910 resultados para Colour polymorphism


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Pigmenttipäällystyksen tarkoituksena on parantaa painopapereiden pintaominaisuuksia. Tämän työn tarkoituksena oli löytää sopiva päällystyspasta päällystetylle coldset-paperille. Kirjallisuusosassa on käsitelty coldset-painatusta ja sen ongelmia. Päällystysmenetelmän perusteita, pastan ominaisuuksia ja niiden vaikutusta päällystystulokseen on myös käsitelty. Lisäksi on esitelty joitakin päällystetyn paperin pinnantutkimusmenetelmiä. Kokeellisessa osassa on tutkittu erilaisten pastakoostumusten ja päällystemäärien sekä kalanteroinnin vaikutusta paperin painettavuuteen. Paperit on päällystetty Helicoaterilla ja joitakin pastoja on testattu myös pilot-mittakaavaisessa päällystyksessä. Selitystä paperin käyttäytymiseen painatuksessa on etsitty päällystetyn paperin pintarakenteesta. Paras painettavuus saavutetaan päällysteellä, jossa pigmenttinä on vain karbonaatti. Painojälkeä voidaan parantaa käyttämällä kalsinoitua kaoliinia yhdessä karbonaatin kanssa, mutta tämän päällysteen pintalujuus ei ole riittävä CSWO-painatukseen. Tärkkipigmentti parantaa veden ja painovärin absorptiota ja siten tekee painetun tuotteen kuivemmaksi ja miellyttävämmän tuntuiseksi, mutta aiheuttaa smearingia. Tämä johtuu liian nopeasta musteen asettuvuudesta. "Pehmeä" SB-lateksi soveltuu paremmin offset-painatukseen kuin "kova" lateksi, joka sisältää myös PVAc:ta. "Pehmeällä" lateksilla saadaan parempi pintalujuus ja painojälki kuin "kovalla" lateksilla. Paperin pölyävyyttä painatuksessa voidaan vähentää nostamalla päällystemäärää ja laskemalla pastan kuiva-ainepitoisuutta. Kalanteroinnilla ei pintalujuutta tai painojälkeä voida parantaa. Selitys tutkimuksessa käsiteltyjen papereiden painojäljelle ja painettavuudelle löydetään tutkimalla päällysteen pintarakennetta. Painojälkeen vaikuttaa eniten päällysteen peittoaste. Huonoa peittävyyttä voidaan parantaa nostamalla päällystemäärää. Pölyäminen painatuksessa johtuu pigmenteistä, jotka eivät ole sidottuja paperin pintaan. Tämä taas johtuu pastan huonosta vesiretentiosta. Hyödyllisintä tietoa näiden papereiden pintarakenteesta saadaan tutkimalla pintaa pyyhkäisyelektonimikroskoopilla (SEM), atomivoimamikroskoopilla (AFM) ja laserindusoidulla plasmaspektrometrilla (LIPS). LIPSin etuna on se, että päällystemääräjaukauma voidaan määrittää sekä x-y- että z-suunnassa samanaikaisesti samasta kohdasta. LIPSissä myös näytteen preparointitarve on hyvin vähäinen.

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The β site APP cleaving enzyme 1 (BACE1) is the rate-limiting β-secretase enzyme in the amyloidogenic processing of APP and Aβ formation, and therefore it has a prominent role in Alzheimer"s disease (AD) pathology. Recent evidence suggests that the prion protein (PrP) interacts directly with BACE1 regulating its β-secretase activity. Moreover, PrP has been proposed as the cellular receptor involved in the impairment of synaptic plasticity and toxicity caused by Aβ oligomers. Provided that common pathophysiologic mechanisms are shared by Alzheimer"s and Creutzfeldt-Jakob (CJD) diseases, we investigated for the first time to the best of our knowledge a possible association of a common synonymous BACE1 polymorphism (rs638405) with sporadic CJD (sCJD). Our results indicate that BACE1 C-allele is associated with an increased risk for developing sCJD, mainly in PRNP M129M homozygous subjects with early onset. These results extend the very short list of genes (other than PRNP) involved in the development of human prion diseases; and support the notion that similar to AD, in sCJD several loci may contribute with modest overall effects to disease risk. These findings underscore the interplay in both pathologies of APP, Aβ oligomers, ApoE, PrP and BACE1, and suggest that aging and perhaps vascular risk factors may modulate disease pathologies in part through these key players

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The interplay between selection and aspects of the genetic architecture of traits (such as linkage, dominance, and epistasis) can either drive or constrain speciation [1-3]. Despite accumulating evidence that speciation can progress to "intermediate" stages-with populations evolving only partial reproductive isolation-studies describing selective mechanisms that impose constraints on speciation are more rare than those describing drivers. The stick insect Timema cristinae provides an example of a system in which partial reproductive isolation has evolved between populations adapted to different host plant environments, in part due to divergent selection acting on a pattern polymorphism [4, 5]. Here, we demonstrate how selection on a green/melanistic color polymorphism counteracts speciation in this system. Specifically, divergent selection between hosts does not occur on color phenotypes because melanistic T. cristinae are cryptic on the stems of both host species, are resistant to a fungal pathogen, and have a mating advantage. Using genetic crosses and genome-wide association mapping, we quantify the genetic architecture of both the pattern and color polymorphism, illustrating their simple genetic control. We use these empirical results to develop an individual-based model that shows how the melanistic phenotype acts as a "genetic bridge" that increases gene flow between populations living on different hosts. Our results demonstrate how variation in the nature of selection acting on traits, and aspects of trait genetic architecture, can impose constraints on both local adaptation and speciation.

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Seizures associated with fever are a common pediatric problem, affecting about 2-7 % of children between 3 months and 5 years of age. Differentiation of febrile seizures from acute symptomatic seizures secondary to central nervous system infections or seizures associated with fever in children with epilepsy is essential to provide appropriate treatment and follow-up care. Here, we tested the hypothesis that children who exhibit simple febrile seizures during early childhood, but do not develop epileptic seizures later in life, might preferentially carry the ApoE2 allele of the gene coding for the apolipoprotein E. We did not find any differences in the distribution of ApoE alleles or genotypes between individuals who exhibited simple febrile seizures (n = 93) and age-matched, typically developing subjects (n = 80). We found that the observed allele and genotype frequencies did not deviate from Hardy-Weinberg equilibrium, which suggests that the frequencies of ApoE alleles and genotypes are stable in the Swiss population from which our samples were derived. Across both groups of subjects (n = 173), we found an ApoE2 allele frequency of 0.064, an ApoE3 frequency of 0.829 and an ApoE4 frequency of 0.107. Our findings are consistent with previous reports of the distribution of ApoE polymorphism for European subjects free of any neurological disorders, and show that the different alleles of the gene coding for the apolipoprotein E are not associated with the occurrence of simple febrile seizures.

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A rare germ-line polymorphism in codon 47 of the p53 gene replaces the wild-type proline (CCG) with a serine (TCG). Restriction analysis of 101 human samples revealed the frequency of the rare allele to be 0% (n = 69) in Caucasians and 4.7% (3/64, n = 32) among African-Americans. To investigate the consequence of this amino acid substitution, a cDNA construct (p53 mut47ser) containing the mutation was introduced into a lung adenocarcinoma cell line (Calu-6) that does not express p53. A growth suppression similar to that obtained after introduction of a wild-type p53 cDNA construct was observed, in contrast to the result obtained by introduction of p53 mut143ala. Furthermore, expression of neither p53 mut47ser nor wild-type p53 was tolerated by growing cells. In transient expression assays, both mut47ser and wild-type p53 activated the expression of a reporter gene linked to a p53 binding sequence (PG13-CAT) and inhibited the expression of the luciferase gene under the control of the Rous sarcoma virus promoter (RSVluc). In the same assay, mut143ala did not activate the expression of PG13-CAT and produced only a slight inhibitory effect on RSVluc. These findings indicate that the p53 variant with a serine at codon 47 should be considered as a rare germ-line polymorphism that does not alter the growth-suppression activity of p53.

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NlmCategory="UNASSIGNED">Metabolic syndrome after transplantation is a major concern following solid organ transplantation (SOT). The CREB-regulated transcription co-activator 2 (CRTC2) regulates glucose metabolism. The effect of CRTC2 polymorphisms on new-onset diabetes after transplantation (NODAT) was investigated in a discovery sample of SOT recipients (n1=197). Positive results were tested for replication in two samples from the Swiss Transplant Cohort Study (STCS, n2=1294 and n3=759). Obesity and other metabolic traits were also tested. Associations with metabolic traits in population-based samples (n4=46'186, n5=123'865, n6>100,000) were finally analyzed. In the discovery sample, CRTC2 rs8450-AA genotype was associated with NODAT, fasting blood glucose and body mass index (Pcorrected<0.05). CRTC2 rs8450-AA genotype was associated with NODAT in the second STCS replication sample (odd ratio (OR)=2.01, P=0.04). In the combined STCS replication samples, the effect of rs8450-AA genotype on NODAT was observed in patients having received SOT from a deceased donor and treated with tacrolimus (n=395, OR=2.08, P=0.02) and in non-kidney transplant recipients (OR=2.09, P=0.02). Moreover, rs8450-AA genotype was associated with overweight or obesity (n=1215, OR=1.56, P=0.02), new-onset hyperlipidemia (n=1007, OR=1.76, P=0.007), and lower high-density lipoprotein-cholesterol (n=1214, β=-0.08, P=0.001). In the population-based samples, a proxy of rs8450G>A was significantly associated with several metabolic abnormalities. CRTC2 rs8450G>A appears to have an important role in the high prevalence of metabolic traits observed in patients with SOT. A weak association with metabolic traits was also observed in the population-based samples.The Pharmacogenomics Journal advance online publication, 8 December 2015; doi:10.1038/tpj.2015.82.

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Barn owl (Tyto alba) siblings preen and offer food items to one another, behaviours that can be considered prosocial because they benefit a conspecific by relieving distress or need. In experimental broods, we analysed whether such behaviours were reciprocated, preferentially exchanged between specific phenotypes, performed to avoid harassment and food theft or signals of hierarchy status. Three of the results are consistent with the hypothesis of direct reciprocity. First, food sharing was reciprocated in three-chick broods but not in pairs of siblings, that is when nestlings could choose a partner with whom to develop a reciprocating interaction. Second, a nestling was more likely to give a prey item to its sibling if the latter individual had preened the former. Third, siblings matched their investment in preening each other. Manipulation of age hierarchy showed that food stealing was directed towards older siblings but was not performed to compensate for a low level of cooperation received. Social behaviours were related to melanin-based coloration, suggesting that animals may signal their propensity to interact socially. The most prosocial phenotype (darker reddish) was also the phenotype that stole more food, and the effect of coloration on prosocial behaviour depended upon rank and sex, suggesting that colour-related prosociality is state dependent.

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Humans like some colours and dislike others, but which particular colours and why remains to be understood. Empirical studies on colour preferences generally targeted most preferred colours, but rarely least preferred (disliked) colours. In addition, findings are often based on general colour preferences leaving open the question whether results generalise to specific objects. Here, 88 participants selected the colours they preferred most and least for three context conditions (general, interior walls, t-shirt) using a high-precision colour picker. Participants also indicated whether they associated their colour choice to a valenced object or concept. The chosen colours varied widely between individuals and contexts and so did the reasons for their choices. Consistent patterns also emerged, as most preferred colours in general were more chromatic, while for walls they were lighter and for t-shirts they were darker and less chromatic compared to least preferred colours. This meant that general colour preferences could not explain object specific colour preferences. Measures of the selection process further revealed that, compared to most preferred colours, least preferred colours were chosen more quickly and were less often linked to valenced objects or concepts. The high intra- and inter-individual variability in this and previous reports furthers our understanding that colour preferences are determined by subjective experiences and that most and least preferred colours are not processed equally.

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When analyzing the chromosomal polymorphism of D. subobscura natural populations it is assumed that the information provided by wild males and sons of wild females is equivalent. Thus, using both in the analysis it is possible to increase the sample size. However, it is important to verify whether there are significant differences between both groups or not. The aim of this research has been to statistically compare the results of chromosomal polymorphism of both groups. We have used data from Avala Mountain (Serbia) where D. subobscura flies were collected from the 30th May to the 5th June 2011. Avala is located 18 km south of Belgrade and the trapping place is a forest with polydominant communities of Fagetum submontanum Table 1. Number and percentage of adult flies collected in Font Groga (Barcelona, Spain) on 9th October 2013. Males and sons of wild females were crossed with virgin females of the Küsnacht strain. Third instar larvae from F1 were dissected to obtain the salivary glands and the polytene chromosomes were stained and squashed in aceto-orcein solution. No significant differences were observed for any chromosome of the karyotype: A (p-value = 0.485), J (p-value = 0.230), U (p-value =0.572), E (p-value = 0.536), and O (p-value = 0.338). Thus, it seems that the two groups can be grouped together to obtain the chromosomal polymorphism of the population.

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In this paper a colour texture segmentation method, which unifies region and boundary information, is proposed. The algorithm uses a coarse detection of the perceptual (colour and texture) edges of the image to adequately place and initialise a set of active regions. Colour texture of regions is modelled by the conjunction of non-parametric techniques of kernel density estimation (which allow to estimate the colour behaviour) and classical co-occurrence matrix based texture features. Therefore, region information is defined and accurate boundary information can be extracted to guide the segmentation process. Regions concurrently compete for the image pixels in order to segment the whole image taking both information sources into account. Furthermore, experimental results are shown which prove the performance of the proposed method

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Neuropeptide Y (NPY) is a widely expressed neurotransmitter in the central and peripheral nervous systems. Thymidine 1128 to cytocine substitution in the signal sequence of the preproNPY results in a single amino acid change where leucine is changed to proline. This L7P change leads to a conformational change of the signal sequence which can have an effect on the intracellular processing of NPY. The L7P polymorphism was originally associated with higher total and LDL cholesterol levels in obese subjects. It has also been associated with several other physiological and pathophysiological responses such as atherosclerosis and T2 diabetes. However, the changes on the cellular level due to the preproNPY signal sequence L7P polymorphism were not known. The aims of the current thesis were to study the effects of the [p.L7]+[p.L7] and the [p.L7]+[p.P7] genotypes in primary cultured and genotyped human umbilical vein endothelial cells (HUVEC), in neuroblastoma (SK-N-BE(2)) cells and in fibroblast (CHO-K1) cells. Also, the putative effects of the L7P polymorphism on proliferation, apoptosis and LDL and nitric oxide metabolism were investigated. In the course of the studies a fragment of NPY targeted to mitochondria was found. With the putative mitochondrial NPY fragment the aim was to study the translational preferences and the mobility of the protein. The intracellular distribution of NPY between the [p.L7]+[p.L7] and the [p.L7]+[p.P7] genotypes was found to be different. NPY immunoreactivity was prominent in the [p.L7]+[p.P7] cells while the proNPY immunoreactivity was prominent in the [p.L7]+[p.L7] genotype cells. In the proliferation experiments there was a difference in the [p.L7]+[p.L7] genotype cells between early and late passage (aged) cells; the proliferation was raised in the aged cells. NPY increased the growth of the cells with the [p.L7]+[p.P7] genotype. Apoptosis did not seem to differ between the genotypes, but in the aged cells with the [p.L7]+[p.L7] genotype, LDL uptake was found to be elevated. Furthermore, the genotype seemed to have a strong effect on the nitric oxide metabolism. The results indicated that the mobility of NPY protein inside the cells was increased within the P7 containing constructs. The existence of the mitochondria targeted NPY fragment was verified, and translational preferences were proved to be due to the origin of the cells. Cell of neuronal origin preferred the translation of mature NPY (NPY1-36) when compared to the non neuronal cells that translated both, NPY and the mitochondrial fragment of NPY. The mobility of the mitochondrial fragment was found to be minimal. The functionality of the mitochondrial NPY fragment remains to be investigated. L7P polymorphism in the preproNPY causes a series of intracellular changes. These changes may contribute to the state of cellular senescence, vascular tone and lead to endothelial dysfunction and even to increased susceptibility to diseases, like atherosclerosis and T2 diabetes.

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A common feature of natural populations is that individuals differ in morphology, physiologyand behavior (i.e .phenotype). A thorough understanding of the molecular mechanisms and evolutionary forces behind this phenotypic variation is a prerequisite for understanding evolution.This thesis examines the molecular mechanism and the roles of the different evolutionary forces in plumage colour variation in pied flycatchers (Ficedulahypoleuca). Malepied flycatchers exhibit marked variation in both pigmentary and structural plumage colourand the trait has repeatedly been suggested to be of adaptive significance. An examination of plumage colour variation on reproductive output trevealed that structural colouration, and more specifically the degree of ultraviolet (UV) reflectance had an effect on number of young sired. Paternity analyses of breeding males revealed that males that had been cuckolded by their social mate tended to be less UV reflectant than males that had not been cuckolded.Neither pigment-based norstructural colouration was found to affect the probability of siring young in other nests. Phenotypic differentiation was found to be markedly greater than differentiation at neutralgenetic markers across the pied flycatcher breeding range. Furthermore patterns of differentiationin phenotypes and selectively neutral genes were not uniform. Outlier tests searching for genomic footprints of selection revealed elevated levels of genetic divergence in a gene associated with feather development (and thus potentially structural colouration) and ultraviolet vision. Th eobserved differentiation in allelic frequencies was particularly pronounced in the Spanish piedflycatcher populations. Examining gene expression during feather development indicated that the TYRP1 gene (known to be involved in the production of black pigment) may be relevant in generating phenotypic variation in pied flycatcher plumage. Also, energy homeostasis related genesfeatured prominently among the genes found to be expressed in one extreme phenotype but not the other. This is of particular interest in light of what is known about the pleiotropy ofthe melanocortin system which underlies brown-black pigment production. The melanocortinsystem is also associated with energy homeostasis (among a number of other physiological functions) and thus the results could be pointing to the signalling function of brown-blackplumage. Plumage colour variation in pied flycatchers, both structural and pigmentary, can thus beconcluded to be exhibiting signals of non-neutral evolution. Structural colouration was found to play a role in sexual selection and putative signals of selection were further detected in acandidate gene for this trait. Evidence for non-neutral evolution of pigmentary colouration was also detected. These findings, together with the fact that preliminary evidence for an energy balance associated signalling function for plumage was found, present good starting points for further investigations into the meaning and mechanisms of plumage colour variation in piedflycatchers.

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Palm oil is one of the two most important vegetable oils in the world's oil and fats market. The extraction and purification processes generate different kinds of waste generally known as palm oil mill effluent (POME). Earlier studies had indicated the possibility of using boiler fly ash to adsorb impurities and colour in POME treatment. The adsorption treatment of POME using boiler fly ash was further investigated in detail in this work with regards to the reduction of BOD, colour and TSS from palm oil mill effluent. The amount of BOD, colour and TSS adsorbed increased as the weight of the boiler fly ash used was increased. Also, the smaller particle size of 425µm adsorbed more than the 850µm size. Attempts were made to fit the experimental data with the Freundlich, Langmuir and Dubinin-Radushkevich isotherms. The R² values, which ranged from 0.8974-0.9898, 0.8848-0.9824 and 0.6235-0.9101 for Freundlich, Langmuir and Dubinin-Radushkevich isotherms respectively, showed that Freundlich isotherm gave a better fit followed by Langmuir and then Dubinin-Radushkevich isotherm. The sorption trend could be put as BOD > Colour > TSS. The apparent energy of adsorption was found to be 1.25, 0.58 and 0.97 (KJ/mol) for BOD, colour and TSS respectively, showing that sorption process occurs by physiosorption. Therefore, boiler fly ash is capable of reducing BOD, Colour and TSS from POME and hence could be used to develop a good adsorbent for POME treatment.