999 resultados para Stochastic identification
Resumo:
The recently discovered apolipoprotein AV (apoAV) gene has been reported to be a key player in modulating plasma triglyceride levels. Here we identify the hepatocyte nuclear factor-4 (HNF-4 ) as a novel regulator of human apoAV gene. Inhibition of HNF-4 expression by small interfering RNA resulted in down-regulation of apoAV. Deletion, mutagenesis, and binding assays revealed that HNF-4 directly regulates human apoAV promoter through DR1 [a direct repeat separated by one nucleotide (nt)], and via a novel element for HNF-4 consisting of an inverted repeat separated by 8 nt (IR8). In addition, we show that the coactivator peroxisome proliferator-activated receptor- coactivator-1 was capable of stimulating the HNF-4 -dependent transactivation of apoAV promoter. Furthermore, analyses in human hepatic cells demonstrated that AMP-activated protein kinase (AMPK) and the MAPK signaling pathway regulate human apoAV expression and suggested that this regulation may be mediated, at least in part, by changes in HNF-4 . Intriguingly, EMSAs and mice with a liver-specific disruption of the HNF-4 gene revealed a species-distinct regulation of apoAV by HNF-4 , which resembles that of a subset of HNF-4 target genes. Taken together, our data provide new insights into the binding properties and the modulation of HNF-4 and underscore the role of HNF-4 in regulating triglyceride metabolism.
Resumo:
Tutkimuksen tarkoituksena oli tunnistaa nykyiset sekä potentiaaliset avainasiakkaat case yritykselle. Avainasiakkaat tunnistettiin Chevertonin tunnistamis- ja valintamatriisin avulla, jossa asiakkaan sijoittumista matriisiin arvioidaan asiakkaan houkuttelevuuden sekä toimittajan suhteellisten vahvuuksien avulla. Kriteereiksi avainasiakkaiden tunnistamiseen valittiin asiakkaan vuotuinen ostovolyymi, asiakkaan business-potentiaali sekä case-yrityksen toimittajaosuus. Asiakkaat luokiteltiin avainasiakkaisiin, kehitettäviin avainasiakkaisiin, ylläpidettäviin asiakkaisiin sekä satunnaisiin asiakkaisiin. Tutkimus tarjosi lähtökohdan case-yrityksen uusille avainasiakaspäälliköille sekä osoitti suunnan tulevaisuuden tutkimustarpeille. Aktiivisen tiedonvaihdannan kautta eri myyntikonttoreiden johtohenkilöstön sekä myös yrityksen eri funktionaalisten divisioonien välillä voidaan saavuttaa kilpailuetua kun lähestytään asiakasta toimintojaan järkiperäisesti koordinoineena toimittajana samalla kun asiakkaat keskittävät ostojaan. Jotta yrityksen tavoitteet, markkinamahdollisuudet sekä resurssit olisivat hyvin tasapainossa, tulisi myös asiakaskannattavuutta sekä asiakkaiden strategista merkittävyyttä arvioida ja mitata säännöllisesti tässä tutkimuksessa käytettyjen tunnistuskriteereiden lisäksi.
Resumo:
"This paper will discuss the major developments in the area of fingerprint" "identification that followed the publication of the National Research Council (NRC, of the US National Academies of Sciences) report in 2009 entitled: Strengthening Forensic Science in the United States: A Path Forward. The report portrayed an image of a field of expertise used for decades without the necessary scientific research-based underpinning. The advances since the report and the needs in selected areas of fingerprinting will be detailed. It includes the measurement of the accuracy, reliability, repeatability and reproducibility of the conclusions offered by fingerprint experts. The paper will also pay attention to the development of statistical models allow- ing assessment of fingerprint comparisons. As a corollary of these developments, the next challenge is to reconcile a traditional practice domi- nated by deterministic conclusions with the probabilistic logic of any statistical model. There is a call for greater candour and fingerprint experts will need to communicate differently on the strengths and limitations of their findings. Their testimony will have to go beyond the blunt assertion" "of the uniqueness of fingerprints or the opinion delivered ispe dixit."
Resumo:
BACKGROUND: Known antiretroviral restriction factors are encoded by genes that are under positive selection pressure, induced during HIV-1 infection, up-regulated by interferons, and/or interact with viral proteins. To identify potential novel restriction factors, we performed genome-wide scans for human genes sharing molecular and evolutionary signatures of known restriction factors and tested the anti-HIV-1 activity of the most promising candidates. RESULTS: Our analyses identified 30 human genes that share characteristics of known restriction factors. Functional analyses of 27 of these candidates showed that over-expression of a strikingly high proportion of them significantly inhibited HIV-1 without causing cytotoxic effects. Five factors (APOL1, APOL6, CD164, TNFRSF10A, TNFRSF10D) suppressed infectious HIV-1 production in transfected 293T cells by >90% and six additional candidates (FCGR3A, CD3E, OAS1, GBP5, SPN, IFI16) achieved this when the virus was lacking intact accessory vpr, vpu and nef genes. Unexpectedly, over-expression of two factors (IL1A, SP110) significantly increased infectious HIV-1 production. Mechanistic studies suggest that the newly identified potential restriction factors act at different steps of the viral replication cycle, including proviral transcription and production of viral proteins. Finally, we confirmed that mRNA expression of most of these candidate restriction factors in primary CD4+ T cells is significantly increased by type I interferons. CONCLUSIONS: A limited number of human genes share multiple characteristics of genes encoding for known restriction factors. Most of them display anti-retroviral activity in transient transfection assays and are expressed in primary CD4+ T cells.
Resumo:
Työn tavoitteena on tunnistaa toiminnallisia riskitekijöitä rahoituspalveluita tarjoavan yrityksen IT-organisaatiossa sekä löytää arkipäiväisiä keinoja hallita näitä riskejä. Työssä riskejä on myös tarkasteltu mahdollisen ulkoistuksen yhteydessä. Fuusiot ovat yleisiä rahoitusalan yrityksissä. Yhteenliittymien tuloksena yritysten IT-arkkitehtuuri voi olla monimutkainen ja kulttuurierot yrityksessä suuria. Synergia- ja mittakaavaetuja saadakseen yritys keskittää toimintojaan ja IT-ratkaisujaan. Riskien tunnistaminen on riskienhallintaprosessin tärkein vaihe. Tässä tutkimuksessa riskit ja riskitekijät tunnistettiin itsearvioinnin avulla kysymyssarjoja hyväksikäyttäen. Monet riskitekijät liittyivät sisäisen valvonnan ja seurannan puutteisiin. Myöhemmin näille riskeille pohdittiin työryhmässä käytännönläheisiä hallintakeinoja. Yritys voi siirtää tai jakaa IT -riskejä ulkoistamalla. Ulkoistaminen voi kuitenkin tuoda mukaan myös uusia riskitekijöitä. Ennen ulkoistamispäätöstä yrityksen sisäisten prosessien ja organisaation on oltava järjestyksessä, jotta sopimuksen kannattavuutta voidaan verrata luotettavasti saman palvelun tuottamiseen sisäisesti.
Identification-commitment inventory (ICI-Model): confirmatory factor analysis and construct validity
Resumo:
The aim of this study is to confirm the factorial structure of the Identification-Commitment Inventory (ICI) developed within the frame of the Human System Audit (HSA) (Quijano et al. in Revist Psicol Soc Apl 10(2):27-61, 2000; Pap Psicól Revist Col Of Psicó 29:92-106, 2008). Commitment and identification are understood by the HSA at an individual level as part of the quality of human processes and resources in an organization; and therefore as antecedents of important organizational outcomes, such as personnel turnover intentions, organizational citizenship behavior, etc. (Meyer et al. in J Org Behav 27:665-683, 2006). The theoretical integrative model which underlies ICI Quijano et al. (2000) was tested in a sample (N = 625) of workers in a Spanish public hospital. Confirmatory factor analysis through structural equation modeling was performed. Elliptical least square solution was chosen as estimator procedure on account of non-normal distribution of the variables. The results confirm the goodness of fit of an integrative model, which underlies the relation between Commitment and Identification, although each one is operatively different.
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Background: Mantle cell lymphoma (MCL) is genetically characterized by the t(11;14)(q13;q32) translocation and a high number of secondary chromosomal alterations. The contribution of DNA methylation to MCL lymphomagenesis is not well known. We sought to identify epigenetically silenced genes in these tumours that might have clinical relevance. Methodology/Principal Findings: To identify potential methylated genes in MCL we initially investigated seven MCL cell lines treated with epigenetic drugs and gene expression microarray profiling. The methylation status of selected candidate genes was validated by a quantitative assay and subsequently analyzed in a series of primary MCL (n=38). After pharmacological reversion we identified 252 potentially methylated genes. The methylation analysis of a subset of these genes (n=25) in the MCL cell lines and normal B lymphocytes confirmed that 80% of them were methylated in the cell lines but not in normal lymphocytes. The subsequent analysis in primary MCL identified five genes (SOX9,HOXA9,AHR,NR2F2 ,and ROBO1) frequently methylated in these tumours. The gene methylation events tended to occur in the same primary neoplasms and correlated with higher proliferation, increased number of chromosomal abnormalities, and shorter survival of the patients. Conclusions: We have identified a set of genes whose methylation degree and gene expression levels correlate with aggressive clinicopathological features of MCL. Our findings also suggest that a subset of MCL might show a CpG island methylator phenotype (CIMP) that may influence the behaviour of the tumours.
Resumo:
OBJECTIVE: As universal screening of hypertension performs poorly in childhood, targeted screening to children at higher risk of hypertension has been proposed. Our goal was to assess the performance of combined parental history of hypertension and overweight/obesity to identify children with hypertension. We estimated the sensitivity, specificity, negative and positive predictive values of overweight/obesity and parental history of hypertension for the identification of hypertension in children. DESIGN AND METHOD: We analyzed data from a school-based cross-sectional study including 5207 children aged 10 to 14 years from all public 6th grade classes in the canton of Vaud, Switzerland. Blood pressure was measured with a clinically validated oscillometric automated device over up to three visits separated by one week. Children had hypertension if they had sustained elevated blood pressure over the three visits. Parents were interviewed about their history of hypertension. RESULTS: The prevalence of hypertension was 2.2%. 14% of children were overweight or obese and 20% had a positive history of hypertension in either or both parents. 30% of children had either or both conditions. After accounting for several potential confounding factors, parental history of hypertension (odds ratio (OR): 2.6; 95% confidence interval (CI): 1.8-4.0), overweight excluding obesity (OR: 2.5; 95% CI: 1.5-4.2) and obesity (OR: 10.1; 95% CI: 6.0-17.0) were associated with hypertension in children. Considered in isolation, the sensitivity and positive predictive values of parental history of hypertension (respectively 41% and 5%) or overweight/obesity (respectively 43% and 7%) were relatively low. Nevertheless, considered together, the sensitivity of targeted screening in children with either overweight/obesity or paternal history of hypertension was higher (65%) but the positive predictive value remained low (5%). The negative predictive value was systematically high. CONCLUSIONS: Restricting screening of hypertension to children with either overweight/obesity or with hypertensive parents would substantially limit the proportion of children to screen (30%) and allow the identification of a relatively large proportion (65%) of hypertensive cases. That could be a valuable alternative to universal screening.
Resumo:
Drug combinations can improve angiostatic cancer treatment efficacy and enable the reduction of side effects and drug resistance. Combining drugs is non-trivial due to the high number of possibilities. We applied a feedback system control (FSC) technique with a population-based stochastic search algorithm to navigate through the large parametric space of nine angiostatic drugs at four concentrations to identify optimal low-dose drug combinations. This implied an iterative approach of in vitro testing of endothelial cell viability and algorithm-based analysis. The optimal synergistic drug combination, containing erlotinib, BEZ-235 and RAPTA-C, was reached in a small number of iterations. Final drug combinations showed enhanced endothelial cell specificity and synergistically inhibited proliferation (p < 0.001), but not migration of endothelial cells, and forced enhanced numbers of endothelial cells to undergo apoptosis (p < 0.01). Successful translation of this drug combination was achieved in two preclinical in vivo tumor models. Tumor growth was inhibited synergistically and significantly (p < 0.05 and p < 0.01, respectively) using reduced drug doses as compared to optimal single-drug concentrations. At the applied conditions, single-drug monotherapies had no or negligible activity in these models. We suggest that FSC can be used for rapid identification of effective, reduced dose, multi-drug combinations for the treatment of cancer and other diseases.
Resumo:
The avidity of the T-cell receptor (TCR) for antigenic peptides presented by the peptide-MHC (pMHC) on cells is a key parameter for cell-mediated immunity. Yet a fundamental feature of most tumor antigen-specific CD8(+) T cells is that this avidity is low. In this study, we addressed the need to identify and select tumor-specific CD8(+) T cells of highest avidity, which are of the greatest interest for adoptive cell therapy in patients with cancer. To identify these rare cells, we developed a peptide-MHC multimer technology, which uses reversible Ni(2+)-nitrilotriacetic acid histidine tags (NTAmers). NTAmers are highly stable but upon imidazole addition, they decay rapidly to pMHC monomers, allowing flow-cytometric-based measurements of monomeric TCR-pMHC dissociation rates of living CD8(+) T cells on a wide avidity spectrum. We documented strong correlations between NTAmer kinetic results and those obtained by surface plasmon resonance. Using NTAmers that were deficient for CD8 binding to pMHC, we found that CD8 itself stabilized the TCR-pMHC complex, prolonging the dissociation half-life several fold. Notably, our NTAmer technology accurately predicted the function of large panels of tumor-specific T cells that were isolated prospectively from patients with cancer. Overall, our results demonstrated that NTAmers are effective tools to isolate rare high-avidity cytotoxic T cells from patients for use in adoptive therapies for cancer treatment.
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Neuronal networks in vitro are prominent systems to study the development of connections in living neuronal networks and the interplay between connectivity, activity and function. These cultured networks show a rich spontaneous activity that evolves concurrently with the connectivity of the underlying network. In this work we monitor the development of neuronal cultures, and record their activity using calcium fluorescence imaging. We use spectral analysis to characterize global dynamical and structural traits of the neuronal cultures. We first observe that the power spectrum can be used as a signature of the state of the network, for instance when inhibition is active or silent, as well as a measure of the network's connectivity strength. Second, the power spectrum identifies prominent developmental changes in the network such as GABAA switch. And third, the analysis of the spatial distribution of the spectral density, in experiments with a controlled disintegration of the network through CNQX, an AMPA-glutamate receptor antagonist in excitatory neurons, reveals the existence of communities of strongly connected, highly active neurons that display synchronous oscillations. Our work illustrates the interest of spectral analysis for the study of in vitro networks, and its potential use as a network-state indicator, for instance to compare healthy and diseased neuronal networks.
Resumo:
In this paper we study the existence of a unique solution for linear stochastic differential equations driven by a Lévy process, where the initial condition and the coefficients are random and not necessarily adapted to the underlying filtration. Towards this end, we extend the method based on Girsanov transformations on Wiener space and developped by Buckdahn [7] to the canonical Lévy space, which is introduced in [25].