Monomial Gotzmann sets

Ankara : The Department of Mathematics and the Institute of Engineering and Science of Bilkent University, 2011.Thesis (Master's) -- Bilkent University, 2011.Includes bibliographical references leaves 21-22.A homogeneous set of monomials in a quotient of the polynomial ring S := F[x1, . . . , xn] is called Gotzmann if the size of this set grows minimally when multiplied with the variables. We note that Gotzmann sets in the quotient R := F[x1, . . . , xn]/(x a 1 ) arise from certain Gotzmann sets in S. Then we partition the monomials in a Gotzmann set in S with respect to the multiplicity of xi and obtain bounds on the size of a component in the partition depending on neighboring components. We show that if the growth of the size of a component is larger than the size of a neighboring component, then this component is a multiple of a Gotzmann set in F[x1, . . . , xi−1, xi+1, . . . xn]. We also adopt some properties of the minimal growth of the Hilbert function in S to R.Pir, Ata FıratM.S

A cross-cultural perspective on mothers’ attitudes on sharing information with the teachers on which child has been conceived by egg donation

There is now a growing body of research examining psychological aspects of children born as a result of Assisted Reproductive Technologies (ARTs), in particular via egg donation. Some research suggests that concealment of children’s biological origins may affect their psychological development. Hence, there is current debate to decide how widely details about children’s conception should be disclosed to the public in particular to those involved in the education of children. Some parents maintain that the school should be informed so that teachers can offer support to children that reveal details about their origin. Others think this information should be kept private. The present study is focused on the debate as to whether the private information about the children’s conception should be shared with their teachers. This will be studied from the point of view of mothers with naturally conceived children and mothers of children born as a result of egg donation. Furthermore, the topic will be investigated from a cross-cultural perspective. Mothers of children born as a result of egg donation from Iran (N =4) and Britain (N =4), overall mean age = 39.37, and 69 mothers with naturally conceived children from Iran (N = 33) and Britain (N = 36), overall mean age = 36.79, were asked if they would agree that information about how their child was born should be shared with their teachers. The results were an overwhelming disagreement from all women that this information should be shared with teachers. However, Iranian women with naturally born children differed from their British counterparts in being relatively more positive on this subject, possibly an indication that they do not agree with conception via egg donation. The implications of the results are discussed

Highly selective fluoride sensing via chromogenic aggregation of a silyloxy-functionalized tetraphenylethylene (TPE) derivative

Cataloged from PDF version of article.A silyloxy-functionalized tetraphenylethylene (TPE) derivative shows a remarkable change in the absorption spectrum on deprotection with fluoride ions. The reaction process is highly selective for fluoride and the resulting charge transfer band results in a bright green solution. A simple selective visual assay of aqueous fluoride ions was also obtained by the impregnation of cellulose strips with the TPE derivative

Haploinsufficiency and the sex chromosomes from yeasts to humans.

BACKGROUND: Haploinsufficient (HI) genes are those for which a reduction in copy number in a diploid from two to one results in significantly reduced fitness. Haploinsufficiency is increasingly implicated in human disease, and so predicting this phenotype could provide insights into the genetic mechanisms behind many human diseases, including some cancers. RESULTS: In the present work we show that orthologues of Saccharomyces cerevisiae HI genes are preferentially retained across the kingdom Fungi, and that the HI genes of S. cerevisiae can be used to predict haploinsufficiency in humans. Our HI gene predictions confirm known associations between haploinsufficiency and genetic disease, and predict several further disorders in which the phenotype may be relevant. Haploinsufficiency is also clearly relevant to the gene-dosage imbalances inherent in eukaryotic sex-determination systems. In S. cerevisiae, HI genes are over-represented on chromosome III, the chromosome that determines yeast's mating type. This may be a device to select against the loss of one copy of chromosome III from a diploid. We found that orthologues of S. cerevisiae HI genes are also over-represented on the mating-type chromosomes of other yeasts and filamentous fungi. In animals with heterogametic sex determination, accumulation of HI genes on the sex chromosomes would compromise fitness in both sexes, given X chromosome inactivation in females. We found that orthologues of S. cerevisiae HI genes are significantly under-represented on the X chromosomes of mammals and of Caenorhabditis elegans. There is no X inactivation in Drosophila melanogaster (increased expression of X in the male is used instead) and, in this species, we found no depletion of orthologues to yeast HI genes on the sex chromosomes. CONCLUSION: A special relationship between HI genes and the sex/mating-type chromosome extends from S. cerevisiae to Homo sapiens, with the microbe being a useful model for species throughout the evolutionary range. Furthermore, haploinsufficiency in yeast can predict the phenotype in higher organisms.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

How yeast re-programmes its transcriptional profile in response to different nutrient impulses.

BACKGROUND: A microorganism is able to adapt to changes in its physicochemical or nutritional environment and this is crucial for its survival. The yeast, Saccharomyces cerevisiae, has developed mechanisms to respond to such environmental changes in a rapid and effective manner; such responses may demand a widespread re-programming of gene activity. The dynamics of the re-organization of the cellular activities of S. cerevisiae in response to the sudden and transient removal of either carbon or nitrogen limitation has been studied by following both the short- and long-term changes in yeast's transcriptomic profiles. RESULTS: The study, which spans timescales from seconds to hours, has revealed the hierarchy of metabolic and genetic regulatory switches that allow yeast to adapt to, and recover from, a pulse of a previously limiting nutrient. At the transcriptome level, a glucose impulse evoked significant changes in the expression of genes concerned with glycolysis, carboxylic acid metabolism, oxidative phosphorylation, and nucleic acid and sulphur metabolism. In ammonium-limited cultures, an ammonium impulse resulted in the significant changes in the expression of genes involved in nitrogen metabolism and ion transport. Although both perturbations evoked significant changes in the expression of genes involved in the machinery and process of protein synthesis, the transcriptomic response was delayed and less complex in the case of an ammonium impulse. Analysis of the regulatory events by two different system-level, network-based approaches provided further information about dynamic organization of yeast cells as a response to a nutritional change. CONCLUSIONS: The study provided important information on the temporal organization of transcriptomic organization and underlying regulatory events as a response to both carbon and nitrogen impulse. It has also revealed the importance of a long-term dynamic analysis of the response to the relaxation of a nutritional limitation to understand the molecular basis of the cells' dynamic behaviour.The authors greatly acknowledge the financial support for the research from the BBSRC (Grant BB/C505140/1 to SGO), and the travel grants for DD kindly provided by the Research Council of Turkey (TUBITAK) through the BDP programme and the Turkish State Planning Organization DPT09K120520. The research was also financially supported by Bogazici University Research Fund through Project No 631 and TUBITAK through Project No 106M444. Further support came from European Commission though the Coordination Action Project YSBN (Contract No.018942 to both BK and SGO) and UNICELLSYS Collaborative Project (No. 201142 to SGO)

Genome-wide assessment of the carriers involved in the cellular uptake of drugs: a model system in yeast.

BACKGROUND: The uptake of drugs into cells has traditionally been considered to be predominantly via passive diffusion through the bilayer portion of the cell membrane. The recent recognition that drug uptake is mostly carrier-mediated raises the question of which drugs use which carriers. RESULTS: To answer this, we have constructed a chemical genomics platform built upon the yeast gene deletion collection, using competition experiments in batch fermenters and robotic automation of cytotoxicity screens, including protection by 'natural' substrates. Using these, we tested 26 different drugs and identified the carriers required for 18 of the drugs to gain entry into yeast cells. CONCLUSIONS: As well as providing a useful platform technology, these results further substantiate the notion that the cellular uptake of pharmaceutical drugs normally occurs via carrier-mediated transport and indicates that establishing the identity and tissue distribution of such carriers should be a major consideration in the design of safe and effective drugs.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

Conception by egg donation: perceptions, maternal bonding and health practices

Infertility is a condition that affects a significant number of couples around the world and Assisted Reproductive Technology (ART), which offers a range of possible treatments, is the most effective means to treat infertility. One of the key features of ART is conception by egg donation in which the child has no genetic link with the mother. The aim of the present thesis is to examine how the Iranian (Eastern) and British (Western) public, as well as mothers (both Iranian and British) who have conceived a child by egg donation, differ in their perceptions of the consequences of children born by egg donation from psychological, social and medical perspectives (study1). Furthermore, it aims to examine how Iranian pregnant women who have conceived by egg donation differ in their maternal bonding and health practices from those who conceived naturally (study 2). The sample group in study 1 consisted of 121 participants, 63 Iranian (Male = 26, Female = 37, Mean Age = 42.91, SD = 13.58) and 58 British (Male = 19, Female = 39, Mean Age = 32.36, SD = 14.02), in which 8 participants (4 Iranian and 4 British) were mothers with a donor egg child of primary school age. A 12-item questionnaire/statements was presented to the participants based on key reported literature on various scientific research findings on psychological, medical and social issues related to children born through ART. The participants were requested to respond to each statement by choosing one of the Likert scale options ranging from 1 to 4, Strongly agree, Agree, and Disagree to Strongly disagree. There was also an opportunity for the participants to write down additional comments in response to each of the statements about the reasons for their choice on each of the options. The process of data collection took 5 months to complete from January to May 2015. Study 1 results were subjected to quantitative analyses for the Iranian and the British public and for the Iranian and British mothers who have children born as a result of egg donation. Furthermore, all written comments were subjected to content analysis. The results showed that Iranian mothers with a donor egg child agreed more than their British counterparts (8 participants) that conception via egg donation might have psychological, social and medical problems for the resulting children due to a) lack of genetic link b) being unhappier than naturally born and c) might experience overt prejudice from the society. Overall, study 1 found that men more than women and the Iranians more than the British were in agreement with scientific research that children conceived via egg donation have more medical, psychological and social problems than naturally born children due to lack of genetic link, being unhappier and experience more prejudice from their society. Study 2 conducted in a hospital in Tehran aimed to explore maternal bonding between mother and fetus, and health practices in Iranian pregnant women via egg donation and naturally through the Maternal-Fetal Attachment (MFA), Fetal Health Locus of Control (FHLC) and Maternal Health Practices (MHP). The target group consisted of 21 Iranian women pregnant via egg donation (Mean Age = 32.42, SD = 4.48). For comparison, a sample of 50 women pregnant by natural conception (Mean Age = 28.06, SD = 5.45) was also recruited. The process of data collection initiated in January 2018 and concluded in May 2018. The results showed women who conceived via donor egg, compared to women who conceived naturally, scored lower on the 4 subscales of MFA namely: Attributing characteristics to the fetus, Giving of self, Differentiation of self from the fetus and Interaction with the fetus. On the FHLC scale, women who conceived via donor egg, compared to women who conceived naturally, considered both Chance and Professionals/Powerful Others (External factors) as being more responsible for the health of their baby rather than Internal factors (or themselves). Finally, women who conceived via donor egg, compared to women who conceived naturally, scored lower on MHP indicating they paid significantly less attention to their health activities during pregnancy. Overall, the results of the two studies are argued to make an original contribution to public perceptions of donor egg children and maternal bonding, and health practices of pregnant women who conceived by egg donation, in particular, in a culture such as Iran. It is hoped that practitioners and those involved in infertility treatment benefit from the results of the present study in giving the best advice to their patients. The limitations of the thesis, as well as recommendations and future directions, are discussed

A cross-cultural perspective on mothers’ attitudes on sharing information with the teachers on which child has been conceived by egg donation

There is now a growing body of research examining psychological aspects of children born as a result of Assisted Reproductive Technologies (ARTs), in particular via egg donation. Some research suggests that concealment of children’s biological origins may affect their psychological development. Hence, there is current debate to decide how widely details about children’s conception should be disclosed to the public in particular to those involved in the education of children. Some parents maintain that the school should be informed so that teachers can offer support to children that reveal details about their origin. Others think this information should be kept private. The present study is focused on the debate as to whether the private information about the children’s conception should be shared with their teachers. This will be studied from the point of view of mothers with naturally conceived children and mothers of children born as a result of egg donation. Furthermore, the topic will be investigated from a cross-cultural perspective. Mothers of children born as a result of egg donation from Iran (N =4) and Britain (N =4), overall mean age = 39.37, and 69 mothers with naturally conceived children from Iran (N = 33) and Britain (N = 36), overall mean age = 36.79, were asked if they would agree that information about how their child was born should be shared with their teachers. The results were an overwhelming disagreement from all women that this information should be shared with teachers. However, Iranian women with naturally born children differed from their British counterparts in being relatively more positive on this subject, possibly an indication that they do not agree with conception via egg donation. The implications of the results are discussed