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Search Results: 1 - 10 of 3754 matches for " Louise Hughes "
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Three-Dimensional Structure of the Trypanosome Flagellum Suggests that the Paraflagellar Rod Functions as a Biomechanical Spring
Louise C. Hughes, Katherine S. Ralston, Kent L. Hill, Z. Hong Zhou
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0025700
Abstract: Flagellum motility is critical for normal human development and for transmission of pathogenic protozoa that cause tremendous human suffering worldwide. Biophysical principles underlying motility of eukaryotic flagella are conserved from protists to vertebrates. However, individual cells exhibit diverse waveforms that depend on cell-specific elaborations on basic flagellum architecture. Trypanosoma brucei is a uniflagellated protozoan parasite that causes African sleeping sickness. The T. brucei flagellum is comprised of a 9+2 axoneme and an extra-axonemal paraflagellar rod (PFR), but the three-dimensional (3D) arrangement of the underlying structural units is poorly defined. Here, we use dual-axis electron tomography to determine the 3D architecture of the T. brucei flagellum. We define the T. brucei axonemal repeating unit. We observe direct connections between the PFR and axonemal dyneins, suggesting a mechanism by which mechanochemical signals may be transmitted from the PFR to axonemal dyneins. We find that the PFR itself is comprised of overlapping laths organized into distinct zones that are connected through twisting elements at the zonal interfaces. The overall structure has an underlying 57nm repeating unit. Biomechanical properties inferred from PFR structure lead us to propose that the PFR functions as a biomechanical spring that may store and transmit energy derived from axonemal beating. These findings provide insight into the structural foundations that underlie the distinctive flagellar waveform that is a hallmark of T. brucei cell motility.
Intrinsic genetic characteristics determine tumor-modifying capacity of fibroblasts: matrix metalloproteinase-3 5A/5A genotype enhances breast cancer cell invasion
Deborah L Holliday, Simon Hughes, Jacqueline A Shaw, Rosemary A Walker, J Louise Jones
Breast Cancer Research , 2007, DOI: 10.1186/bcr1775
Abstract: Primary breast fibroblasts were isolated from patients with (n = 13) or without (n = 19) breast cancer, and their ability to promote breast cancer cell invasion was measured in in vitro invasion assays. Fibroblast invasion-promoting capacity (IPC) was analyzed in relation to donor type (tumor or non-tumor patient), MMP-1, MMP-3, and MMP-9 SNP genotype and MMP activity using independent samples t test and analysis of variance. All statistical tests were two-sided.Tumor-derived fibroblasts promoted higher levels of invasion than normal fibroblasts (p = 0.041). When IPC was related to genotype, higher levels of IPC were generated by tumor fibroblasts with the high-expressing MMP-3 5A/5A genotype compared with the 5A/6A and 6A/6A genotypes (p = 0.05 and 0.07, respectively), and this was associated with enhanced MMP-3 release. The functional importance of MMP-3 was demonstrated by enhanced invasion in the presence of recombinant MMP-3, whereas reduction occurred in the presence of a specific MMP-3 inhibitor. An inverse relationship was demonstrated between fibroblast IPC and the high-expressing MMP-1 genotype (p = 0.031), but no relationship was seen with MMP-9 SNP status. In contrast, normal fibroblasts showed no variation in IPC in relation to MMP genotype, with MMP-3 5A/5A fibroblasts exhibiting significantly lower levels of IPC than their tumor-derived counterparts (p = 0.04).This study has shown that tumor-derived fibroblasts exhibit higher levels of IPC than normal fibroblasts and that the MMP-3 5A/5A genotype contributes to this through enhanced MMP-3 release. Despite a high-expressing genotype, normal fibroblasts do not exhibit higher IPC or enhanced MMP release. This suggests that more complex changes occur in tumor-derived fibroblasts, enabling full expression of the MMP SNP genotype and these possibly are epigenetic in nature. The results do suggest that, in women with breast cancer, a high-expressing MMP-3 genotype may promote tumor progression more effective
A microarray analysis of gene expression in the free-living stages of the parasitic nematode Strongyloides ratti
Fiona J Thompson, Gary LA Barker, Louise Hughes, Clare P Wilkes, Jane Coghill, Mark E Viney
BMC Genomics , 2006, DOI: 10.1186/1471-2164-7-157
Abstract: We have constructed an S. ratti cDNA microarray and used it to interrogate changes in gene expression during the free-living phase of the S. ratti life-cycle. We have found very extensive differences in gene expression between first-stage larvae (L1) passed in faeces and infective L3s preparing to infect hosts. In L1 stages there was comparatively greater expression of genes involved in growth. We have also compared gene expression in L2 stages destined to develop directly into infective L3s with those destined to develop indirectly into free-living adults. This revealed relatively small differences in gene expression. We find little evidence for the conservation of transcription profiles between S. ratti and S. stercoralis or C. elegans.This is the first multi-gene study of gene expression in S. ratti. This has shown that robust data can be generated, with consistent measures of expression within computationally determined clusters and contigs. We find inconsistencies between EST representation data and microarray hybridization data in the identification of genes with stage-specific expression and highly expressed genes. Many of the genes whose expression is significantly different between L1 and iL3s stages are unknown beyond alignments to predicted genes. This highlights the forthcoming challenge in actually determining the role of these genes in the life of S. ratti.Parasitic nematodes have complex life-cycles that are affected and controlled by factors both within and outwith their hosts. In the genus Strongyloides, the life-cycle, unusually, includes both an obligate female-only parasitic generation and a facultative dioecious adult free-living generation. In recent years there has been an increasingly detailed understanding of the factors that affect the development of the free-living phase of this life-cycle, particularly for the parasites of rats, S. ratti [1].S. ratti parasitic females lie embedded in the mucosa of the small intestine of their host. These
Passion for Beauty: A Model for Learning  [PDF]
Conrad Hughes
Creative Education (CE) , 2012, DOI: 10.4236/ce.2012.33053
Abstract: This essay investigates the idea that effective teaching entails a passion for the beauty of the subject matter being taught. The first part gives a summative overview of the last 72 years of constructivism with references to educational research and discussion on content, cognition and attitudes. This overview is set against the problem of increasing pressure on students and teachers in an age where university places are difficult to secure and students are not always motivated. The second part of the essay investigates the issue of student motivation. Forced learning will be discussed, the problems of trying to cater for student motivation through pedagogy and curriculum, and finally the idea of the muse, arguing that the most effective learning must involve some degree of passion for the subject from the teacher that the student integrates and appropriates. The conclusion of the essay considers passion for beauty as the core element of good learning and how this should be valorized openly and not seen as opposing constructivist pedagogy.
Patient preferences for future care - how can Advance Care Planning become embedded into dementia care: a study protocol
Louise Robinson, Claire Bamford, Fiona Beyer, Alexa Clark, Claire Dickinson, Charlotte Emmet, Catherine Exley, Julian Hughes, Lesley Robson, Nikki Rousseau
BMC Geriatrics , 2010, DOI: 10.1186/1471-2318-10-2
Abstract: The four phase project comprises a systematic review (Phase 1) and a series of qualitative studies (Phases 2 and 3), with data collection via focus groups and individual interviews with relevant stakeholders including people with dementia and their carers, health and social care professionals and representatives from voluntary organisations and the legal profession. The conduct of the systematic review will follow current best practice guidance. In phases 2 and 3, focus groups will be employed to seek the perspectives of the professionals; individual interviews will be carried out with people with dementia and their carers. Data from Phases 1, 2 and 3 will be synthesised in a series of team workshops to develop draft guidance and educational tools for implementing ACP in practice (Phase 4).In the UK, there is little published research on the effectiveness of ACP, despite its introduction into policy. This study was designed to explore in greater depth how ACP can best be carried out in routine practice. It affords the opportunity to develop both a theoretical and practical understanding of an area which both patients and professionals may find emotionally challenging. Importantly the study will also develop practical tools, which are grounded in practice, for all relevant stakeholders to enable the facilitation of timely and sensitive ACP discussions.Life expectancy is increasing by two years every decade. Currently older people represent the fastest growing sector of our population, with those over 60 years of age comprising one fifth of the population. The largest population increase will be seen in the oldest old i.e. people over 85 years. An ageing population will undoubtedly lead to an increased incidence of long term conditions, especially age-related illness such as osteoarthritis and dementia [1].In the United Kingdom, improving the health and social care of our ageing population is one of the government's strategic priority areas [2,3]. However there is cle
Genetics of a sex-linked recessive red eye color mutant of the tarnished plant bug, Lygus lineolaris  [PDF]
Margaret Louise Allen
Open Journal of Animal Sciences (OJAS) , 2013, DOI: 10.4236/ojas.2013.32A001
Abstract: An inbred colony of the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) (Miridae: Hemiptera), was observed to contain specimens with abnormal traits including red eyes, deformed antennae, and deformed legs. These specimens were isolated and back crossed to create stable phenotypic strains. The only successful strain established was a red eyed strain named Cardinal. The trait was more prevalent and stable in males, suggesting that it could be sex linked. To test the hypothesis that the trait was based on a recessive sex linked allele, classical genetic crosses were performed. The hypothesis was confirmed, and the eye color phenotype was measured and characterized using color analysis software. The trait is similar to other red eyed phenotypes described in this species, but is clearly based on a different mutation since it is sex linked rather than autosomal. The results of crossing experiments also suggest that inbreeding in this species results in substantial fitness cost to laboratory insects.
Genetics of a sex-linked recessive red eye color mutant of the tarnished plant bug, Lygus lineolaris  [PDF]
Margaret Louise Allen
Open Journal of Animal Sciences (OJAS) , 2013, DOI: 10.4236/ojas.2013.32A001
Abstract:

An inbred colony of the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) (Miridae: Hemiptera), was observed to contain specimens with abnormal traits including red eyes, deformed antennae, and deformed legs. These specimens were isolated and back crossed to create stable phenotypic strains. The only successful strain established was a red eyed strain named Cardinal. The trait was more prevalent and stable in males, suggesting that it could be sex linked. To test the hypothesis that the trait was based on a recessive sex linked allele, classical genetic crosses were performed. The hypothesis was confirmed, and the eye color phenotype was measured and characterized using color analysis software. The trait is similar to other red eyed phenotypes described in this species, but is clearly based on a different mutation since it is sex linked rather than autosomal. The results of crossing experiments also suggest that inbreeding in this species results in substantial fitness cost to laboratory insects.

A Combinatorial Analysis of Tree-Like Sentences  [PDF]
Gilbert Labelle, Louise Laforest
Open Journal of Discrete Mathematics (OJDM) , 2015, DOI: 10.4236/ojdm.2015.53004
Abstract: A sentence over a finite alphabet A, is a finite sequence of non-empty words over A. More generally, we define a graphical sentence over A by attaching a non-empty word over A to each arrow and each loop of a connected directed graph (digraph, for short). Each word is written according to the direction of its corresponding arrow or loop. Graphical sentences can be used to encode sets of sentences in a compact way: the readable sentences of a graphical sentence being the sentences corresponding to directed paths in the digraph. We apply combinatorial equations on enriched trees and rooted trees, in the context of combinatorial species and Pólya theories, to analyze parameters in classes of tree-like sentences. These are graphical sentences constructed on tree-like digraphs.
Gold: A Unique Pigmentation Defective Laboratory Strain of the Lady Beetle  [PDF]
Margaret Louise Allen
Advances in Entomology (AE) , 2016, DOI: 10.4236/ae.2016.41002
Abstract: A laboratory colony of Coleomegilla maculata (De Geer) was selected for a novel phenotypic color trait. The phenotype was paler in color than the wild type, although not as pale as a previously described mutant strain, yellow (ye), and retained dark pigmentation in the eyes. This selected strain was named gold. Mendelian breeding experiments indicate a recessive biallelic inheritance. The strain has decreased fitness characteristics based on measurements of egg production and pupa size.
Air-Ground Temperature Coupling: Analysis by Means of Thermal Orbits  [PDF]
Vladimir Cermak, Louise Bodri
Atmospheric and Climate Sciences (ACS) , 2016, DOI: 10.4236/acs.2016.61009
Abstract: Long-term measurements of air, near-surface (soil) and ground temperatures that were collected between 1994 and 2013 at the drill site of the Geothermal Climate Change Observatory (Prague) were analyzed to understand the relationship between these variables and to reveal the mechanisms of heat transport at the land-atmosphere boundary layer. The 2D Thermal Orbit (TO) method was applied to detect regularities that were hidden in noisy and highly variable temperature time series. The results showed that the temperatures at shallow depths were affected by surface air temperature (SAT) variations on seasonal and annual time scales and could be regarded as an accurate proxy for low frequency temperature variations at the Earth’s surface. Only low-frequency/ high-amplitude surface temperature variations penetrate into the subsurface because of strong damping and the filtering effect of the ground surface. The borehole temperatures have good potential to capture temperature variations (periodicities) over long time scales that cannot be detected in the SAT series themselves because of the interference of higher frequency noise. The TO technique is a useful and powerful tool to quickly obtain diagnostics of the presence of long periodicities in borehole temperature time series.
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