alterations in the mitochondrial protein transport machinery might contribute to mitochondrial impairment in α-Synucleinopathies
Cross-Atlantic modification and validation of the A Tool to assess quality of life in idiopathic pulmonary fibrosis (ATAQ-IPF-cA)
Rationale: The A Tool to Assess Quality of Life in Idiopathic Pulmonary Fibrosis (ATAQ-IPF) was developed in the USA to assess health-related quality of life in patients with IPF. It is likely that some of the original ATAQ-IPF items perform differently when applied in different countries. This paper reports results of a study conducted to identify the need to refine the content of the ATAQ-IPF to minimise cross-country bias between the USA and the UK.
Methods: The ATAQ-IPF and other study measures were completed by patients attending specialist IPF clinics in the USA and UK. Rasch analysis was used to determine which items performed differently across countries (USA vs UK) and refine the original ATAQ-IPF to an instrument without cross-country bias (ATAQ-IPF-cA). Preliminary validation of the modified instrument was examined by assessing correlations between ATAQ-IPF-cA scores and scores from dyspnoea-specific patient-reported outcome (PRO) measures.
Results: 139 patients with IPF (USA=74; UK=65) participated in the study. A total of 41 items and 4 domains were removed from the original, 86-item instrument to yield the 43 items and 10 domains of the ATAQ-IPF-cA. Each domain had good fit to the Rasch model, internal consistency was comparable to the corresponding domains for the original ATAQ-IPF, and validity was supported by significant correlations between its scores and scores from dyspnoea-specific PROs.
Conclusions: The reliability and validity of the substantially shortened ATAQ-IPF-cA are acceptable and comparable to the original instrument. We recommend use of the ATAQ-IPF-cA in IPF studies in which participants are enrolled from the USA and UK
Transcriptome analysis of the central nervous system of the mollusc Lymnaea stagnalis
Background: The freshwater snail Lymnaea stagnalis (L. stagnalis) has served as a successful model for studies in the field of Neuroscience. However, a serious drawback in the molecular analysis of the nervous system of L. stagnalis has been the lack of large-scale genomic or neuronal transcriptome information, thereby limiting the use of this unique model. Results: In this study, we report 7,712 distinct EST sequences (median length: 847 nucleotides) of a normalized L. stagnalis central nervous system (CNS) cDNA library, resulting in the largest collection of L. stagnalis neuronal transcriptome data currently available. Approximately 42% of the cDNAs can be translated into more than 100 consecutive amino acids, indicating the high quality of the library. The annotated sequences contribute 12% of the predicted transcriptome size of 20,000. Surprisingly, approximately 37% of the L. stagnalis sequences only have a tBLASTx hit in the EST library of another snail species Aplysia californica (A. californica) even using a low stringency e-value cutoff at 0.01. Using the same cutoff, approximately 67% of the cDNAs have a BLAST hit in the NCBI non-redundant protein and nucleotide sequence databases (nr and nt), suggesting that one third of the sequences may be unique to L. stagnalis. Finally, using the same cutoff (0.01), more than half of the cDNA sequences (54%) do not have a hit in nematode, fruitfly or human genome data, suggesting that the L. stagnalis transcriptome is significantly different from these species as well. The cDNA sequences are enriched in the following gene ontology functional categories: protein binding, hydrolase, transferase, and catalytic enzymes. Conclusion: This study provides novel molecular insights into the transcriptome of an important molluscan model organism. Our findings will contribute to functional analyses in neurobiology, and comparative evolutionary biology. The L. stagnalis CNS EST database is available at http://www.Lymnaea.org/. © 2009 Feng et al; licensee BioMed Central Ltd
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