543 research outputs found
Food and Nutrition Security under Global Trade : A relation-driven agent-based global trade model
Acknowledgements The Scottish Government’s Environment, Agriculture and Food Strategic Research Portfolio and the Belmont Forum/FACCE-JPI (NERC grant number NE/M021327/1) funded this research. We would like to thank two anonymous reviewers for their constructive comments and suggestions, which help us greatly improve the paper.Peer reviewedPublisher PD
Increase of Cr solubility in cubic Sr2FexCr2-xO6-y unit cell using sol-gel assisted synthesis and characterizations of Sr2FeCrO6-y phase
A homogeneous, non-selective chelating system using EDTA–chitosan was created to produce a cubic phase perovskite material Sr2FeCrO6−y.</p
Effects of spines and thorns on Australian arid zone herbivores of different body masses
We investigated the effects of thorns and spines on the feeding of 5 herbivore species in arid Australia. The herbivores were the rabbit ( Oryctolagus cuniculus ), euro kangaroo ( Macropus robustus ), red kangaroo ( Macropus rufus ), sheep ( Ovis aries ), and cattle ( Bos taurus ). Five woody plants without spines or thorns and 6 woody plants with thorns were included in the study. The spines and thorns were not found to affect the herbivores' rates of feeding (items ingested/min), but they did reduce the herbivores' rates of biomass ingestion (g-dry/item). The reduction in biomass ingested occurred in two ways: at a given diameter, twigs with spines and thorns had less mass than undefended plants, and the herbivores consumed twigs with smaller diameters on plants with spines and thorns. The relative importance of the two ways that twigs with spines and thorns provided less biomass varied with herbivore body mass. Reduced twig mass was more important for small herbivores, while large herbivores selected smaller diameters. The effectiveness of spines and thorns as anti-herbivore defenses did not vary with the evolutionary history of the herbivores (i.e. native vs. introduced). Spines and thorns mainly affected the herbivores' selection of maximum twig sizes (reducing diameter and mass), but the minimum twig sizes selected were also reduced.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47795/1/442_2004_Article_BF00317715.pd
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Characterization of subsurface media from locations up- and down-gradient of a uranium-contaminated aquifer.
The processing of sediment to accurately characterize the spatially-resolved depth profiles of geophysical and geochemical properties along with signatures of microbial density and activity remains a challenge especially in complex contaminated areas. This study processed cores from two sediment boreholes from background and contaminated core sediments and surrounding groundwater. Fresh core sediments were compared by depth to capture the changes in sediment structure, sediment minerals, biomass, and pore water geochemistry in terms of major and trace elements including pollutants, cations, anions, and organic acids. Soil porewater samples were matched to groundwater level, flow rate, and preferential flows and compared to homogenized groundwater-only samples from neighboring monitoring wells. Groundwater analysis of nearby wells only revealed high sulfate and nitrate concentrations while the same analysis using sediment pore water samples with depth was able to suggest areas high in sulfate- and nitrate-reducing bacteria based on their decreased concentration and production of reduced by-products that could not be seen in the groundwater samples. Positive correlations among porewater content, total organic carbon, trace metals and clay minerals revealed a more complicated relationship among contaminant, sediment texture, groundwater table, and biomass. The fluctuating capillary interface had high concentrations of Fe and Mn-oxides combined with trace elements including U, Th, Sr, Ba, Cu, and Co. This suggests the mobility of potentially hazardous elements, sediment structure, and biogeochemical factors are all linked together to impact microbial communities, emphasizing that solid interfaces play an important role in determining the abundance of bacteria in the sediments
Interaction of HTLV-1 Tax with minichromosome maintenance proteins accelerates the replication timing program
The Tax oncoprotein encoded by the Human T-cell leukemia virus type 1 (HTLV-1)
plays a pivotal role in viral persistence and pathogenesis. HTLV-1 infected cells proliferate
faster than normal lymphocytes, expand through mitotic division and accumulate genomic
lesions. Here, we show that Tax associates with the minichromosome maintenance MCM2-7
helicase complex and localizes to origins of replication. Tax modulates the spatiotemporal
program of origin activation and fires supplementary origins at the onset of S phase. Thereby,
Tax increases the DNA replication rate, accelerates S phase progression but also generates a
replicative stress characterized by the presence of genomic lesions. Mechanistically, Tax
favors p300 recruitment and histone hyperacetylation at late replication domains advancing
their replication timing in early S phase
Mechanisms of action and antiproliferative properties of Brassica oleracea juice in human breast cancer cell lines
none7noCruciferous vegetables are an important source of compounds that may be useful for chemoprevention.
In this study, we evaluated the antiproliferative activity of juice obtained from leaves of several varieties of
Brassica oleracea on both estrogen receptor (ER)-positive (ER; MCF-7 and BT474) and ER-negative (ER;
MDA-MB-231 and BT20) human breast cancer cell lines. The effect of juice on cell proliferation was evaluated on
DNA synthesis and on cell cycle–related proteins. Juice markedly reduced DNA synthesis, evaluated by [3H]thymidine
incorporation, starting from low concentrations (final concentration 5–15 mL/L), and this activity was
independent of ER. All cauliflower varieties tested suppressed cell proliferation in a dose-dependent manner. Cell
growth inhibition was accompanied by significant cell death at the higher juice concentrations, although no
evidence of apoptosis was found. Interestingly, the juice displayed a preferential activity against breast cancer cells
compared with other mammalian cell lines investigated (ECV304, VERO, Hep2, 3T3, and MCF-10A) (P 0.01). At
the molecular level, the inhibition of proliferation was associated with significantly reduced CDK6 expression and
an increased level of p27 in ER cells but not in ER cells, whereas a common feature in all cell lines was
significantly decreased retinoblastoma protein phosphorylation. These results suggest that the edible part of
Brassica oleracea contains substances that can markedly inhibit the growth of both ER and ER human breast
cancer cells, although through different mechanisms. These results suggest that the widely available cruciferous
vegetables are potential chemopreventive agents. JopenBrandi, Giorgio; Schiavano, GIUDITTA FIORELLA; Zaffaroni, N; De Marco, C; Paiardini, M; Cervasi, B; Magnani, MauroBrandi, G; Schiavano, Gf; Zaffaroni, N; De Marco, C; Paiardini, M; Cervasi, B; Magnani, M
Image-Derived Input Function for Human Brain Using High Resolution PET Imaging with [11C](R)-rolipram and [11C]PBR28
The aim of this study was to test seven previously published image-input methods in state-of-the-art high resolution PET brain images. Images were obtained with a High Resolution Research Tomograph plus a resolution-recovery reconstruction algorithm using two different radioligands with different radiometabolite fractions. Three of the methods required arterial blood samples to scale the image-input, and four were blood-free methods. values was quantified using a scoring system. Using the image input methods that gave the most accurate results with Logan analysis, we also performed kinetic modelling with a two-tissue compartment model.)-rolipram, which has a lower metabolite fraction. Compartment modeling gave less reliable results, especially for the estimation of individual rate constants.C]PBR28), the more difficult it is to obtain a reliable image-derived input function; and 4) in association with image inputs, graphical analyses should be preferred over compartmental modelling
Transcriptome-Wide Assessment of Human Brain and Lymphocyte Senescence
Identifying biological pathways that vary across the age spectrum can provide insight into fundamental mechanisms that impact disease and frailty in the elderly. Few methodological approaches offer the means to explore this question on as broad a scale as gene expression profiling. Here, we have evaluated mRNA expression profiles as a function of age in two populations; one consisting of 191 individuals with ages-at-death ranging from 65-100 years and with post-mortem brain mRNA measurements of 13,216 genes and a second with 1240 individuals ages 15-94 and lymphocyte mRNA estimates for 18,519 genes.Among negatively correlated transcripts, an enrichment of mitochondrial genes was evident in both populations, providing a replication of previous studies indicating this as a common signature of aging. Sample differences were prominent, the most significant being a decrease in expression of genes involved in translation in lymphocytes and an increase in genes involved in transcription in brain, suggesting that apart from energy metabolism other basic cell processes are affected by age but in a tissue-specific manner. In assessing genomic architecture, intron/exon sequence length ratios were larger among negatively regulated genes in both samples, suggesting that a decrease in the expression of non-compact genes may also be a general effect of aging. Variance in gene expression itself has been theorized to change with age due to accumulation of somatic mutations and/or increasingly heterogeneous environmental exposures, but we found no evidence for such a trend here.Results affirm that deteriorating mitochondrial gene expression is a common theme in senescence, but also highlight novel pathways and features of gene architecture that may be important for understanding the molecular consequences of aging
An epigenetic switch induced by Shh signalling regulates gene activation during development and medulloblastoma growth
The Sonic hedgehog (Shh) signalling pathway plays important roles during development and in cancer. Here we report a Shh-induced epigenetic switch that cooperates with Gli to control transcription outcomes. Before induction, poised Shh target genes are marked by a bivalent chromatin domain containing a repressive histone H3K27me3 mark and an active H3K4me3 mark. Shh activation induces a local switch of epigenetic cofactors from the H3K27 methyltransferase polycomb repressive complex 2 (PRC2) to an H3K27me3 demethylase Jmjd3/Kdm6b-centred coactivator complex. We also find that non-enzymatic activities of Jmjd3 are important and that Jmjd3 recruits the Set1/MLL H3K4 methyltransferase complexes in a Shh-dependent manner to resolve the bivalent domain. In vivo, changes of the bivalent domain accompanied Shh-activated cerebellar progenitor proliferation. Overall, our results reveal a regulatory mechanism that underlies the activation of Shh target genes and provides insight into the causes of various diseases and cancers exhibiting altered Shh signalling
Implementing an innovative consent form: the PREDICT experience
<p>Abstract</p> <p>Background</p> <p>In the setting of coronary angiography, generic consent forms permit highly variable communication between patients and physicians. Even with the existence of multiple risk models, clinicians have been unable to readily access them and thus provide patients with vague estimations regarding risks of the procedure.</p> <p>Methods</p> <p>We created a web-based vehicle, PREDICT, for embedding patient-specific estimates of risk from validated multivariable models into individualized consent documents at the point-of-care. Beginning August 2006, outpatients undergoing coronary angiography at the Mid America Heart Institute received individualized consent documents generated by PREDICT. In February 2007 this approach was expanded to all patients undergoing coronary angiography within the four Kansas City hospitals of the Saint Luke's Health System. Qualitative research methods were used to identify the implementation challenges and successes with incorporating PREDICT-enhanced consent documents into routine clinical care from multiple perspectives: administration, information systems, nurses, physicians, and patients.</p> <p>Results</p> <p>Most clinicians found usefulness in the tool (providing clarity and educational value for patients) and satisfaction with the altered processes of care, although a few cardiologists cited delayed patient flow and excessive patient questions. The responses from administration and patients were uniformly positive. The key barrier was related to informatics.</p> <p>Conclusion</p> <p>This preliminary experience suggests that successful change in clinical processes and organizational culture can be accomplished through multidisciplinary collaboration. A randomized trial of PREDICT consent, leveraging the accumulated knowledge from this first experience, is needed to further evaluate its impact on medical decision-making, patient compliance, and clinical outcomes.</p
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