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Search Results: 1 - 10 of 467998 matches for " Elizabeth A Rach "
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The Drosophila Translational Control Element (TCE) Is Required for High-Level Transcription of Many Genes That Are Specifically Expressed in Testes
Rebeccah J. Katzenberger,Elizabeth A. Rach,Ashley K. Anderson,Uwe Ohler,David A. Wassarman
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0045009
Abstract: To investigate the importance of core promoter elements for tissue-specific transcription of RNA polymerase II genes, we examined testis-specific transcription in Drosophila melanogaster. Bioinformatic analyses of core promoter sequences from 190 genes that are specifically expressed in testes identified a 10 bp A/T-rich motif that is identical to the translational control element (TCE). The TCE functions in the 5′ untranslated region of Mst(3)CGP mRNAs to repress translation, and it also functions in a heterologous gene to regulate transcription. We found that among genes with focused initiation patterns, the TCE is significantly enriched in core promoters of genes that are specifically expressed in testes but not in core promoters of genes that are specifically expressed in other tissues. The TCE is variably located in core promoters and is conserved in melanogaster subgroup species, but conservation dramatically drops in more distant species. In transgenic flies, short (300–400 bp) genomic regions containing a TCE directed testis-specific transcription of a reporter gene. Mutation of the TCE significantly reduced but did not abolish reporter gene transcription indicating that the TCE is important but not essential for transcription activation. Finally, mutation of testis-specific TFIID (tTFIID) subunits significantly reduced the transcription of a subset of endogenous TCE-containing but not TCE-lacking genes, suggesting that tTFIID activity is limited to TCE-containing genes but that tTFIID is not an obligatory regulator of TCE-containing genes. Thus, the TCE is a core promoter element in a subset of genes that are specifically expressed in testes. Furthermore, the TCE regulates transcription in the context of short genomic regions, from variable locations in the core promoter, and both dependently and independently of tTFIID. These findings set the stage for determining the mechanism by which the TCE regulates testis-specific transcription and understanding the dual role of the TCE in translational and transcriptional regulation.
Motif composition, conservation and condition-specificity of single and alternative transcription start sites in the Drosophila genome
Elizabeth A Rach, Hsiang-Yu Yuan, William H Majoros, Pavel Tomancak, Uwe Ohler
Genome Biology , 2009, DOI: 10.1186/gb-2009-10-7-r73
Abstract: To identify TSSs in Drosophila melanogaster, we applied a hierarchical clustering strategy on available 5' expressed sequence tags (ESTs) and identified a high quality set of 5,665 TSSs for approximately 4,000 genes. We distinguished two initiation patterns: 'peaked' TSSs, and 'broad' TSS cluster groups. Peaked promoters were found to contain location-specific sequence elements; conversely, broad promoters were associated with non-location-specific elements. In alignments across other Drosophila genomes, conservation levels of sequence elements exceeded 90% within the melanogaster subgroup, but dropped considerably for distal species. Elements in broad promoters had lower levels of conservation than those in peaked promoters. When characterizing the distributions of ESTs, 64% of TSSs showed distinct associations to one out of eight different spatiotemporal conditions. Available whole-genome tiling array time series data revealed different temporal patterns of embryonic activity across the majority of genes with distinct alternative promoters. Many genes with maternally inherited transcripts were found to have alternative promoters utilized later in development. Core promoters of maternally inherited transcripts showed differences in motif composition compared to zygotically active promoters.Our study provides a comprehensive map of Drosophila TSSs and the conditions under which they are utilized. Distinct differences in motif associations with initiation pattern and spatiotemporal utilization illustrate the complex regulatory code of transcription initiation.Transcription is a crucial part of gene expression that involves complex interactions of cis-regulatory sequence elements and trans-factors. It is mediated in large part through the binding of transcription factors (TFs) to DNA sequence motifs. The majority of eukaryotic genes (protein-coding genes and many regulatory RNAs) are transcribed by RNA polymerase II (RNA pol II), an enzyme that contains various subuni
Transcription Initiation Patterns Indicate Divergent Strategies for Gene Regulation at the Chromatin Level
Elizabeth A. Rach equal contributor,Deborah R. Winter equal contributor,Ashlee M. Benjamin,David L. Corcoran,Ting Ni,Jun Zhu,Uwe Ohler
PLOS Genetics , 2011, DOI: 10.1371/journal.pgen.1001274
Abstract: The application of deep sequencing to map 5′ capped transcripts has confirmed the existence of at least two distinct promoter classes in metazoans: “focused” promoters with transcription start sites (TSSs) that occur in a narrowly defined genomic span and “dispersed” promoters with TSSs that are spread over a larger window. Previous studies have explored the presence of genomic features, such as CpG islands and sequence motifs, in these promoter classes, but virtually no studies have directly investigated the relationship with chromatin features. Here, we show that promoter classes are significantly differentiated by nucleosome organization and chromatin structure. Dispersed promoters display higher associations with well-positioned nucleosomes downstream of the TSS and a more clearly defined nucleosome free region upstream, while focused promoters have a less organized nucleosome structure, yet higher presence of RNA polymerase II. These differences extend to histone variants (H2A.Z) and marks (H3K4 methylation), as well as insulator binding (such as CTCF), independent of the expression levels of affected genes. Notably, differences are conserved across mammals and flies, and they provide for a clearer separation of promoter architectures than the presence and absence of CpG islands or the occurrence of stalled RNA polymerase. Computational models support the stronger contribution of chromatin features to the definition of dispersed promoters compared to focused start sites. Our results show that promoter classes defined from 5′ capped transcripts not only reflect differences in the initiation process at the core promoter but also are indicative of divergent transcriptional programs established within gene-proximal nucleosome organization.
Issues in the Planning and Design of a Bilingual (English–Northern Sotho) Explanatory Dictionary for Industrial Electronics
Elsabé Taljard,Rachélle Gauton,Liam A. Gauton
Lexikos , 2011, DOI: 10.5788/17--516
Abstract: : The focus of this article is the planning and design of a bilingual, explanatory dictionary for industrial electronics with a clearly delimited and very specific target user in mind. Since the number of lemmas to be treated in the dictionary is limited to 500, special care must be taken to select those lemmas that are relevant for both the purpose of the dictionary and the needs of the target user. It is indicated that the main consideration in the planning of the envisaged dictionary is user-friendliness, as dictated by the intended target users. In this article, a novel approach to the semi-automatic selection of lemmas for inclusion in an LSP dictionary is described. The procedure that is used for the extraction of definitional information from an electronic corpus is also explained. Keywords: LSP LEXICOGRAPHY, DICTIONARY PLANNING, LEMMA SELECTION, SEMI-AUTOMATIC TERM EXTRACTION, DEFINITIONAL INFORMATION, INDUSTRIAL ELEC-TRONICS, CORPUS-BASED LEXICOGRAPHY Opsomming: Kwessies by die beplanning en ontwerp van 'n tweetalige (Engels–Noord-Sotho) verklarende woordeboek vir industri le elektronika. Die fokus van hierdie artikel is die beplanning en ontwerp van 'n tweetalige, verklarende woorde-boek vir industri le elektronika met 'n duidelik afgebakende en baie spesifieke teikengebruiker in gedagte. Aangesien die getal lemmas vir behandeling in die woordeboek tot 500 beperk is, moet besondere sorg gedra word dat daardie lemmas gekies word wat beantwoord aan die doel van die woordeboek én die behoeftes van die teikengebruiker. Daar word uitgewys dat die hoofoorweging in die beplanning van die beoogde woordeboek gebruikersvriendelikheid is, soos bepaal deur die bestemde teikengebruikers. In hierdie artikel word 'n nuwe benadering tot die semi-outomatiese keuse van lemmas vir insluiting in 'n vakwoordeboek beskryf. Die prosedure wat vir die onttrek-king van definisi le inligting uit 'n elektroniese korpus gebruik word, word ook verduidelik. Sleutelwoorde: LEKSIKOGRAFIE VIR VAKWOORDEBOEKE, WOORDEBOEKBEPLAN-NING, LEMMASELEKSIE, SEMI-OUTOMATIESE TERMONTTREKKING, DEFINISI LE INLIG-TING, INDUSTRI LE ELEKTRONIKA, KORPUS-GEBASEERDE LEKSIKOGRAFIE
Asymptotic Formula for Oscillatory Solutions of Some Singular Nonlinear Differential Equation
Irena Rach nková,Luká Rach nek
Abstract and Applied Analysis , 2011, DOI: 10.1155/2011/981401
Abstract: Singular differential equation (())=()() is investigated. Here is Lipschitz continuous on ℝ and has at least two zeros 0 and >0 . The function is continuous on [0,∞) and has a positive continuous derivative on (0,∞) and (0)=0. An asymptotic formula for oscillatory solutions is derived.
Strictly Increasing Solutions of Nonautonomous Difference Equations Arising in Hydrodynamics
Rach?nek Luká?,Rach?nková Irena
Advances in Difference Equations , 2010,
Abstract: The paper provides conditions sufficient for the existence of strictly increasing solutions of the second-order nonautonomous difference equation , , where is a parameter and is Lipschitz continuous and has three real zeros . In particular we prove that for each sufficiently small there exists a solution such that is increasing, and . The problem is motivated by some models arising in hydrodynamics.
Bilingual Dictionaries, the Lexicographer and the Translator
Rachélle Gauton
Lexikos , 2011, DOI: 10.5788/18--479
Abstract: : This article focuses on the problems, and advantages and disadvantages of the bilingual dictionary from both the lexicographer's and the translator's point of view, with specific reference to bilingual Zulu dictionaries. It is shown that there are many and varying problems the lexicographer has to deal with and take cognisance of when compiling a translation dictionary. Of these, the main problem is the basic lack of equivalence or anisomorphism which exists between languages. This non-equivalence between languages is also the root cause of the difficulties with which the translator or user of the bilingual dictionary has to contend. The problems experienced by translators therefore overlap to a great extent with those which the lexicographer experiences in compiling a bilingual dictionary. It is concluded that the user of a bilingual dictionary should not only know what to expect to find in a translation dictionary, but must also treat such a dictionary with caution and discernment. It is also shown that there are clear criteria which the lexicographer can follow in compiling a bilingual dictionary, which would then enable the user (and in particular the translator as user) to disambiguate the recorded information successfully. Keywords: BILINGUAL DICTIONARIES, LEXICOGRAPHER, TRANSLATOR, ISIZULU,PROBLEMS EXPERIENCED BY LEXICOGRAPHERS, PROBLEMS EXPERIENCED BY TRANSLATORS,NONEQUIVALENCE BETWEEN LANGUAGES, CHARACTER, SHORTCOMINGSAND ADVANTAGES OF BILINGUAL DICTIONARIES Opsomming: Tweetalige woordeboeke, die leksikograaf en die vertaler.Die fokus van hierdie artikel is op die probleme, en voor- en nadele van die tweetalige woordeboekvanuit die oogpunt van sowel die leksikograaf as die vertaler, met spesifieke verwysing na tweetaligeZuluwoordeboeke. Daar word aangetoon dat daar baie en uiteenlopende probleme is waaraandie leksikograaf moet aandag gee en waarvan hy/sy moet kennis neem by die samestelling van 'nvertalende woordeboek. Die vernaamste van hierdie probleme is die basiese gebrek aan ekwivalensieof anisomorfisme wat tussen tale bestaan. Hierdie nie-ekwivalensie tussen tale is ook diegrondoorsaak van die moeilikhede waarmee die vertaler of gebruiker van die tweetalige woordeboekmoet worstel. Die probleme ondervind deur vertalers oorvleuel dus tot 'n groot mate met diéwat die leksikograaf ondervind by die samestellling van 'n tweetalige woordeboek. Daar word totdie slotsom gekom dat die gebruiker van 'n tweetalige woordeboek nie net moet weet wat om van'n vertalende woordeboek te verwag nie, maar ook so 'n woordeboek omsigtig en oordeelkund
Nintendo® Wii™ and a Physical Activity Routine: Effective Therapeutic Interventions in the Older Adult Population?  [PDF]
Elizabeth A. Fain, Brenda Kennell
Open Journal of Nursing (OJN) , 2014, DOI: 10.4236/ojn.2014.48060
Abstract:

Occupational therapists work with individuals across the lifespan to promote health and wellness. “Occupational therapy promotes health and wellbeing through active involvement in meaningful occupations. By helping clients eliminate barriers, enhance their self-management skills, improve their performance of daily activities and adopt healthy habits and routines, occupational therapy unlocks the door to participation across the lifespan” (AOTA, 2010). In today’s world, health and wellness-related services are in demand for those aged 65 and older. As life expectancy rates continue to rise, there is an increase in concern for the field of occupational therapy to find a successful and efficient way to meet the needs of the growing number of older adults (National Center for Health Statistics, 2006). The idea that physical activity can be a beneficial occupation in the elderly has been examined and proved effective as a means of enhancing the quality of life in this population. “Although functional impairments due to the aging process seem to be inevitable, functional limitations due to an inactive lifestyle might be reversed. Indeed, it has been suggested that physically active lifestyles may contribute to improving or maintaining health and wellness” (Fletcher, Gulanick, & Braun, 2005). The purpose of this study was to investigate the effects of two different physical activity programs on individuals aged 65 and older. The variables that were examined were functional skills (activities of daily living), balance skills, and overall upper extremity function. This study looked at two forms of physical activity to determine their individual effects on functional skills, balance, and overall upper extremity function in this population. The two physical activity interventions were the Nintendo Wii gaming system and a videotaped exercise routine.

Existence of Oscillatory Solutions of Singular Nonlinear Differential Equations
Irena Rach nková,Luká Rach nek,Jan Tome ek
Abstract and Applied Analysis , 2011, DOI: 10.1155/2011/408525
Abstract: Asymptotic properties of solutions of the singular differential equation (()())=()(()) are described. Here, f is Lipschitz continuous on ℝ and has at least two zeros 0 and >0. The function p is continuous on [0, ∞) and has a positive continuous derivative on (0, ∞) and (0)=0. Further conditions for f and p under which the equation has oscillatory solutions converging to 0 are given.
Nonmonotone impulse effects in second-order periodic boundary value problems
Irena Rach nková,Milan Tvrdy
Abstract and Applied Analysis , 2004, DOI: 10.1155/s1085337504306299
Abstract: We deal with the nonlinear impulsive periodic boundary valueproblem u″=f(t,u,u′), u(ti
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