177 research outputs found
Maintenance of heat and water balances as a scale-up criterion for the production of ethanol by Schwanniomyces castellii in a solid state fermentation system
The scale-up of column fermenters by 6 to 410 gravimetric scale factors, from 10 g moist substrate size, has been achieved efficiently by maintaining heat and water balances in the media. The data on the patterns of ethanol production, biomass formation, the concentration of different carbohydrates, dry matter and pH values against time were of equal magnitude in 10- and 60-g size column fermenters. The reactors of 60-, 370- and 4100-g sizes also compared well in respect of O2 consumption, CO2 evolution and the specific growth rates in aerobic and anaerobic fermentations phases. The overall productivities of ethanol were similar in all the four column fermenters. The ability to obtain the same results in all the fermenter sizes, in spite of the increases in the diameter and the height of the columns, indicates the high potential of this simple scale-up criterion which has not been used earlier for scale-up of any fermentation process. (Résumé d'auteur
The Scarlet Letter: A critical review
Nathaniel Hawthornâs 19th century romance The Scarlet Letter centres on the simple transgression of adultery and its social consequences. Hawthornâs narrative and story-telling skill, however, is far from simple; the author manages to subtly and cleverly set the tale within a framework of other transgressions. Ideas of space and other social constructions such including language and belief systems are tested and subverted in this description of a 17th century Puritan settlement. In this paper David Littlefield and Rachel Sara set out the transgressive qualities of this classic American text, putting it into the context of the theme Body + Space and demonstrating how the book pre-figures much 20th century thinking on the subject
Enhancement of the magnetic anisotropy of nanometer-sized Co clusters: influence of the surface and of the inter-particle interactions
We study the magnetic properties of spherical Co clusters with diameters
between 0.8 nm and 5.4 nm (25 to 7500$ atoms) prepared by sequential sputtering
of Co and Al2O3. The particle size distribution has been determined from the
equilibrium susceptibility and magnetization data and it is compared to
previous structural characterizations. The distribution of activation energies
was independently obtained from a scaling plot of the ac susceptibility.
Combining these two distributions we have accurately determined the effective
anisotropy constant Keff. We find that Keff is enhanced with respect to the
bulk value and that it is dominated by a strong anisotropy induced at the
surface of the clusters. Interactions between the magnetic moments of adjacent
layers are shown to increase the effective activation energy barrier for the
reversal of the magnetic moments. Finally, this reversal is shown to proceed
classically down to the lowest temperature investigated (1.8 K).Comment: 13 figures submitted to Phys. Rev.
ĐŃĐžĐœŃОпО ŃĐżŃĐ°ĐČĐ»ŃĐœĐœŃ ĐżĐ”ŃŃĐŸĐœĐ°Đ»ĐŸĐŒ ŃŃĐ»ŃŃŃĐșĐŸĐłĐŸŃĐżĐŸĐŽĐ°ŃŃŃĐșĐžŃ ĐżŃĐŽĐżŃĐžŃĐŒŃŃĐČ (ĐœĐ° ĐżŃĐžĐșĐ»Đ°ĐŽŃ ĐŃĐłĐ°ĐœŃŃĐșĐŸŃ ĐŸĐ±Đ»Đ°ŃŃŃ)
ĐŁ ŃŃĐ°ŃŃŃ ĐżŃĐŸĐ°ĐœĐ°Đ»ŃĐ·ĐŸĐČĐ°ĐœĐŸ ŃŃŃĐ°ŃĐœĐžĐč ŃŃĐ°Đœ ŃŃĐ»ŃŃŃĐșĐŸĐłĐŸŃĐżĐŸĐŽĐ°ŃŃŃĐșĐŸĐłĐŸ ĐČĐžŃĐŸĐ±ĐœĐžŃŃĐČĐ° ĐČ ĐŃĐłĐ°ĐœŃŃĐșŃĐč
ĐŸĐ±Đ»Đ°ŃŃŃ ŃĐ° Đ·ĐŽŃĐčŃĐœĐ”ĐœĐ° ĐŸŃŃĐœĐșĐ° пДŃŃпДĐșŃĐžĐČ ŃĐ”ŃĐŸŃĐŒŃĐČĐ°ĐœĐœŃ ŃĐżŃĐ°ĐČĐ»ŃĐœĐœŃ ĐżĐ”ŃŃĐŸĐœĐ°Đ»ĐŸĐŒ ĐœĐ° ĐżŃĐŽĐżŃĐžŃĐŒŃŃĐČĐ°Ń
ĐĐĐ. РДгŃĐ”ŃŃĐčĐœĐžĐŒ Đ°ĐœĐ°Đ»ŃĐ·ĐŸĐŒ ĐŸŃŃĐœĐ”ĐœĐŸ ŃŃŃĐżŃĐœŃ ĐČплОĐČŃ ĐŽĐ”ŃĐșĐžŃ
ŃĐ°ĐșŃĐŸŃŃĐČ ĐœĐ° ŃĐ”ĐœŃабДлŃĐœŃŃŃŃ ĐżĐ”ŃŃĐŸĐœĐ°Đ»Ń. Đ Đ”ĐșĐŸĐŒĐ”ĐœĐŽŃŃŃŃŃŃ ĐČĐžĐșĐŸŃĐžŃŃĐ°ĐœĐœŃ SWOT-Đ°ĐœĐ°Đ»ŃĐ·Ń ĐŽĐ»Ń ĐŽĐŸŃĐ»ŃĐŽĐ¶Đ”ĐœĐœŃ Đč ŃĐŸŃĐŒŃĐČĐ°ĐœĐœŃ ŃĐ°ŃŃĐŸĐœĐ°Đ»ŃĐœĐŸĐłĐŸ ŃĐżŃĐ°ĐČĐ»ŃĐœĐœŃ ĐżĐ”ŃŃĐŸĐœĐ°Đ»ĐŸĐŒ ĐżŃĐŽĐżŃĐžŃĐŒŃŃĐČ ĐĐĐ.Performed analysis of the current state of agriculture in the Luhansk region, evaluated the prospects for personnel
resources reforming for the agricultural enterprises. The degree of factors influencing on profitability of personnel is
appraised by the regressive analysis. SWOT-analysis is recommended for research and forming of agrarian enterprises
rational management of a personnel
Setting clinical performance specifications to develop and evaluate biomarkers for clinical use
Background: Biomarker discovery studies often claim âpromisingâ findings, motivating further studies and marketing as medical tests. Unfortunately, the patient benefits promised are often inadequately explained to guide further evaluation, and few biomarkers have translated to improved patient care. We present a practical guide for setting minimum clinical performance specifications to strengthen clinical performance study design and interpretation.
Methods: We developed a step-by-step approach using test evaluation and decision-analytic frameworks and present with illustrative examples.
Results: We define clinical performance specifications as a set of criteria that quantify the clinical performance a new test must attain to allow better health outcomes than current practice. We classify the proposed patient benefits of a new test into three broad groups and describe how to set minimum clinical performance at the level where the potential harm of false-positive and false-negative results does not outweigh the benefits. (1) For add-on tests proposed to improve disease outcomes by improving detection, define an acceptable trade-off for false-positive versus true-positive results; (2) for triage tests proposed to reduce unnecessary tests and treatment by ruling out disease, define an acceptable risk of false-negatives as a safety threshold; (3) for replacement tests proposed to provide other benefits, or reduce costs, without compromising accuracy, use existing tests to benchmark minimum accuracy levels.
Conclusions: Researchers can follow these guidelines to focus their study objectives and to define statistical hypotheses and sample size requirements. This way, clinical performance studies will allow conclusions about whether test performance is sufficient for intended use
Canonical Wnt signaling negatively modulates regulatory T cell function
Foxp3 is crucial for both the development and function of regulatory T (Treg) cells; however, the posttranslational mechanisms regulating Foxp3 transcriptional output remain poorly defined. Here, we demonstrate that Tcell factor 1 (TCF1) and Foxp3 associates in Treg cells and that active Wnt signaling disrupts Foxp3 transcriptional activity. A global chromatin immunoprecipitation sequencing comparison in Treg cells revealed considerable overlap between Foxp3 and Wnt target genes. The activation of Wnt signaling reduced Treg-mediated suppression both invitro and invivo, whereas disruption of Wnt signaling in Treg cells enhanced their suppressive capacity. The activation of effector Tcells increased Wnt3a production, and Wnt3a levels were found to be greatly increased in mononuclear cells isolated from synovial fluid versus peripheral blood of arthritis patients. We propose a model in which Wnt produced under inflammatory conditions represses Treg cell function, allowing a productive immune response, but, if uncontrolled, could lead to the development of autoimmunity
Antiâinflammatory and acetylcholinesterase activity of extract, fractions and five compounds isolated from the leaves and twigs of Artemisia annua growing in Cameroon
BACKGROUND : Natural products, including those derived from higher plants have, over the years, contributed greatly
to the development of modern therapeutic drugs. Due to the medicinal importance in traditional practice and the
diversified biology and chemistry of the constituents from Artemisia spp., the genus has been receiving growing
attention. The aim of this study was to investigate the ability of the ethanol extract, four fractions (F1âF4) and five
compounds namely artemisinin (1), scopoletin (2), chrysosplenetin (3), eupatin (4) and 3-O-ÎČ-d-glucopyranoside of
sitosterol (5) isolated from A. annua to modulate the activity of anticholinesterase (AchE) and the production of nitric
oxide (NO) in LPS-activated RAW 264.7 macrophages.
RESULTS : At the lowest concentration tested (6.25 ÎŒg/mL), the crude extract and fraction F2 had the highest NO
inhibitory activity (72.39 and 71.00 % inhibition respectively) without significant toxicity on the viability of macrophage
cells (93.86 and 79.87 % of cell viability respectively). The crude extract inhibited AchE activity by 71.83 % (at
1 mg/mL) with an IC50 value of 87.43 ÎŒg/mL while F2 and F4 were the most active fractions (IC50 values of 36.75 and
28.82 ÎŒg/mL). Artemisinin (1) and chrysosplenetin (3) had the highest AChE activity with 71.67 and 80.00 % inhibition
(at 0.1 mg/mL) and IC50 values of 29.34 and 27.14 ÎŒg/mL, respectively.
CONCLUSION : Our results validate the traditional use of A. annua and could help to support the usefulness of this plant
in the treatment of inflammatory and neurological disorders especially where nitric oxide and a cholinesterase are
involved.The
National Research Foundation (NRF) and Medical Research Council (MRC)
provided funding to support this study. The Université des Montagnes provided
financial support to phytochemical experimental part of this work.http://www.springerplus.comam2016Paraclinical Science
IGF1R signaling drives antiestrogen resistance through PAK2/PIX activation in luminal breast cancer
Antiestrogen resistance in estrogen receptor positive (ER+) breast cancer is associated with increased expression and activity of insulin-like growth factor 1 receptor (IGF1R). Here, a kinome siRNA screen has identified 10 regulators of IGF1R-mediated antiestrogen with clinical significance. These include the tamoxifen resistance suppressors BMPR1B, CDK10, CDK5, EIF2AK1, and MAP2K5, and the tamoxifen resistance inducers CHEK1, PAK2, RPS6KC1, TTK, and TXK. The p21-activated kinase 2, PAK2, is the strongest resistance inducer. Silencing of the tamoxifen resistance inducing genes, particularly PAK2, attenuates IGF1R-mediated resistance to tamoxifen and fulvestrant. High expression of PAK2 in ER+ metastatic breast cancer patients is correlated with unfavorable outcome after first-line tamoxifen monotherapy. Phospho-proteomics has defined PAK2 and the PAK-interacting exchange factors PIXα/ÎČ as downstream targets of IGF1R signaling, which are independent from PI3K/ATK and MAPK/ERK pathways. PAK2 and PIXα/ÎČ modulate IGF1R signaling-driven cell scattering. Targeting PIXα/ÎČ entirely mimics the effect of PAK2 silencing on antiestrogen re-sensitization. These data indicate PAK2/PIX as an effector pathway in IGF1R-mediated antiestrogen resistance
Measurement of the branching fraction
The branching fraction is measured in a data sample
corresponding to 0.41 of integrated luminosity collected with the LHCb
detector at the LHC. This channel is sensitive to the penguin contributions
affecting the sin2 measurement from The
time-integrated branching fraction is measured to be . This is the most precise measurement to
date
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