1,302 research outputs found
Qunatification of Metabolites in MR Spectroscopic Imaging using Machine Learning
Magnetic Resonance Spectroscopic Imaging (MRSI) is a clinical imaging
modality for measuring tissue metabolite levels in-vivo. An accurate estimation
of spectral parameters allows for better assessment of spectral quality and
metabolite concentration levels. The current gold standard quantification
method is the LCModel - a commercial fitting tool. However, this fails for
spectra having poor signal-to-noise ratio (SNR) or a large number of artifacts.
This paper introduces a framework based on random forest regression for
accurate estimation of the output parameters of a model based analysis of MR
spectroscopy data. The goal of our proposed framework is to learn the spectral
features from a training set comprising of different variations of both
simulated and in-vivo brain spectra and then use this learning for the
subsequent metabolite quantification. Experiments involve training and testing
on simulated and in-vivo human brain spectra. We estimate parameters such as
concentration of metabolites and compare our results with that from the
LCModel
Subtle changes in the flavour and texture of a drink enhance expectations of satiety
Background: The consumption of liquid calories has been implicated in the development of obesity and weight gain. Energy-containing drinks are often reported to have a weak satiety value: one explanation for this is that because of their fluid texture they are not expected to have much nutritional value. It is important to consider what features of these drinks can be manipulated to enhance their expected satiety value. Two studies investigated the perception of subtle changes in a drink’s viscosity, and the extent to which thick texture and creamy flavour contribute to the generation of satiety expectations. Participants in the first study rated the sensory characteristics of 16 fruit yogurt drinks of increasing viscosity. In study two, a new set of participants evaluated eight versions of the fruit yogurt drink, which varied in thick texture, creamy flavour and energy content, for sensory and hedonic characteristics and satiety expectations.
Results: In study one, participants were able to perceive small changes in drink viscosity that were strongly related to the actual viscosity of the drinks. In study two, the thick versions of the drink were expected to be more filling and have a greater expected satiety value, independent of the drink’s actual energy content. A creamy flavour enhanced the extent to which the drink was expected to be filling, but did not affect its expected satiety.
Conclusions: These results indicate that subtle manipulations of texture and creamy flavour can increase expectations that a fruit yogurt drink will be filling and suppress hunger, irrespective of the drink’s energy content. A thicker texture enhanced expectations of satiety to a greater extent than a creamier flavour, and may be one way to improve the anticipated satiating value of energy-containing beverages
Evidence for a role of TRIB3 in the regulation of megakaryocytopoiesis
Megakaryocytopoiesis is a complex differentiation process driven by the hormone
thrombopoietin by which haematopoietic progenitor cells give rise to
megakaryocytes, the giant bone marrow cells that in turn break down to form blood
platelets. The Tribbles Pseudokinase 3 gene (TRIB3) encodes a pleiotropic protein
increasingly implicated in the regulation of cellular differentiation programmes.
Previous studies have hinted that TRIB3 could be also involved in
megakaryocytopoiesis but its role in this process has so far not been investigated.
Using cellular model systems of haematopoietic lineage differentiation here we
demonstrate that TRIB3 is a negative modulator of megakaryocytopoiesis. We found
that in primary cultures derived from human haematopoietic progenitor cells,
thrombopoietin-induced megakaryocytic differentiation led to a time and dosedependent
decrease in TRIB3 mRNA levels. In the haematopoietic cell line UT7/mpl,
silencing of TRIB3 increased basal and thrombopoietin-stimulated megakaryocyte
antigen expression, as well as basal levels of ERK1/2 phosphorylation. In primary
haematopoietic cell cultures, silencing of TRIB3 facilitated megakaryocyte
differentiation. In contrast, over-expression of TRIB3 in these cells inhibited the
differentiation process. The in-vitro identification of TRIB3 as a negative regulator of
megakaryocytopoiesis suggests that in-vivo this gene could be important for the
regulation of platelet production
Adenoviral vector-mediated expression of a gene encoding secreted, EpCAM-targeted carboxylesterase-2 sensitises colon cancer spheroids to CPT-11
CPT-11 (irinotecan or 7-ethyl-10[4-(1-piperidino)-1-piperidino] carbonyloxycamptothecin) is an anticancer agent in use for the treatment of colon cancer. In order to be fully active, CPT-11 needs to be converted into SN-38 (7-ethyl-10-hydroxycamptothecin) by the enzyme carboxylesterase (CE). In humans, only a minority of CPT-11 is converted to SN-38. To increase the antitumour effect of CPT-11 by gene-directed enzyme prodrug therapy, we constructed a replication-deficient adenoviral vector Ad.C28-sCE2 containing a fusion gene encoding a secreted form of human liver CE2 targeted to the surface antigen epithelial cell adhesion molecule (EpCAM) that is highly expressed on most colon carcinoma cells. By targeting CE2 to EpCAM, the enzyme should accumulate specifically in tumours and leakage into the circulation should be minimised. Ad.C28-sCE2-transduced colon carcinoma cells expressed and secreted active CE that bound specifically to EpCAM-expressing cells. In sections of three-dimensional colon carcinoma spheroids transduced with Ad.C28-sCE2, it was shown that C28-sCE2 was capable of binding untransduced cells. Most importantly, treatment of these spheroids with nontoxic concentrations of CPT-11 resulted in growth inhibition comparable to treatment with SN-38. Therefore, Ad.C28-sCE2 holds promise in gene therapy approaches for the treatment of colon carcinoma
Выявление понятий и их взаимосвязей в рамках технологии контент-мониторинга
Приведены подходы к решению проблемы выявления фактографической информации из неструктурированных текстовых потоков. Описаны технологические решения, позволяющие извлекать из полнотекстовых документов такие понятия как фирмы, фамилии, географические названия и т.п., а также выявлять силу их взаимосвязей на основе применения двух алгоритмов. Первый из этих алгоритмов основывается на учете совместного вхождения понятий в одни и те же документы, а второй на учете общего для рассматриваемых понятий контекста.Наведено підходи до вирішення проблеми виявлення фактографічної інформації з неструктурованих текстових потоків. Описано технологічні рішення, що дозволяють добути з повнотекстових документів такі поняття як фірми, прізвища, географічні назви тощо, а також виявляти силу їхніх взаємозв’язків на базі застосування двох алгоритмів. Перший з цих алгоритмів базується на врахуванні спільного входження понять до одних і тих самих документів, а другий — на врахуванні загального для понять, що розглядаються, контексту.Approaches to the solution of a problem of revealing factual information from unstructured text flows are given. The technological solutions, allowing to take from text-through documents such concepts as a firm, a surname, place names, etc., and also to reveal force of their interrelations on the basis of application of two algorithms are described. The first of these algorithms is based on the account of joint concepts occurrence in the same documents, and the second one on the account of the context common for considered concepts
Is the prevalence of psychiatric disorders associated with urbanization?
Objectives In many countries, the total rate of psychiatric disorders tends to be higher in urban areas than in rural areas. The relevance of this phenomenon is that it may help in identifying environmental factors that are important in the pathogenesis of mental disorders. Moreover, urban preponderance suggests that the allocation of funds and services should take urbanization levels into account. Method The Netherlands Mental Health Survey and Incidence Study (NEMESIS) used the Composite International Diagnostic Interview (CIDI) to determine the prevalence of DSM-III-R disorders in a sample of 7,076 people aged 18–64. The sample was representative of the population as a whole. The study population was assigned to five urbanization categories defined at the level of municipalities. The association between urbanization and 12-month prevalence rates of psychiatric disorders was studied using logistic regression taking several confounders into account. Results The prevalence of psychiatric disorders gradually increased over five levels of urbanization. This pattern remained after adjustment for a range of confounders. Comorbidity rates also increased with level of urbanization. Conclusion This study confirms that psychiatric disorders are more common and more complex in more urbanized areas. This should be reflected in service allocation and may help in identifying environmental factors of importance for the aetiology of mental disorders. j Key words population survey – psychiatric epidemiology – mental disorders – urbanizatio
Molecular characterisation of protist parasites in human-habituated mountain gorillas (Gorilla beringei beringei), humans and livestock, from Bwindi impenetrable National Park, Uganda
Over 60 % of human emerging infectious diseases are zoonotic, and there is growing evidence of the zooanthroponotic transmission of diseases from humans to livestock and wildlife species, with major implications for public health, economics, and conservation. Zooanthroponoses are of relevance to critically endangered species; amongst these is the mountain gorilla (Gorilla beringei beringei) of Uganda. Here, we assess the occurrence of Cryptosporidium, Cyclospora, Giardia, and Entamoeba infecting mountain gorillas in the Bwindi Impenetrable National Park (BINP), Uganda, using molecular methods. We also assess the occurrence of these parasites in humans and livestock species living in overlapping/adjacent geographical regions
Lipase-catalysed acylation of starch and determination of the degree of substitution by methanolysis and GC
Background: Natural polysaccharides such as starch are becoming increasingly interesting as renewable starting materials for the synthesis of biodegradable polymers using chemical or enzymatic methods. Given the complexity of polysaccharides, the analysis of reaction products is challenging. Results: Esterification of starch with fatty acids has traditionally been monitored by saponification and back-titration, but in our experience this method is unreliable. Here we report a novel GC-based method for the fast and reliable quantitative determination of esterification. The method was used to monitor the enzymatic esterification of different starches with decanoic acid, using lipase from Thermomyces lanuginosus. The reaction showed a pronounced optimal water content of 1.25 mL per g starch, where a degree of substitution (DS) of 0.018 was obtained. Incomplete gelatinization probably accounts for lower conversion with less water. Conclusions: Lipase-catalysed esterification of starch is feasible in aqueous gel systems, but attention to analytical methods is important to obtain correct DS values
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