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1.
Phys Rev Lett ; 128(11): 112501, 2022 Mar 18.
Article in English | MEDLINE | ID: mdl-35363028

ABSTRACT

Using the fusion-evaporation reaction ^{96}Ru(^{58}Ni,p4n)^{149}Lu and the MARA vacuum-mode recoil separator, a new proton-emitting isotope ^{149}Lu has been identified. The measured decay Q value of 1920(20) keV is the highest measured for a ground-state proton decay, and it naturally leads to the shortest directly measured half-life of 450_{-100}^{+170} ns for a ground-state proton emitter. The decay rate is consistent with l_{p}=5 emission, suggesting a dominant πh_{11/2} component for the wave function of the proton-emitting state. Through nonadiabatic quasiparticle calculations it was concluded that ^{149}Lu is the most oblate deformed proton emitter observed to date.

2.
Phys Rev Lett ; 126(18): 182501, 2021 May 07.
Article in English | MEDLINE | ID: mdl-34018761

ABSTRACT

In two recent papers by Pore et al. and Khuyagbaatar et al., discovery of the new isotope ^{244}Md was reported. The decay data, however, are conflicting. While Pore et al. report two isomeric states decaying by α emission with E_{α}(1)=8.66(2) MeV, T_{1/2}(1)=0.4_{-0.1}^{+0.4} s and E_{α}(2)=8.31(2) MeV, T_{1/2}(2)≈6 s, Khuyagbaatar et al. [Phys. Rev. Lett. 125, 142504 (2020).PRLTAO0031-900710.1103/PhysRevLett.125.142504] report only a single transition with a broad energy distribution of E_{α}=(8.73-8.86) MeV and T_{1/2}=0.30_{-0.09}^{+0.19} s. The data published in Pore et al. are very similar to those published for ^{245m}Md [E_{α}=8.64(2), 8.68(2) MeV, T_{1/2}=0.35_{-0.16}^{+0.23} s [V. Ninov, F. P. Heßberger, S. Hofmann, H. Folger, G. Münzenberg, P. Armbruster, A. V. Yeremin, A. G. Popeko, M. Leino, and S. Saro, Z. Phys. A 356, 11 (1996).ZPAHEX0939-792210.1007/s002180050141] ]. Therefore, we compare the data presented for ^{244}Md in Pore et al. with those reported for ^{245}Md in Ninov et al. and also in Khuyagbaatar et al. We conclude that the data presented in Pore et al. shall be attributed to ^{245}Md with small contributions (one event each) from ^{245}Fm and probably ^{246}Md.

3.
Allergol. immunopatol ; 44(1): 9-17, ene.-feb. 2016. graf, ilus
Article in English | IBECS | ID: ibc-147478

ABSTRACT

BACKGROUND: Allergen-specific immunotherapy balances the Th2-biased immunity towards Th1 and Treg responses. Adjuvants are used in allergen preparations to intensify the immune responses. The increased prevalence of allergies in developed societies has been associated with decreased microbial load during childhood. This has initiated a search for microbial structures to be used as adjuvants. Our study has shown that a synthetic triacedimannose (TADM) may suppress the Th2-type allergic inflammatory response. The aim of this study was to compare the properties of TADM with capacities of other adjuvants, CpG ODN and MPL, to modulate cytokine production in PBMC and regulate sensitisation in an OVA-sensitised mouse asthma model. METHODS: The effects of TADM were studied in vitro on birch stimulated PBMC cultures of birch allergic rhinitis patients with other known adjuvants. Cytokines in supernatants were measured by Luminex. Effects of TADM were analysed in vivo in a mouse model of OVA-induced allergic asthma by analysing BAL, cytokine mRNA and serum antibodies. RESULTS: TADM was the only adjuvant that significantly suppressed the production of all birch induced Th2-type cytokines. In a murine model, TADM significantly suppressed the specific IgE production and enhanced IFN-γ production. CONCLUSIONS: TADM suppresses the birch allergen induced Th2-type cytokine responses in allergic subjects more efficiently than the two other adjuvants, MPL and CpG ODN. TADM is immunomodulatory also in vivo and decreases the IgE levels and increases the IFN-γ responses in a murine model. These results suggest that TADM may be a promising candidate for novel adjuvants in immunotherapy


No disponible


Subject(s)
Animals , Male , Female , Mice , Adjuvants, Immunologic , Adjuvants, Immunologic/therapeutic use , Immunotherapy/instrumentation , Immunotherapy/methods , Immunotherapy/veterinary , Disease Models, Animal , Models, Animal , Immunotherapy/standards , Immunotherapy , Asthma/immunology , Asthma/veterinary , In Vitro Techniques/instrumentation , In Vitro Techniques/veterinary
4.
Scand J Rheumatol ; 45(4): 294-8, 2016 Jul.
Article in English | MEDLINE | ID: mdl-26681432

ABSTRACT

OBJECTIVES: The aims of this study were to determine the within-patient variation in the duration of morning stiffness (MS) over 1 year and the corresponding monetary equivalents assigned to its changes using the willingness-to-pay (WTP) methodology. METHOD: A sample of 100 patients with rheumatoid arthritis (RA) was drawn from the register of the Hospital District of Southwest Finland. Subjects were interviewed by telephone on recruitment and 1 year later, using the same structured questionnaire. The subjects were asked to estimate in minutes the typical duration of their MS during the previous week. Sociodemographic background data and subjects' WTP for a 25, 50, 75, and 100% reduction in MS duration were requested, and years with RA diagnosis and serological data were obtained from hospital records. RESULTS: After 1 year, there was a reduction in average MS duration from 44.7 min to 39.0 min (ns); duration was reduced in 35% of patients, unchanged in 35%, and prolonged in 30%. Changes in MS duration were reflected by within-patient variation in WTP estimates. In linear regression models, change in duration of MS significantly (p < 0.03) explained the variation in change of WTP for symptom reduction. CONCLUSIONS: WTP methodology produces consistent monetary values to assess the relative values patients with RA place on reduction in duration of MS.


Subject(s)
Arthritis, Rheumatoid/physiopathology , Aged , Arthritis, Rheumatoid/economics , Circadian Rhythm , Cost-Benefit Analysis , Female , Finland , Humans , Linear Models , Male , Middle Aged , Surveys and Questionnaires
5.
Allergol Immunopathol (Madr) ; 44(1): 9-17, 2016.
Article in English | MEDLINE | ID: mdl-26395525

ABSTRACT

BACKGROUND: Allergen-specific immunotherapy balances the Th2-biased immunity towards Th1 and Treg responses. Adjuvants are used in allergen preparations to intensify the immune responses. The increased prevalence of allergies in developed societies has been associated with decreased microbial load during childhood. This has initiated a search for microbial structures to be used as adjuvants. Our study has shown that a synthetic triacedimannose (TADM) may suppress the Th2-type allergic inflammatory response. The aim of this study was to compare the properties of TADM with capacities of other adjuvants, CpG ODN and MPL, to modulate cytokine production in PBMC and regulate sensitisation in an OVA-sensitised mouse asthma model. METHODS: The effects of TADM were studied in vitro on birch stimulated PBMC cultures of birch allergic rhinitis patients with other known adjuvants. Cytokines in supernatants were measured by Luminex. Effects of TADM were analysed in vivo in a mouse model of OVA-induced allergic asthma by analysing BAL, cytokine mRNA and serum antibodies. RESULTS: TADM was the only adjuvant that significantly suppressed the production of all birch induced Th2-type cytokines. In a murine model, TADM significantly suppressed the specific IgE production and enhanced IFN-γ production. CONCLUSIONS: TADM suppresses the birch allergen induced Th2-type cytokine responses in allergic subjects more efficiently than the two other adjuvants, MPL and CpG ODN. TADM is immunomodulatory also in vivo and decreases the IgE levels and increases the IFN-γ responses in a murine model. These results suggest that TADM may be a promising candidate for novel adjuvants in immunotherapy.


Subject(s)
Adjuvants, Immunologic/administration & dosage , Asthma/therapy , Conjunctivitis/therapy , Desensitization, Immunologic , Mannosides/administration & dosage , Rhinitis, Allergic/therapy , Th2 Cells/immunology , Adult , Allergens/administration & dosage , Allergens/immunology , Animals , Asthma/immunology , Betula/immunology , Cells, Cultured , Conjunctivitis/immunology , Cytokines/metabolism , Disease Models, Animal , Female , Humans , Lipid A/administration & dosage , Lipid A/analogs & derivatives , Male , Mice , Mice, Inbred BALB C , Middle Aged , Oligodeoxyribonucleotides/administration & dosage , Ovalbumin/immunology , Rhinitis, Allergic/immunology
6.
Heredity (Edinb) ; 114(2): 195-206, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25227257

ABSTRACT

The geographic distribution of genetic diversity can reveal the evolutionary history of a species. For crop plants, phylogeographic patterns also indicate how seed has been exchanged and spread in agrarian communities. Such patterns are, however, easily blurred by the intense seed trade, plant improvement and even genebank conservation during the twentieth century, and discerning fine-scale phylogeographic patterns is thus particularly challenging. Using historical crop specimens, these problems are circumvented and we show here how high-throughput genotyping of historical nineteenth century crop specimens can reveal detailed geographic population structure. Thirty-one historical and nine extant accessions of North European landrace barley (Hordeum vulgare L.), in total 231 individuals, were genotyped on a 384 single nucleotide polymorphism assay. The historical material shows constant high levels of within-accession diversity, whereas the extant accessions show more varying levels of diversity and a higher degree of total genotype sharing. Structure, discriminant analysis of principal components and principal component analysis cluster the accessions in latitudinal groups across country borders in Finland, Norway and Sweden. FST statistics indicate strong differentiation between accessions from southern Fennoscandia and accessions from central or northern Fennoscandia, and less differentiation between central and northern accessions. These findings are discussed in the context of contrasting historical records on intense within-country south to north seed movement. Our results suggest that although seeds were traded long distances, long-term cultivation has instead been of locally available, possibly better adapted, genotypes.


Subject(s)
Agriculture , Genetics, Population , Hordeum/genetics , Polymorphism, Single Nucleotide , Biological Evolution , DNA, Plant/genetics , Finland , Genotype , Linkage Disequilibrium , Norway , Phylogeography , Principal Component Analysis , Sweden
7.
Dermatol Ther (Heidelb) ; 4(1): 115-24, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24865468

ABSTRACT

INTRODUCTION: Psoriasis results in expenses to patients from many cost sources. Psoriasis treatments may result in considerable time and traveling costs, yet many studies fail to account for these costs. The objective of this study was to evaluate the multidimensional economic burden of psoriasis to patients. METHODS: The study was based on 232 Finnish patients with psoriasis or psoriatic arthritis visiting a tertiary level dermatological clinic during a 1-year study period between October 1, 2009 and September 30, 2010. The data were based on a patient questionnaire, clinical data from the medical records and reimbursement data from the Finnish Social Insurance Institution. Item costs were based on true costs charged from the patients and all time cost estimates were based on the Human Capital Approach method. RESULTS: 199 patients with psoriasis and 33 with psoriatic arthritis were included in the study. Total costs were higher for patients receiving traditional systemic medications or phototherapy than those not receiving such treatment. Travel costs and travel time costs accounted for more than 60% of the costs of phototherapy. Skin care at home was time consuming and thus caused significant burden to patients. The majority of the visit costs arose from hospital visits and only a small proportion were attributed to visiting primary health care providers. CONCLUSION: Visit charges and other patient co-payments were estimated to play a minor role in the total cost of psoriasis incurred by patients, while travel costs and lost time comprised the majority of the costs, which should not be omitted in future studies regarding costs of treatments.

8.
Phys Rev Lett ; 112(9): 092501, 2014 Mar 07.
Article in English | MEDLINE | ID: mdl-24655248

ABSTRACT

A multiparticle spin-trap isomer has been discovered in the proton-unbound nucleus (73)(158)Ta85 . The isomer mainly decays by γ-ray emission with a half-life of 6.1(1) µs. Analysis of the γ-ray data shows that the isomer lies 2668 keV above the known 9+ state and has a spin 10ℏ higher and negative parity. This 19- isomer also has an 8644(11) keV, 1.4(2)% α-decay branch that populates the 9+ state in (154)Lu. No proton-decay branch from the isomer was identified, despite the isomer being unbound to proton emission by 3261(14) keV. This remarkable stability against proton emission is compared with theoretical predictions, and the implications for the extent of observable nuclides are considered.

9.
Heredity (Edinb) ; 110(4): 338-46, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23169556

ABSTRACT

Landrace crops are formed by local adaptation, genetic drift and gene flow through seed exchange. In reverse, the study of genetic structure between landrace populations can reveal the effects of these forces over time. We present here the analysis of genetic diversity in 40 Swedish field pea (Pisum sativum L.) populations, either available as historical seed samples from the late nineteenth century or as extant gene bank accessions assembled in the late twentieth century. The historical material shows constant high levels of within-population diversity, whereas the extant accessions show varying, and overall lower, levels of within-population diversity. Structure and principal component analysis cluster most accessions, both extant and historical, in groups after geographical origin. County-wise analyses of the accessions show that the genetic diversity of the historical accessions is largely overlapping. In contrast, most extant accessions show signs of genetic drift. They harbor a subset of the alleles found in the historical accessions and are more differentiated from each other. These results reflect how, historically present metapopulations have been preserved during the twentieth century, although as genetically isolated populations.


Subject(s)
Genetics, Population , Pisum sativum/genetics , Seeds/genetics , Selection, Genetic , Alleles , Breeding , Genetic Variation , Geography , Sweden
10.
Phys Rev Lett ; 109(1): 012501, 2012 Jul 06.
Article in English | MEDLINE | ID: mdl-23031099

ABSTRACT

The rotational band structure of the Z=104 nucleus (256)Rf has been observed up to a tentative spin of 20ℏ using state-of-the-art γ-ray spectroscopic techniques. This represents the first such measurement in a superheavy nucleus whose stability is entirely derived from the shell-correction energy. The observed rotational properties are compared to those of neighboring nuclei and it is shown that the kinematic and dynamic moments of inertia are sensitive to the underlying single-particle shell structure and the specific location of high-j orbitals. The moments of inertia therefore provide a sensitive test of shell structure and pairing in superheavy nuclei which is essential to ensure the validity of contemporary nuclear models in this mass region. The data obtained show that there is no deformed shell gap at Z=104, which is predicted in a number of current self-consistent mean-field models.

11.
Phys Rev Lett ; 102(21): 212501, 2009 May 29.
Article in English | MEDLINE | ID: mdl-19519098

ABSTRACT

The rotational band structure of 255Lr has been investigated using advanced in-beam gamma-ray spectroscopic techniques. To date, 255Lr is the heaviest nucleus to be studied in this manner. One rotational band has been unambiguously observed and strong evidence for a second rotational structure was found. The structures are tentatively assigned to be based on the 1/2-[521] and 7/2-[514] Nilsson states, consistent with assignments from recently obtained alpha decay data. The experimental rotational band dynamic moment of inertia is used to test self-consistent mean-field calculations using the Skyrme SLy4 interaction and a density-dependent pairing force.

12.
Occup Environ Med ; 65(12): 849-56, 2008 Dec.
Article in English | MEDLINE | ID: mdl-18417560

ABSTRACT

OBJECTIVES: To examine the efficacy of a participatory ergonomics intervention in preventing musculoskeletal disorders among kitchen workers. Participatory ergonomics is commonly recommended to reduce musculoskeletal disorders, but evidence for its effectiveness is sparse. METHODS: A cluster randomised controlled trial among the 504 workers of 119 kitchens in Finland was conducted during 2002-2005. Kitchens were randomised to an intervention (n = 59) and control (n = 60) group. The duration of the intervention that guided the workers to identify strenuous work tasks and to seek solutions for decreasing physical and mental workload, was 11 to 14 months. In total, 402 ergonomic changes were implemented. The main outcome measures were the occurrence of and trouble caused by musculoskeletal pain in seven anatomical sites, local fatigue after work, and sick leave due to musculoskeletal disorders. Individual level data were collected by a questionnaire at baseline and every 3 months during the intervention and 1-year follow-up period. All response rates exceeded 92%. RESULTS: No systematic differences in any outcome variable were found between the intervention and control groups during the intervention or during the 1-year follow-up. CONCLUSIONS: The intervention did not reduce perceived physical work load and no evidence was found for the efficacy of the intervention in preventing musculoskeletal disorders among kitchen workers. It may be that a more comprehensive redesign of work organisation and processes is needed, taking more account of workers' physical and mental resources.


Subject(s)
Cooking , Ergonomics/methods , Food Handling , Musculoskeletal Diseases/prevention & control , Occupational Diseases/prevention & control , Adult , Female , Humans , Male , Middle Aged , Musculoskeletal Diseases/etiology , Musculoskeletal Diseases/pathology , Occupational Diseases/etiology , Occupational Diseases/pathology , Pain/etiology , Pain/pathology , Pain/prevention & control , Pain Measurement/methods , Sick Leave/statistics & numerical data , Treatment Outcome , Workload , Young Adult
13.
Phys Rev Lett ; 99(2): 022501, 2007 Jul 13.
Article in English | MEDLINE | ID: mdl-17678215

ABSTRACT

Gamma-ray transitions have been identified for the first time in the extremely neutron-deficient (N=Z+2) nucleus (110)Xe, and the energies of the three lowest excited states in the ground-state band have been deduced. The results establish a breaking of the normal trend of increasing first excited 2(+) and 4(+) level energies as a function of the decreasing neutron number as the N=50 major shell gap is approached for the neutron-deficient Xe isotopes. This unusual feature is suggested to be an effect of enhanced collectivity, possibly arising from isoscalar n-p interactions becoming increasingly important close to the N=Z line.

14.
Phys Rev Lett ; 98(13): 132503, 2007 Mar 30.
Article in English | MEDLINE | ID: mdl-17501196

ABSTRACT

A rotational band has been unambiguously observed in an odd-proton transfermium nucleus for the first time. An in-beam gamma-ray spectroscopic study of 101/251Md has been performed using the gamma-ray array JUROGAM combined with the gas-filled separator RITU and the focal plane device GREAT. The experimental results, compared to Hartree-Fock-Bogolyubov calculations, lead to the interpretation that the rotational band is built on the [521]1/2(-) Nilsson state.

15.
Phys Rev Lett ; 97(6): 062501, 2006 Aug 11.
Article in English | MEDLINE | ID: mdl-17026165

ABSTRACT

Lifetimes of prolate intruder states in 186Pb and oblate intruder states in 194Po have been determined by employing, for the first time, the recoil-decay tagging technique in recoil distance Doppler-shift lifetime measurements. In addition, lifetime measurements of prolate states in 188Pb up to the 8+ state were carried out using the recoil-gating method. The B(E2) values have been deduced from which deformation parameters |beta2|=0.29(5) and |beta2|=0.17(3) for the prolate and the oblate bands, respectively, have been extracted. The results also shed new light on the mixing between different shapes.

16.
Nature ; 442(7105): 896-9, 2006 Aug 24.
Article in English | MEDLINE | ID: mdl-16929293

ABSTRACT

A long-standing prediction of nuclear models is the emergence of a region of long-lived, or even stable, superheavy elements beyond the actinides. These nuclei owe their enhanced stability to closed shells in the structure of both protons and neutrons. However, theoretical approaches to date do not yield consistent predictions of the precise limits of the 'island of stability'; experimental studies are therefore crucial. The bulk of experimental effort so far has been focused on the direct creation of superheavy elements in heavy ion fusion reactions, leading to the production of elements up to proton number Z = 118 (refs 4, 5). Recently, it has become possible to make detailed spectroscopic studies of nuclei beyond fermium (Z = 100), with the aim of understanding the underlying single-particle structure of superheavy elements. Here we report such a study of the nobelium isotope 254No, with 102 protons and 152 neutrons--the heaviest nucleus studied in this manner to date. We find three excited structures, two of which are isomeric (metastable). One of these structures is firmly assigned to a two-proton excitation. These states are highly significant as their location is sensitive to single-particle levels above the gap in shell energies predicted at Z = 114, and thus provide a microscopic benchmark for nuclear models of the superheavy elements.

17.
Heart ; 92(4): 474-80, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16159979

ABSTRACT

OBJECTIVE: To examine the association of childhood socioeconomic position (SEP) with adult cardiovascular risk factors, vascular structure, and vascular function in a contemporary population of young adults. DESIGN: Population based prospective cohort study with baseline assessment in 1980. SETTING: Finland. PARTICIPANTS: 856 men and 1066 women whose childhood SEP was determined by parental occupational status (manual, lower non-manual, upper non-manual) at age 3-18 years. MAIN OUTCOME MEASURES: Cardiovascular risk factors, carotid artery intima-media thickness, and brachial artery flow mediated vasodilatation, assessed at age 24-39 years. RESULTS: After adjustment for age and adult SEP, systolic pressure was 2.3 mm Hg higher (p = 0.0002), high density lipoprotein (HDL) cholesterol 0.03 mmol/l lower (p = 0.02), and insulin resistance score (homeostasis model assessment index) 0.12 units greater (p = 0.05) among men; and systolic pressure was 1.3 mm Hg higher (p = 0.02), diastolic pressure 1.1 mm Hg higher (p = 0.01), and height 1.1 cm lower (p < 0.0001) among women for each step down the childhood SEP hierarchy. Lower childhood SEP was associated with a 20% increase in the odds of having a waist circumference > 102 cm in men and > 88 cm in women (overall p = 0.05). Childhood SEP was not associated with intima-media thickness, flow mediated vasodilatation, the metabolic syndrome, low density lipoprotein cholesterol, triglycerides, body mass index, alcohol consumption, or smoking. CONCLUSIONS: Among adults under 40, low childhood SEP predicted higher blood pressure and central obesity and, among men, unfavourable HDL cholesterol and insulin resistance, independent of current SEP. No independent effects were found on adult vascular structure, vascular function, or health related behaviours at this life stage.


Subject(s)
Cardiovascular Diseases/etiology , Social Class , Adolescent , Adult , Anthropometry , Blood Pressure , Cardiovascular Diseases/epidemiology , Carotid Arteries/anatomy & histology , Child , Child, Preschool , Cohort Studies , Female , Finland/epidemiology , Humans , Male , Prospective Studies , Risk Factors , Tunica Intima/anatomy & histology
18.
Allergy ; 60(10): 1275-9, 2005 Oct.
Article in English | MEDLINE | ID: mdl-16134994

ABSTRACT

BACKGROUND: The characteristic feature of chronic rhinosinusitis with nasal polyposis (CRSwNP) is eosinophilic inflammation of the sinus mucosa; a type of inflammation also seen in asthmatic airways. Similar histopathologic findings of airway remodelling are present in both diseases. Remodelling is tightly controlled by matrix metalloproteinases (MMP). Increase of collagenase-2 (MMP-8) expression in the bronchial epithelial cells has been described in asthmatic patients, but it has not been studied in CRSwNP. METHODS: The concentrations and degree of activation of MMP-8 were analysed by immunofluorometric assay and Western blotting, respectively, in sinus mucus samples from CRSwNP patients and in nasal lavages from healthy controls in relation to inductive cytokines interleukin-8 (IL-8) and tumour necrosis factor-alpha (TNF-alpha). RESULTS: Significantly elevated levels of MMP-8 and IL-8 but not TNF-alpha were found in CRSwNP patients relative to controls. In particular, the activation of mesenchymal-type MMP-8 but not polymorphonuclear-type MMP-8 was associated with elevated IL-8 levels. CONCLUSIONS: The IL-8 and MMP-8 seemingly form an inductive cytokine-proteinase cascade in CRSwNP pathogenesis. Together they provide a target for novel therapies and a diagnostic tool for monitoring CRSwNP treatment.


Subject(s)
Interleukin-8/metabolism , Matrix Metalloproteinase 8/metabolism , Nasal Polyps/physiopathology , Rhinitis/complications , Rhinitis/physiopathology , Sinusitis/complications , Sinusitis/physiopathology , Aged , Chronic Disease , Female , Humans , Male , Middle Aged , Nasal Mucosa/metabolism , Paranasal Sinuses/metabolism , Tumor Necrosis Factor-alpha/metabolism , Up-Regulation
19.
Phys Rev Lett ; 95(3): 032501, 2005 Jul 15.
Article in English | MEDLINE | ID: mdl-16090736

ABSTRACT

In-beam gamma-ray spectroscopic measurements have been made on 253/102No. A single rotational band was identified up to a probable spin of 39/2planck, which is assigned to the 7/2(+)[624] Nilsson configuration. The bandhead energy and the moment of inertia provide discriminating tests of contemporary models of the heaviest nuclei. Novel methods were required to interpret the sparse data set associated with cross sections of around 50 nb. These methods included comparisons of experimental and simulated spectra, as well as testing for evidence of a rotational band in the gammagamma matrix.

20.
Theor Appl Genet ; 109(2): 272-9, 2004 Jul.
Article in English | MEDLINE | ID: mdl-15071729

ABSTRACT

Somatic Brassica napus (+) Arabidopsis thaliana hybrids with a cytoplasmic male sterility (CMS)-inducing cytoplasm were screened for fertility-restored plants. One line was selected and recurrently backcrossed with the maintainer line, B. napus, resulting in fertile/sterile segregating populations. Restriction fragment length polymorphism mapping showed the co-segregation of A. thaliana chromosome (chr) III markers with the fertility trait. As it was not possible to stabilise the fertility trait via selfings, a dihaploidisation strategy was assessed. Ninety haploid plants were regenerated and analysed with numerous simple sequence length polymorphism (SSLP) markers. Markers covering both arms of A. thaliana chr III were present in two plants, whereas no A. thaliana DNA could be detected in the other plants. Following colchicine-induced chromosome doubling only these two plants with A. thaliana DNA produced fertile offspring. In one of the two lines, however, the A. thaliana-specific DNA markers and fertility were lost in subsequent generations. The other line remained fertile after repeated selfings. Using genomic in situ hybridisation (GISH) we were able to demonstrate that this latter line possessed a disomic addition of the A. thaliana chromosome. The restored line was comparable to the maintainer line with respect to flower morphology, but the petals and stamens were slightly reduced in size. The homeotic conversion of stamens to pistil-like structures, which is typical for the CMS line, was reversed, and stamens with a normal appearance with viable pollen appeared. Flowering time was as in the CMS line-in both lines it was delayed in comparison to the maintainer line. The introgressed chromosome also contributes to several pleiotropic effects, such as reduced leaf crinkling and shorter stems. The ability to restore fertility through the introgression of nuclear genes from the main cytoplasmic donor species indicates that the CMS trait in this system mainly is due to B. napus/ A. thaliana alloplasmic incompatibility and not mitochondrial DNA rearrangements. Further exploitation of the material is discussed.


Subject(s)
Arabidopsis/genetics , Brassica napus/genetics , Chromosomes, Plant/genetics , DNA, Mitochondrial/genetics , Phenotype , Blotting, Southern , Brassica napus/anatomy & histology , Chromosome Mapping , Crosses, Genetic , Cytogenetic Analysis , DNA Primers , Electrophoresis, Agar Gel , Fertility/genetics , In Situ Hybridization , Plants, Genetically Modified , Polymorphism, Restriction Fragment Length
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