4,006 research outputs found

    Radio Planetary Nebulae in the Large Magellanic Cloud

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    We present 21 new radio-continuum detections at catalogued planetary nebula (PN) positions in the Large Magellanic Cloud (LMC) using all presently available data from the Australia Telescope Online Archive at 3, 6, 13 and 20 cm. Additionally, 11 previously detected LMC radio PNe are re-examined with 7 7 detections confirmed and reported here. An additional three PNe from our previous surveys are also studied. The last of the 11 previous detections is now classified as a compact \HII\ region which makes for a total sample of 31 radio PNe in the LMC. The radio-surface brightness to diameter (Σ\Sigma-D) relation is parametrised as ΣDβ\Sigma \propto {D^{ - \beta }}. With the available 6~cm Σ\Sigma-DD data we construct Σ\Sigma-DD samples from 28 LMC PNe and 9 Small Magellanic Cloud (SMC) radio detected PNe. The results of our sampled PNe in the Magellanic Clouds (MCs) are comparable to previous measurements of the Galactic PNe. We obtain β=2.9±0.4\beta=2.9\pm0.4 for the MC PNe compared to β=3.1±0.4\beta = 3.1\pm0.4 for the Galaxy. For a better insight into sample completeness and evolutionary features we reconstruct the Σ\Sigma-DD data probability density function (PDF). The PDF analysis implies that PNe are not likely to follow linear evolutionary paths. To estimate the significance of sensitivity selection effects we perform a Monte Carlo sensitivity simulation on the Σ\Sigma-DD data. The results suggest that selection effects are significant for values larger than β2.6\beta \sim 2.6 and that a measured slope of β=2.9\beta=2.9 should correspond to a sensitivity-free value of 3.4\sim 3.4.Comment: 19 pages, 9 figures, 6 table

    Integrated economic modeling of global and regional micronutrient security:

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    In this paper, we examine the implications of alternative country-specific scenarios for biofortification on the reduction of micronutrient deficiency prevalence in under-fives. The scenarios are implemented within a long-term projections model of agriculture production and consumption, given the timeframe needed to develop and implement biofortification of crops and the need to account for changing diets over time. The effectiveness of the various biofortification strategies is largely determined by the evolution of regional dietary patterns over time, which show continued reliance on staple food crops among the poor. It suggests that cereal grain-focused biofortification is likely to be most effective in South Asia, while targeting roots and tubers is most effective in Sub-Saharan Africa.Biofortification, Micronutrients, Economic models,

    Optical Biopsy Method for Breast Cancer Diagnosis Based on Artificial Neural Network Classification of Fluorescence Landscape Data

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    Supervised self-organizing map, a type of artificial neural network, is applied for classification of human breast tissue samples utilizing data obtained from fluorescence landscape measurements. Female breast tissue samples were taken soon after the surgical resection, identified and stored at -80 degrees C until fluorescence measurements. From fluorescence landscapes obtained in UV-VIS region spectral features showing statistically significant differences between malignant and normal samples are identified and further quantified to serve as a training input to neural network. Additional set of samples was used as a test group input to trained network in order to evaluate performance of proposed optical biopsy method. Classification sensitivity of 83.9% and specificity of 88.9% are found

    Trisubstituted pyrazolopyrimidines as novel angiogenesis inhibitors.

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    Current inhibitors of angiogenesis comprise either therapeutic antibodies (e.g. bevacicumab binding to VEGF-A) or small molecular inhibitors of receptor tyrosin kinases like e.g. sunitinib, which inhibits PDGFR and VEGFR. We have recently identified cyclin-dependent kinase 5 (Cdk5) as novel alternative and pharmacologically accessible target in the context of angiogenesis. In the present work we demonstrate that trisubstituted pyrazolo[4,3-d]pyrimidines constitute a novel class of compounds which potently inhibit angiogenesis. All seven tested compounds inhibited endothelial cell proliferation with IC(50) values between 1 and 18 µM. Interestingly, this seems not to be due to cytotoxicity, since none of them showed acute cytotoxic effects on endothelial cells at a concentration of 10 µM,. The three most potent compounds (LGR1404, LGR1406 and LGR1407) also inhibited cell migration (by 27, 51 and 31%, resp.), chemotaxis (by 50, 70 and 60% in accumulative distance, resp.), and tube formation (by 25, 60 and 30% of total tube length, resp.) at the non-toxic concentration of 10 µM. Furthermore, angiogenesis was reduced in vivo in the CAM assay by these three compounds. A kinase selectivity profiling revealed that the compounds prevalently inhibit Cdk2, Cdk5 and Cdk9. The phenotype of the migrating cells (reduced formation of lamellipodia, loss of Rac-1 translocation to the membrane) resembles the previously described effects of silencing of Cdk5 in endothelial cells. We conclude that especially LGR1406 and LGR1407 are highly attractive anti-angiogenic compounds, whose effects seem to largely depend on their Cdk5 inhibiting properties

    Redox-sensitive transcription factor NFkB in brain of stressed wistar rats

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    Neuroendocrine stress (NES) causes stress-hormones increase and alters balance of intracellular reactive oxygen species (ROS) leading to vulnerability of brain neurons. Prolonged alterations of cell redox milieux may also lead to altered expression of redox sensitive transcription factors, such as NFκB, resposible for brain cell protection. In the presented study NFκB p65 (NFκB) levels were determined in hippocampus and brain cortex of Wistar male rats.exposed to stress of different duration The cytosolic NFκB level was unchanged in acute stress (A, 2h), but significantly down-regulated in either chronic (C,21-day) or combined (C+A) stress. The depletion of NFκB from cell cytosol probably reflected its nuclear translocation and decoupling from the repressive action of glucocorticoid receptor. Through initially protective, NFkB overactivity may lead to accumulation of toxic H2O2 and compromise brain cell capacity to restore homeostasis.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

    Current efficiency in the chlorate cell process

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    A mathematical model has been set up for current efficiency in a chlorate cell acting as an ideal electrochemical tubular reactor with a linear increase in hypochlorite concentration from the entrance to the exit. Good agreement was found between the results on current efficiency experimentally obtained under simulated industrial chlorate production conditions and the theoretical values provided by the mathematical model. © 2014 SCS. All rights reserved

    Corticosterone level alters optimal heat shock protein 90/glucocorticoid receptor ratio in hippocampus of stressed rats

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    Hippocampus (HIPPO) is one of the key brain structures, rich in glucocorticoid receptor (GR), a transcriptional factor involved in negative feedback of hypothalamic- pituitary-adrenal (HPA) axis in response to stress. Heat shock proteins accompany GR maintaining its optimal conformation, ligand binding ability and translocation to the nucleus. In order to evaluate the expression of GR, Hsp90 and their ratio we exploited three diverse types of stress (acute immobilization, chronic isolation and combination of the two). Our results indicated the same pattern of expression and compartmental distribution for both proteins, as well as for their ratio, under acute and combined stress when the level of corticosterone (CORT) was high. On the contrary, when CORT was low, such as in chronic stress, Hsp90/GR ratio exhibited opposite pattern of expression and GR was not translocated to the nucleus.Physical chemistry 2008 : 9th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 200

    N-(2,5-Dichloro­phen­yl)maleamic acid

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    The asymmetric unit of the title compound, C10H7Cl2NO3, contains two independent mol­ecules. The mol­ecular conformation of each maleamic unit is stabilized by an intra­molecular O—H⋯Ocarbon­yl hydrogen bond owing to the anti disposition of the participating entities. The mean planes through the benzene ring and the amido group are inclined at angles of 45.7 (1) and 40.8 (1)° in the two mol­ecules. In the crystal, the independent mol­ecules self-associate via N—H⋯O hydrogen bonds into zigzag ribbons propagating along the a axis. The ribbons are weakly coupled by C—H⋯π and C—H⋯O inter­actions
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