998 resultados para Conceptual formation


Relevância:

20.00% 20.00%

Publicador:

Resumo:

ABSTRACT The present study aimed at evaluating the heterotic group formation in guava based on quantitative descriptors and using artificial neural network (ANN). For such, we evaluated eight quantitative descriptors. Large genetic variability was found for the eight quantitative traits in the 138 genotypes of guava. The artificial neural network technique determined that the optimal number of groups was three. The grouping consistency was determined by linear discriminant analysis, which obtained classification percentage of the groups, with a value of 86 %. It was concluded that the artificial neural network method is effective to detect genetic divergence and heterotic group formation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A drinking experiment with participants suffering from Gilbert's syndrome was performed to study the possible influence of this glucuronidation disorder on the formation of ethyl glucuronide (EtG). Gilbert's syndrome is a rather common and, in most cases, asymptomatic congenital metabolic aberration with a prevalence of about 5 %. It is characterized by a reduction of the enzyme activity of the uridine diphosphate glucuronosyltransferase (UGT) isoform 1A1 up to 80 %. One of the glucuronidation products is EtG, which is formed in the organism following exposure to ethanol. EtG is used as a short-term marker for ethyl alcohol consumption to prove abstinence in various settings. After 2 days of abstinence from ethanol and giving a void urine sample, 30 study participants drank 0.1 L of sparkling wine (9 g ethanol). 3, 6, 12, and 24 h after drinking, urine samples were collected. 3 hours after drinking, an additional blood sample was taken, in which liver enzyme activities, ethanol, hematological parameters, and bilirubin were measured. EtG and ethyl sulfate (EtS), another short-term marker of ethanol consumption, were determined in the urine samples using liquid chromatography-tandem mass spectrometry (LC-MS/MS); creatinine was measured photometrically. In all participants, EtG and EtS were detected in concentrations showing a wide range (EtG: 3 h sample 0.5-18.43 mg/L and 6 h sample 0.67-13.8 mg/L; EtS: 3 h sample 0.87-6.87 mg/L and 6 h sample 0.29-4.48 mg/L). No evidence of impaired EtG formation was found. Thus, EtG seems to be a suitable marker for ethanol consumption even in individuals with Gilbert's syndrome.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Cancer stem cells are cancer cells characterized by stem cell properties and represent a small population of tumor cells that drives tumor development, progression, metastasis and drug resistance. To date, the molecular mechanisms that generate and regulate cancer stem cells are not well defined. BORIS (Brother of Regulator of Imprinted Sites) or CTCFL (CTCF-like) is a DNA-binding protein that is expressed in normal tissues only in germ cells and is re-activated in tumors. Recent evidences have highlighted the correlation of BORIS/CTCFL expression with poor overall survival of different cancer patients. We have previously shown an association of BORIS-expressing cells with stemness gene expression in embryonic cancer cells. Here, we studied the role of BORIS in epithelial tumor cells. Using BORIS-molecular beacon that was already validated, we were able to show the presence of BORIS mRNA in cancer stem cell-enriched populations (side population and spheres) of cervical, colon and breast tumor cells. BORIS silencing studies showed a decrease of sphere formation capacity in breast and colon tumor cells. Importantly, BORIS-silencing led to down-regulation of hTERT, stem cell (NANOG, OCT4, SOX2 and BMI1) and cancer stem cell markers (ABCG2, CD44 and ALDH1) genes. Conversely, BORIS-induction led to up-regulation of the same genes. These phenotypes were observed in cervical, colon and invasive breast tumor cells. However, a completely different behavior was observed in the non-invasive breast tumor cells (MCF7). Indeed, these cells acquired an epithelial mesenchymal transition phenotype after BORIS silencing. Our results demonstrate that BORIS is associated with cancer stem cell-enriched populations of several epithelial tumor cells and the different phenotypes depend on the origin of tumor cells.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Työn tavoitteet Tutkimuksen tavoitteena oli selvittää strategisten allianssien rakentamiseen, johtamiseen ja hallinnointiin liittyviä ongelmia sekä toteutusmalleja. Tarkoituksena oli laatia case -yritykselle toimintaehdotus teorian ja tutkijan muodostaman näkemyksen pohjalta. Tutkimusmetodologia ja -menetelmät Tutkimusote on konstruktiivinen, vaikkakin se sisältää vahvasti käsiteanalyyttisiä piirteitä. Toimeksiantajana tutkimukselle oli Neste Markkinointi Oy, jonka kahden kumppanin kanssa muodostamia alliansseja tarkasteltiin erillisinä. Tutkimuksen empiirinen osa perustui teemahaastatteluihin. Tulokset ja päätelmät Strategisten allianssien muodostaminen vaatii yrityksiltä paljon työtä. Tutkimuksen tuloksena yritykselle esitettiin näkemys toiminnasta tulevaisuudessa sillä jo olevien kumppaneiden kanssa. Tehdyt havainnot liittyivät pääosin yhteistyön todelliseen aloittamiseen. Empiirinen osa vahvisti teoriassa muodostunutta näkemystä kumppanuuden rakentamisen vaikeudesta ja todellisen yhteistyön problematiikasta. Yleisesti teorian ja tutkimuksen pohjalta voidaan todeta strategisten allianssien olevan yksi mahdollinen avain yrityksen ylivoimaiseen kilpailukykyyn.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Single-stranded DNA (ssDNA) plays a major role in several biological processes. It is therefore of fundamental interest to understand how the elastic response and the formation of secondary structures are modulated by the interplay between base pairing and electrostatic interactions. Here we measure force-extension curves (FECs) of ssDNA molecules in optical tweezers set up over two orders of magnitude of monovalent and divalent salt conditions, and obtain its elastic parameters by fitting the FECs to semiflexible models of polymers. For both monovalent and divalent salts, we find that the electrostatic contribution to the persistence length is proportional to the Debye screening length, varying as the inverse of the square root of cation concentration. The intrinsic persistence length is equal to 0.7 nm for both types of salts, and the effectivity of divalent cations in screening electrostatic interactions appears to be 100-fold as compared with monovalent salt, in line with what has been recently reported for single-stranded RNA. Finally, we propose an analysis of the FECs using a model that accounts for the effective thickness of the filament at low salt condition and a simple phenomenological description that quantifies the formation of non-specific secondary structure at low forces.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We analyze the stability of small bubbles in a closed system with fixed volume, temperature, and number of molecules. We show that there exists a minimum stable size of a bubble. Thus there exists a range of densities where no stable bubbles are allowed and the system has a homogeneous density which is lower than the coexistence density of the liquid. This becomes possible due to the finite liquid compressibility. Capillary analysis within the developed"modified bubble" model illustrates that the existence of the minimum bubble size is associated to the compressibility and it is not possible when the liquid is strictly incompressible. This finding is expected to have very important implications in cavitation and boiling.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

En aquest article desenvolupem una aproximació als sectors i àmbits d'intervenció de l'educació social. Pensem, però, que és bo que, en primer lloc, intentem definir què és el que entenem per educació social i pedagogia social.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Es comprensible que cuando hablamos de los diagnósticos enfermeros se produzcan confusiones terminológicas puesto que, según el Diccionario de la Real Academia de la Lengua Española, la primera acepción de la palabra diagnóstico es «perteneciente o relativo a la diagnosis. Conjunto de signos que sirven para fijar la naturaleza de una enfermedad». Por tanto, debemos...