2,988 research outputs found

    Prognostic and Functional Relavance of microRNAs in Acute Myeloid Leukemia

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    Acute myeloid leukemia (AML) is a highly heterogeneous disease, characterized by various cytogenetic and molecular abnormalities. MicroRNAs (miRNAs) are a class of small regulatory RNAs. The prognostic value of miRNAs in AML is yet to be determined. We performed a miRNA expression profiling study in a large cohort of AML patients (n=215) and showed strong association of specific miRNA patterns with different (cyto)genetic AML subtypes. The expression of specific sets of miRNAs are able to predict the different (cyto)genetic subtypes of AML with similar accuracy as with gene expression. In terms of risk stratification we identified miR-212 to be positively associated with favorable survival independent of established confounders in AML (HR=0.77, P=0.015 for overall survival). This finding was confirmed in an independent cohort consisting of 419 AML cases (HR=0.83, P=0.016 for overall survival). High miR-212 expression levels were associated with a gene expression profile which was significantly enriched for genes involved in the immune response. In order to identify miRNAs specifically involved in the pathogenesis of AML, we determined the expression pattern of normal granulocytic subsets. Two miRNAs, miR-9 and miR-9* (miR-9/9*) were found highly aberrantly expressed in AML but low or not expressed in normal cells from healthy individuals. Ectoptic expression of miR-9/9* in a cell line model lead to prohibition of cell differentiation, potentially by down regulation of an important hematopoietic regulation ERG. In summary, distinct miRNA expression patterns reflect the heterogeneity of AML and is able to contribute in classification, predication and might play a role in the leukemogenesis

    The effectiveness of a simple policy for coordinating inventory control and pricing strategies

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    Thesis (S.M.)--Massachusetts Institute of Technology, Computation for Design and Optimization Program, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 51-54).We investigate the effectiveness of an (s, S, p) policy relative to an (s, S, A, p) policy in a single product, periodic review, finite horizon model with stochastic multiplicative demand and fixed ordering cost, in which an (s, S, A, p) policy is optimal. An extensive numerical study shows that empirically an (s, S, p) policy is highly effective relative to an (s, S, A, p) policy. We also formulate two alternative benchmark policies and find that the (s, S, p) policy is superior in terms of profit. In addition, we propose an efficient algorithm with simulated annealing and modified binary search to determine the (s, S, p) policy for the model.by Zhibo Sun.S.M

    Fully localised solitary-wave solutions of the three-dimensional gravity-capillary water-wave problem

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    A model equation derived by B. B. Kadomtsev & V. I. Petviashvili (1970) suggests that the hydrodynamic problem for three-dimensional water waves with strong surface-tension effects admits a fully localised solitary wave which decays to the undisturbed state of the water in every horizontal spatial direction. This prediction is rigorously confirmed for the full water-wave problem in the present paper. The theory is variational in nature. A simple but mathematically unfavourable variational principle for fully localised solitary waves is reduced to a locally equivalent variational principle with significantly better mathematical properties using a generalisation of the Lyapunov-Schmidt reduction procedure. A nontrivial critical point of the reduced functional is detected using the direct methods of the calculus of variations

    Rotation of the pinning direction in the exchange bias training effect in polycrystalline NiFe/FeMn bilayers

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    For polycrystalline NiFe/FeMn bilayers, we have observed and quantified the rotation of the pinning direction in the exchange bias training and recovery effects. During consecutive hysteresis loops, the rotation of the pinning direction strongly depends on the magnetization reversal mechanism of the ferromagnet layer. The interfacial uncompensated magnetic moment of antiferromagnetic grains may be irreversibly switched and rotated when the magnetization reversal process of the ferromagnet layer is accompanied by domain wall motion and domain rotation, respectively

    Information-theoretic attacks in the smart grid

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    Gaussian random attacks that jointly minimize the amount of information obtained by the operator from the grid and the probability of attack detection are presented. The construction of the attack is posed as an optimization problem with a utility function that captures two effects: firstly, minimizing the mutual information between the measurements and the state variables; secondly, minimizing the probability of attack detection via the Kullback-Leibler (KL) divergence between the distribution of the measurements with an attack and the distribution of the measurements without an attack. Additionally, a lower bound on the utility function achieved by the attacks constructed with imperfect knowledge of the second order statistics of the state variables is obtained. The performance of the attack construction using the sample covariance matrix of the state variables is numerically evaluated. The above results are tested in the IEEE 30-Bus test system

    Personality, density and habitat drive the dispersal of invasive crayfish

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    There is increasing evidence that personality traits may drive dispersal patterns of animals, including invasive species. We investigated, using the widespread signal crayfish Pacifastacus leniusculus as a model invasive species, whether effects of personality traits on dispersal were independent of, or affected by, other factors including population density, habitat, crayfish size, sex and limb loss, along an invasion gradient. Behavioural traits (boldness, activity, exploration, willingness to climb) of 310 individually marked signal crayfish were measured at fully-established, newly-established and invasion front sites of two upland streams. After a period at liberty, recaptured crayfish were reassessed for behavioural traits (newly-established, invasion front). Dispersal distance and direction of crayfish movement, local population density, fine-scale habitat characteristics and crayfish size, sex and limb loss were also measured. Individual crayfish exhibited consistency in behavioural traits over time which formed a behavioural syndrome. Dispersal was both positively and negatively affected by personality traits, positively by local population density and negatively by refuge availability. No effect of size, sex and limb loss was recorded. Personality played a role in promoting dispersal but population density and local habitat complexity were also important determinants. Predicting biological invasion in animals is likely to require better integration of these processes

    Stealth attacks on the smart grid

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    Random attacks that jointly minimize the amount of information acquired by the operator about the state of the grid and the probability of attack detection are presented. The attacks minimize the information acquired by the operator by minimizing the mutual information between the observations and the state variables describing the grid. Simultaneously, the attacker aims to minimize the probability of attack detection by minimizing the Kullback-Leibler (KL) divergence between the distribution when the attack is present and the distribution under normal operation. The resulting cost function is the weighted sum of the mutual information and the KL divergence mentioned above. The trade-off between the probability of attack detection and the reduction of mutual information is governed by the weighting parameter on the KL divergence term in the cost function. The probability of attack detection is evaluated as a function of the weighting parameter. A sufficient condition on the weighting parameter is given for achieving an arbitrarily small probability of attack detection. The attack performance is numerically assessed on the IEEE 14-Bus, 30-Bus, and 118-Bus test systems

    Transverse instability of gravity-capillary line solitary water waves

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    The gravity-capillary water-wave problem concerns the irrotational flow of a perfect fluid in a domain bounded below by a rigid bottom and above by a free surface under the influence of gravity and surface tension. In the case of large surface tension the system has a travelling line solitary-wave solution for which the free surface has a localised profile in the direction of propagation and is homogeneous in the transverse direction. In this note we show that this line solitary wave is linearly unstable under spatially inhomogeneous perturbations which are periodic in the direction transverse to propagation

    Phenotypic blood glutathione concentration and selenium supplementation interactions on meat colour stability and fatty acid concentrations in Merino lambs

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    The interaction between blood glutathione (GSH) and supplementation of selenium (Se, 2.5 mg/kg diet) on meat colour and fatty acids concentrations was studied. Forty eight Merino lambs selected for high blood GSH (HGSH) or low GSH (LGSH) concentration were used. They were fed individually with or without Se supplement for 8 weeks. There were interactions (P< 0.05) between GSH and Se on the colour stability (as w630 nm/w580 nm ratio) of m. longissimus (LD), m. semimembranosus (SM) and m. semitendinosus. Without Se supplementation the ratio was higher in HGSH than LGSH group. However, the difference was reduced with Se supplement. Polyunsaturated and n-3 fatty acids in SM and LD were higher in HGSH than in LGSH group (P< 0.05), and did not change with Se supplement. Se supplementation increased Se content in LD (P< 0.001) and the lungs (P< 0.05), but had no influence in the heart

    Effect of substituting guinea grass with soybean hulls on production performance and digestion traits in fattening rabbits

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    [EN] The objective of this study was to evaluate the use of soybean hulls (SH) to substitute guinea grass (GG), traditionally used as fibre source in the diets of fattening rabbits on performance, coefficients of total tract apparent digestibility (CTTAD) of nutrients, gastrointestinal tract development and caecum fermentation. A total of 160 mixed sex Hyla commercial meat rabbits were allocated to 4 experimental groups (40 per treatment) differing in the SH level inclusion in the diet offered to rabbits from 40 to 90 d of age: 0, 50, 100 and 200 g/kg as-fed basis: SH0, SH50, SH100 and SH200 groups, respectively. Growth performance was recorded from 40 to 90 d of age, CTTAD of nutrients from 86 to 90 d of age, and gastrointestinal tract development, caecum fermentation and carcass traits were determined at 90 d of age. Average daily feed intake and the feed/gain ratio were lower in SH100 and SH200 groups than in SH0 group (P0.05). In conclusion, our results suggest that SH can substitute GG in the diets of fattening rabbits up to 200 g/kg in diet with no adverse effects on the growth performance, feed efficiency, carcass traits and meat quality.This study was supported by the earmarked fund for Modern Agro-industry Technology Research System (CARS-44-B-1).Shang, S.; Wu, Z.; Liu, G.; Sun, C.; Ma, M.; Li, FC. (2017). Effect of substituting guinea grass with soybean hulls on production performance and digestion traits in fattening rabbits. World Rabbit Science. 25(3):241-249. https://doi.org/10.4995/wrs.2017.6654SWORD24124925
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