Search Results - (Author, Cooperation:E. Maher)

2012-06-23

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Adaptation, Physiological ; Air Microbiology ; Amino Acid Substitution ; Animals ; Birds ; *Evolution, Molecular ; Genetic Fitness ; Glycosylation ; Hemagglutinin Glycoproteins, Influenza Virus/*genetics/metabolism ; High-Throughput Nucleotide Sequencing ; Humans ; Influenza A Virus, H5N1 Subtype/*genetics/*pathogenicity ; Influenza in Birds/virology ; Influenza, Human/immunology/transmission/*virology ; Mammals ; Models, Biological ; Mutation ; Orthomyxoviridae Infections/transmission/*virology ; Probability ; RNA Replicase/*genetics ; Receptors, Virus/metabolism ; Respiratory System/*virology ; Selection, Genetic ; Sialic Acids/metabolism ; Viral Proteins/*genetics

2018-11-27

Institute of Physics Publishing (IOP)

1748-0221

Physics

2018-05-26

BMJ Publishing Group

0022-2593

1468-6244

Medicine

Open access, Molecular genetics

2018-01-25

BMJ Publishing Group

0022-2593

1468-6244

Medicine

Genetic screening / counselling

2018-06-26

BMJ Publishing Group

0022-2593

1468-6244

Medicine

1365-2214

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Psychology

Background Although there is increasing recognition that quality of life (QOL) and health-related quality of life (HRQOL) are important outcome variables in clinical trials for children with cerebral palsy, there are substantial limitations in existing measures of QOL. This study identify themes of QOL for children with cerebral palsy and their parents to guide the development of a new condition-specific QOL scale.Methods A qualitative study of parent and child views on QOL composition was conducted, using a grounded theory framework. Families participated in semistructured interviews on QOL until thematic saturation was reached (n = 28 families).Results Overall, 13 themes emerged from the interviews: physical health, body pain and discomfort, daily living tasks, participation in regular physical and social activities, emotional well-being and self-esteem, interaction with the community, communication, family health, supportive physical environment, future QOL, provision of, and access to services, financial stability, and social well-being.Conclusions Research with parents and children with cerebral palsy, representative of severity across the disease spectrum and socio-economic status, reinforced and expanded on the traditional themes that have underpinned QOL measurement development. This has implications not only for the development of a new QOL scale for children with cerebral palsy, but also for clinical interventions and community care management.

Electronic Resource

1399-3054

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Growth and gravitropism have been studied in three mutant strains of Arabidopsis thaliana L, that are resistant to auxin-herbicide. Two of the mutations are allelic and recessive (aux-1 and aux-2) and are unlinked to a dominant mutation, Dwf, which confers a very high level of auxin-resistance and is apparently lethal when homozygous. The aux-1 and Dwf strains have altered response to gravity whereas aux-2 appears to be gravitropically normal.After 96 h in the normal, vertical position only minor differences in elongation were observed between roots of wild-type, aux-1 and aux-2, but the hypocotyls of aux-1 were significantly retarded compared with the gravitropically normal aux-2 and wild-type. In the progeny of selfed Dwf plants, where both normal (dwf) and agravitropic (Dwf) seedlings are present, the Dwf seedlings had much longer roots and shorter hypocotyls than dwf+. During 22 h of continuous stimulation the optimum angle for gravitropism in wild-type roots and hypocotyls was 135° (i.e. the organ points obliquely upwards), with decreasing responses in the order 90° and 45°. The agravitropic nature of the roots of aux-1 was confirmed as no significant response was obtained at any of the stimulation angles. In marked contrast, the negative gravitropic response of aux-1 hypocotyls was greater than the wild-type response in terms of the final angle attained at 22 h, but between 6 and 22 h the elongation rate was lower in aux-1. After varying stimulation periods in the horizontal position, the curvature which had developed, decreased rapidly and almost disappeared during ensuing rotation on clinostats (2 and 4 rpm). Rotation on the clinostats had no effect on the agravitropic behaviour of aux-1.

Electronic Resource

0014-5793

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

1399-3054

Blackwell Publishing Journal Backfiles 1879-2005

Biology

The root anatomy and ultrastructure of the agravitropic Arabidopsis thaliana L. mutants Dwf and aux-1 were compared with the gravitropic mutant aux-2 and the wild type (WT) in an attempt to find an explanation for the lack of response to gravity. No differences were found in the organization of the root cap. The central part of the cap (columella) contains 5 storeys of developing, functioning and degenerating statocytes. Their ultrastructure is very similar in all four types of plant. Particular attention was paid to the distribution of rough endoplasmie reticulum (ER). Both in the WT and the mutants the ER is concentrated in the distal part at the “floor” of the cell.Light micrographs were used to compare the sedimentation rates of movable cell structures in normal and agravitropic root statocytes. A longitudinal movement of amyloplasts and nuclei was observed when the roots were inverted. In WT and aux-2 the rates were on average 6.3 μm h−1 (amyloplasts) and 2.1 μm h−1 (nucleus). In aux-1 the sedimentation rates were significantly lower: 2.4 and 0.6 μm h−1, respectively. Based on magnified electron micrographs of normal and inverted statocytes a morphometrical analysis of the distribution and redistribution of amyloplasts, nuclei, mitochondria, vacuoles and ER was made. The only significant difference was found in the redistribution of amyloplasts between aux-1 and the gravitropical normal types.

Electronic Resource

0168-9452

Arabidopsis ; agravitropic mutants ; auxin sensitivity ; gravitropism

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Electronic Resource

1432-1238

Springer Online Journal Archives 1860-2000

Medicine

Electronic Resource

1432-1203

Springer Online Journal Archives 1860-2000

Biology

Medicine

Abstract As part of our effort to isolate and characterise the von Hippel-Lindau (VHL) disease gene, we constructed a physical map of chromosome 3p25-26 by fluorescence in situ hybridisation (FISH) studies on a panel of cytogenetic rearrangements involving this region. Biotinylated cosmid and lambda probes were hybridised to metaphase chromosome spreads and positioned with respect to each cytogenetic breakpoint. These studies unequivocally established the order of five loci linked to the VHL disease gene: cen-(RAF1,312)-D3S732-D3S1250-D3S601-D3S18-pter and determined the position of three other probes within this map. These results ordered RAF1 and D3S732 for the first time, confirmed the localisation of D3S1250 between RAF1 and D3S601 and determined the position of D3S651 with respect to other chromosome 3p25-p26 loci. The establishment of an ordered set of cytogenetic aberrations will enable the rapid assignment of polymorphic and nonpolymorphic cloned sequences within the chromosome region 3p25-p26.

Electronic Resource

1432-2048

Arabidopsis ; Cucumis ; Gravity and hypocotyl curvature ; Hetianthus ; Hypocotyl hook formation and opening ; Lepidium

Springer Online Journal Archives 1860-2000

Biology

Abstract Photographic observations on germinating seedlings of Lepidium sativum L., Cucumis sativus L., and Helianthus annuus L. showed that the hypocotyl hook is not present in the seed but forms during the early stages of growth. Evidence that gravity plays a major role in inducing curvature of the hypocotyl, and in maintaining the hook once it has been formed, was obtained from clinostat experiments, from the use of morphactin to remove geotropic sensitivity and from inversion of seedlings to change the direction of the geostimulus. In L. sativum and H. annuus gravity perception seemed to be the only mechanism responsible for hook formation. In C. sativus hook formation was additionally aided by the mode of emergence of the cotyledons from the seed coat but gravity played an indirect role in regulating such emergence. Further evidence that hook formation is linked to a georesponse was derived from a comparison of hypocotyl development in wild-type Arabidopsis thaliana seedlings with that of an ageotropic mutant, hook formation being found to occur only in the wild type. Hook formation and maintenance is discussed in terms of contrasting geosensitivity between the apical and basal ends of the hypocotyl and it is suggested that light-induced hook opening is a reversal to a condition of uniformly negative georesponse throughout the hypocotyl.

Electronic Resource

1573-4927

Arabidopsis thaliana ; auxin ; gravity ; auxin-resistant mutants

Springer Online Journal Archives 1860-2000

Biology

Chemistry and Pharmacology

Abstract Auxin-resistant mutants of Arabidopsis have been induced and isolated by screening for survivors on a medium containing the herbicide 2,4-D. Thirty independently arisen mutants have been isolated in this way and one of them, P 83, has been investigated in detail. When wild type and P 83 are compared in concentration/response curves, where the response is the inhibition of root growth, the ED50 values of the auxins, 2,4-D and IAA, are 14-fold higher for the mutant. The mutant also responds differently to gravity: its roots do not show positive geotropism, but tend to grow with a clockwise curvature on agar surfaces. The seedling roots of the mutant also grow more rapidly than those of the wild type in the absence of 2,4-D, following faster germination. The F1 between P 83 and wild type is similar to the latter, but has a slightly increased resistance to 2,4-D. Results obtained from the F2, F3 and backcross generations suggest monofactorial inheritance. Most of the other 29 mutants have the P 83 phenotype, but at least five are different. Four have lower levels of resistance to 2,4-D and P 83, and their roots appear to respond normally to gravity. One mutant has an abnormal georesponse and a much higher level of resistance to 2,4-D than P 83.

Electronic Resource

1573-4927

Springer Online Journal Archives 1860-2000

Biology

Chemistry and Pharmacology

Abstract Evidence has been sought on the possible existence of multiple forms of the enzyme controlled by the Li locus in white clover. During purification of enzyme from LiLi plants, there was no separation of activities against the β-glucosides, p-nitrophenyl β-d-glucoside, salicin, and linamarin-lotaustralin, and the β-galactoside, p-nitrophenyl β-d-galactoside. In addition, tests on mixtures of these four substrates provided no evidence for the existence of more than one enzyme. Immunological tests have shown that plants homozygous for the recessive li allele do not contain an enzymatically inactive protein, antigenically related to the normal enzyme. This suggests that li alleles either specify a low-activity immunologically altered protein or control the synthesis of very low levels of normal enzyme.

Electronic Resource

1573-4927

Springer Online Journal Archives 1860-2000

Biology

Chemistry and Pharmacology

Abstract Various reagents which prevent enzyme inhibition by phenolic compounds were tested in attempts to improve the medium used to extract the Li-controlled enzyme activities from white clover leaves. The addition of 50 mm diethyldithiocarbamate to the extraction medium gave a fivefold increase in the enzyme activity of LiLi white clover extracts against p-nitrophenyl β-d-glucoside, linamarin-lotaustralin, and p-nitrophenyl β-d-galactoside. These three substrates were used in tests on the effect of genotype on enzyme activity. An absence of dominance at the Li locus was demonstrated, with a dosage effect of Li alleles on enzyme activity. A new Li allele was identified in the Lili clone, C11, which had low levels of enzyme activity. In crosses with two lili clones, Li(C11)li progeny were produced with activity levels similar to those of the C11 parent. Inhibition and heat-inactivation tests suggest that the lili clone, D4, produces an altered form of β-glucosidase which may also be present in LiLi plants. The nature of the Li locus is discussed.

Electronic Resource

1617-4623

Agravitropic mutants ; Arabidopsis ; Auxin ; Auxin sensitivity ; Gravitropism

Springer Online Journal Archives 1860-2000

Biology

Summary Mutants of Arabidopsis thaliana (L) Heyhn were induced by soaking seed in the mutagen, ethyl methanesulfonate (EMS). The progeny of the mutagen-treated generation were screened for abnormal root gravitropism and three mutants were isolated: agr-1, agr-2 and agr-3. Genetic analysis showed these to be alleles of one locus distinct from that of two previously described allelic mutations, aux-1 and aux-2. The agr phenotypes are recessive and analysis of agr-1 suggests monofactorial inheritance. The roots of agr-1 appear to be totally agravitropic while those of agr-2 and agr-3 show reduced responses to gravity. agr-3 also shows negative root gravitropism as a variable trait. The roots of agr-1 and agr-2 were found to have normal responses to the inhibitory effects of 2,4-dichlorophenoxyacetic acid (2,4-D) but those of agr-3 were significantly more sensitive. No other phenotypic abnormalities were detected.

Electronic Resource

1573-5087

agravitropism ; auxin-resistance ; dwarfism

Springer Online Journal Archives 1860-2000

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Abstract Two auxin-resistant mutants of Arabidopsis thaliana L. have been characterized physiologically: aux-2 is a recessive mutation and is unlinked to a dominant mutation, Dwf, which is apparently lethal when homozygous. The progeny of selfed Dwf plants segregate into Dwf (agravitropic) and dwf + (normal) phenotypes. aux-2 phenotype was indistinguishable from the wild-type on criteria other than resistance to exogenous auxins: 3-fold to 2,4-D and 2-fold to IAA. On the other hand, Dwf plants had a typical dwarf phenotype with single unbranched roots which lacked hairs. Compared to the wild-type, Dwf seedling roots were highly resistant to exogenous auxins: 2000-fold to 2,4-D and 360-fold to IAA. Both aux-2 and Dwf were normal in their response to exogenous ABA. The dwarf phenotype was insensitive to gibberellins but root hair formation was restored by application of auxins. The results indicate that altered auxin phsysiology can lead to agravitropism and dwarfism.

Electronic Resource