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1.
Phys Rev Lett ; 131(21): 212501, 2023 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-38072612

RESUMEN

The cluster structure of the neutron-rich isotope ^{10}Be has been probed via the (p,pα) reaction at 150 MeV/nucleon in inverse kinematics and in quasifree conditions. The populated states of ^{6}He residues were investigated through missing mass spectroscopy. The triple differential cross section for the ground-state transition was extracted for quasifree angle pairs (θ_{p},θ_{α}) and compared to distorted-wave impulse approximation reaction calculations performed in a microscopic framework using successively the Tohsaki-Horiuchi-Schuck-Röpke product wave function and the wave function deduced from antisymmetrized molecular dynamics calculations. The remarkable agreement between calculated and measured cross sections in both shape and magnitude validates the molecular structure description of the ^{10}Be ground-state, configured as an α-α core with two valence neutrons occupying π-type molecular orbitals.

2.
Phys Rev Lett ; 131(26): 262501, 2023 Dec 29.
Artículo en Inglés | MEDLINE | ID: mdl-38215380

RESUMEN

The excited states of unstable ^{20}O were investigated via γ-ray spectroscopy following the ^{19}O(d,p)^{20}O reaction at 8 AMeV. By exploiting the Doppler shift attenuation method, the lifetimes of the 2_{2}^{+} and 3_{1}^{+} states were firmly established. From the γ-ray branching and E2/M1 mixing ratios for transitions deexciting the 2_{2}^{+} and 3_{1}^{+} states, the B(E2) and B(M1) were determined. Various chiral effective field theory Hamiltonians, describing the nuclear properties beyond ground states, along with a standard USDB interaction, were compared with the experimentally obtained data. Such a comparison for a large set of γ-ray transition probabilities with the valence space in medium similarity renormalization group ab initio calculations was performed for the first time in a nucleus far from stability. It was shown that the ab initio approaches using chiral effective field theory forces are challenged by detailed high-precision spectroscopic properties of nuclei. The reduced transition probabilities were found to be a very constraining test of the performance of the ab initio models.

3.
Phys Rev Lett ; 124(21): 212503, 2020 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-32530691

RESUMEN

The heaviest bound isotope of boron ^{19}B has been investigated using exclusive measurements of its Coulomb dissociation, into ^{17}B and two neutrons, in collisions with Pb at 220 MeV/nucleon. Enhanced electric dipole (E1) strength is observed just above the two-neutron decay threshold with an integrated E1 strength of B(E1)=1.64±0.06(stat)±0.12(sys) e^{2} fm^{2} for relative energies below 6 MeV. This feature, known as a soft E1 excitation, provides the first firm evidence that ^{19}B has a prominent two-neutron halo. Three-body calculations that reproduce the energy spectrum indicate that the valence neutrons have a significant s-wave configuration and exhibit a dineutronlike correlation.

4.
Phys Rev Lett ; 121(26): 262502, 2018 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-30636115

RESUMEN

The most neutron-rich boron isotopes ^{20}B and ^{21}B have been observed for the first time following proton removal from ^{22}N and ^{22}C at energies around 230 MeV/nucleon. Both nuclei were found to exist as resonances which were detected through their decay into ^{19}B and one or two neutrons. Two-proton removal from ^{22}N populated a prominent resonancelike structure in ^{20}B at around 2.5 MeV above the one-neutron decay threshold, which is interpreted as arising from the closely spaced 1^{-},2^{-} ground-state doublet predicted by the shell model. In the case of proton removal from ^{22}C, the ^{19}B plus one- and two-neutron channels were consistent with the population of a resonance in ^{21}B 2.47±0.19 MeV above the two-neutron decay threshold, which is found to exhibit direct two-neutron decay. The ground-state mass excesses determined for ^{20,21}B are found to be in agreement with mass surface extrapolations derived within the latest atomic-mass evaluations.

5.
Phys Rev Lett ; 116(10): 102503, 2016 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-27015476

RESUMEN

The unbound nucleus ^{26}O has been investigated using invariant-mass spectroscopy following one-proton removal reaction from a ^{27}F beam at 201 MeV/nucleon. The decay products, ^{24}O and two neutrons, were detected in coincidence using the newly commissioned SAMURAI spectrometer at the RIKEN Radioactive Isotope Beam Factory. The ^{26}O ground-state resonance was found to lie only 18±3(stat)±4(syst) keV above threshold. In addition, a higher lying level, which is most likely the first 2^{+} state, was observed for the first time at 1.28_{-0.08}^{+0.11} MeV above threshold. Comparison with theoretical predictions suggests that three-nucleon forces, pf-shell intruder configurations, and the continuum are key elements to understanding the structure of the most neutron-rich oxygen isotopes beyond the drip line.

6.
Environ Pollut ; 200: 93-104, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25703579

RESUMEN

In recent decades, naturally growing mosses have been used successfully as biomonitors of atmospheric deposition of heavy metals and nitrogen. Since 1990, the European moss survey has been repeated at five-yearly intervals. In 2010, the lowest concentrations of metals and nitrogen in mosses were generally found in northern Europe, whereas the highest concentrations were observed in (south-)eastern Europe for metals and the central belt for nitrogen. Averaged across Europe, since 1990, the median concentration in mosses has declined the most for lead (77%), followed by vanadium (55%), cadmium (51%), chromium (43%), zinc (34%), nickel (33%), iron (27%), arsenic (21%, since 1995), mercury (14%, since 1995) and copper (11%). Between 2005 and 2010, the decline ranged from 6% for copper to 36% for lead; for nitrogen the decline was 5%. Despite the Europe-wide decline, no changes or increases have been observed between 2005 and 2010 in some (regions of) countries.


Asunto(s)
Contaminantes Atmosféricos/análisis , Contaminación del Aire/estadística & datos numéricos , Briófitas/química , Monitoreo del Ambiente , Metales Pesados/análisis , Nitrógeno/análisis , Cadmio/análisis , Europa (Continente) , Hierro , Mercurio , Metales , Níquel
7.
Environ Pollut ; 184: 113-22, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24047547

RESUMEN

Polycyclic aromatic hydrocarbon (PAH) concentrations and N, C stable isotope signatures were determined in mosses Hypnum cupressiforme Hedw. from 61 sites of 3 European regions: Île-de-France (France); Navarra (Spain); the Swiss Plateau and Basel area (Switzerland). Total PAH concentrations of 100-700 ng g(-1), as well as δ(13)C values of -32 to -29‰ and δ(15)N values of -11 to -3‰ were measured. Pearson correlation tests revealed opposite trends between high molecular weight PAH (4-6 aromatic rings) content and δ(13)C values. Partial Least Square regressions explained the very significant correlations (r > 0.91, p < 0.001) between high molecular weight PAH concentrations by local urban land use (<10 km) and environmental factors such as elevation and pluviometry. Finally, specific correlations between heavy metal and PAH concentrations were attributed to industrial emissions in Switzerland and road traffic emissions in Spain.


Asunto(s)
Contaminantes Atmosféricos/análisis , Briófitas/química , Bryopsida/química , Monitoreo del Ambiente , Hidrocarburos Policíclicos Aromáticos/análisis , Contaminación del Aire/estadística & datos numéricos , Isótopos de Carbono/análisis , Francia , Industrias , Metales Pesados/análisis , Análisis Multivariante , Isótopos de Nitrógeno/análisis , España , Suiza
8.
Sci Total Environ ; 439: 87-95, 2012 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-23063913

RESUMEN

The inputs of ten trace elements (As, Cd, Cu, Cr, Hg, Mo, Ni, Pb, Se, Zn) to French agricultural soils have been assessed. The six main sources considered were: pesticides, mineral fertilizers, animal manure, liming materials, sludge and composts and atmospheric deposition. Data were collected to compute inputs at both national and regional (departmental) scales. The inventory methodology is based on two principles: data are traceable and easy to update. At a national scale, the inventory showed that trace elements inputs can be ranked: Zn≫Cu≫Cr>Pb>Ni>As=Mo>Se>Cd>Hg. Animal manure, mineral fertilizers and pesticides are the predominant sources of TEs. These results are globally in agreement with literature data though atmospheric deposition is shown to be lower than in more industrial countries such as China and United Kingdom where similar surveys were conducted. The inputs of trace elements vary strongly between regions in relation with agricultural activities. This inventory (and the related database) provides basis for developing and monitoring policies to control and reduce trace elements contamination of agricultural soils at both national and regional (departmental) scales.


Asunto(s)
Agricultura/normas , Monitoreo del Ambiente/métodos , Contaminantes del Suelo/análisis , Suelo , Oligoelementos/análisis , Compuestos de Calcio/análisis , Compuestos de Calcio/química , Fertilizantes/análisis , Francia , Estiércol/análisis , Óxidos/análisis , Óxidos/química , Plaguicidas/análisis , Plaguicidas/química , Aguas del Alcantarillado/análisis , Aguas del Alcantarillado/química , Suelo/análisis , Suelo/normas
9.
Environ Pollut ; 166: 1-9, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22459708

RESUMEN

Previous analyses at the European scale have shown that cadmium and lead concentrations in mosses are primarily determined by the total deposition of these metals. Further analyses in the current study show that Spearman rank correlations between the concentration in mosses and the deposition modelled by the European Monitoring and Evaluation Programme (EMEP) are country and metal-specific. Significant positive correlations were found for about two thirds or more of the participating countries in 1990, 1995, 2000 and 2005 (except for Cd in 1990). Correlations were often not significant and sometimes negative in countries where mosses were only sampled in a relatively small number of EMEP grids. Correlations frequently improved when only data for EMEP grids with at least three moss sampling sites per grid were included. It was concluded that spatial patterns and temporal trends agree reasonably well between lead and cadmium concentrations in mosses and modelled atmospheric deposition.


Asunto(s)
Contaminantes Atmosféricos/análisis , Contaminación del Aire/estadística & datos numéricos , Atmósfera/química , Briófitas/química , Cadmio/análisis , Plomo/análisis , Modelos Químicos , Monitoreo del Ambiente , Europa (Continente)
10.
Environ Pollut ; 159(10): 2852-60, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21620544

RESUMEN

In 2005/6, nearly 3000 moss samples from (semi-)natural location across 16 European countries were collected for nitrogen analysis. The lowest total nitrogen concentrations in mosses (<0.8%) were observed in northern Finland and northern UK. The highest concentrations (≥ 1.6%) were found in parts of Belgium, France, Germany, Slovakia, Slovenia and Bulgaria. The asymptotic relationship between the nitrogen concentrations in mosses and EMEP modelled nitrogen deposition (averaged per 50 km × 50 km grid) across Europe showed less scatter when there were at least five moss sampling sites per grid. Factors potentially contributing to the scatter are discussed. In Switzerland, a strong (r(2) = 0.91) linear relationship was found between the total nitrogen concentration in mosses and measured site-specific bulk nitrogen deposition rates. The total nitrogen concentrations in mosses complement deposition measurements, helping to identify areas in Europe at risk from high nitrogen deposition at a high spatial resolution.


Asunto(s)
Contaminantes Atmosféricos/análisis , Atmósfera/química , Briófitas/química , Monitoreo del Ambiente/métodos , Nitrógeno/análisis , Contaminación del Aire/estadística & datos numéricos , Europa (Continente)
11.
Environ Pollut ; 158(10): 3144-56, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20674112

RESUMEN

In recent decades, mosses have been used successfully as biomonitors of atmospheric deposition of heavy metals. Since 1990, the European moss survey has been repeated at five-yearly intervals. Although spatial patterns were metal-specific, in 2005 the lowest concentrations of metals in mosses were generally found in Scandinavia, the Baltic States and northern parts of the UK; the highest concentrations were generally found in Belgium and south-eastern Europe. The recent decline in emission and subsequent deposition of heavy metals across Europe has resulted in a decrease in the heavy metal concentration in mosses for the majority of metals. Since 1990, the concentration in mosses has declined the most for arsenic, cadmium, iron, lead and vanadium (52-72%), followed by copper, nickel and zinc (20-30%), with no significant reduction being observed for mercury (12% since 1995) and chromium (2%). However, temporal trends were country-specific with sometimes increases being found.


Asunto(s)
Briófitas/química , Monitoreo del Ambiente , Contaminantes Ambientales/análisis , Metales Pesados/análisis , Atmósfera/química , Contaminación Ambiental/estadística & datos numéricos , Europa (Continente) , Lluvia/química , Nieve/química
12.
Can Med Assoc J ; 116(11): 1284-8, 1290, 1977 Jun 04.
Artículo en Francés | MEDLINE | ID: mdl-324591

RESUMEN

In 1773 an epidemic disease with cutaneous manifestations appeared in Baie Saint-Paul, Québec and spread rapidly from nearby les Eboulements to the entire island of Montreal. The epidemic was in many ways reminiscent of a typical outbreak of syphilis, a condition then well known in Europe. Dr. Charles Blake of Montreal, as well as Drs. James Bowman and Philippe Badelart of Quebec, would not acknowledge any other diagnosis. The latter two physicians were commissioned by General Haldimand, governor of Canada, to investigate and treat this new disease. Patients were often cured by potions or ointments containing mercury if used from the onset of symptoms. However, Dr. Robert Jones, another physician from Montreal, submitted a different opinion: the clinical course of the disease, the anomalies of its transmission, its sometimes intriguing sequelae and its unpredictable response to mercurial therapy led him to believe that it might be an entity entirely different from syphilis as it was then known in Europe. Half a century earlier, in Scotland, a similar outbreak had occurred for which the same reservation had been made with regard to a possible diagnosis of syphilis.


Asunto(s)
Brotes de Enfermedades/historia , Sífilis/historia , Femenino , Historia del Siglo XVIII , Humanos , Masculino , Quebec
13.
Hum Genet ; 86(5): 457-62, 1991 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-2016086

RESUMEN

Recent studies have shown the gene encoding creatine kinase isoform M (CKMM) to be very closely linked to the myotonic dystrophy (DM) locus on the long arm of chromosome 19. Given this close linkage to DM and the postulated role of CKMM in skeletal muscle contraction, the possibility of a defect in CKMM causing DM was investigated. CKMM cDNA was isolated from the skeletal muscle of an individual with DM. Sequencing of the CKMM cDNA from the DM chromosome 19 revealed two novel polymorphisms but no translationally significant mutation. This work rules out a defect in the coding segment of CKMM as a cause of DM in this family and, in light of genetic homogeneity shown to date for DM, probably in all cases of DM.


Asunto(s)
Creatina Quinasa/genética , Distrofia Miotónica/genética , Polimorfismo Genético , Secuencia de Aminoácidos , Secuencia de Bases , Cromosomas Humanos Par 19 , Clonación Molecular , ADN , Femenino , Humanos , Isoenzimas , Masculino , Datos de Secuencia Molecular , Distrofia Miotónica/enzimología , Linaje , Reacción en Cadena de la Polimerasa
14.
Hum Hered ; 41(3): 188-94, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-1682238

RESUMEN

The gene for human apolipoprotein CII (APOCII) is located on the proximal long arm of chromosome 19. It has been established as a closely linked marker for myotonic dystrophy (DM), the most common form of adult muscular dystrophy. In the present linkage study, we have analysed 6 APOCII RFLPs in 213 haplotypes: TaqI, 3.8/3.5 kb; BgII, 12.0/9.0 kb; BanI, 2.5/1.6 kb; BamHI, 6.0/4.9 kb; NcoI, 14.5/11.5 kb, and AvaII, 0.6/0.4 kb. The polymorphic enzyme sites were determined to be present at the following frequencies: TaqI, 0.43; BglI, 0.51; BanI, 0.25; BamHI, 0.99; NcoI, 0.51, and AvaII, 0.52. Ordering of the polymorphic sites, 5'----3', has been determined to be (NcoI-BglI)-AvaII-BanI-TaqI. Significant disequilibrium was seen between 5 of the APOCII RFLPs.


Asunto(s)
Apolipoproteínas C/genética , Mapeo Cromosómico , Cromosomas Humanos Par 19 , ADN/genética , Desequilibrio de Ligamiento/genética , Polimorfismo Genético/genética , Alelos , Apolipoproteína C-II , Secuencia de Bases , Humanos , Datos de Secuencia Molecular , Polimorfismo de Longitud del Fragmento de Restricción
15.
Am J Hum Genet ; 49(5): 961-5, 1991 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-1928101

RESUMEN

Recent genetic linkage studies have mapped the myotonic dystrophy (DM) locus to 19q13.3. All closely linked DM markers identified to date have been located on the centromeric side of the disease locus, with a relatively large genetic interval (9 cM) observed between the nearest distal marker and DM. We show here that the recently described marker p134C is tightly linked to DM (peak lod score 35.8 at peak recombination fraction .006) and confirm the previous suggestion that the p134C locus, D19S51 maps distal to the disease locus. D19S51 and the closest proximal flanking loci, ERCC1 and D19S115 (pE0.8), define a small genetic interval of less than 2 cM that contains the DM locus.


Asunto(s)
Cromosomas Humanos Par 19 , Marcadores Genéticos , Distrofias Musculares/genética , Mapeo Cromosómico , Femenino , Ligamiento Genético , Humanos , Masculino , Linaje
16.
Genomics ; 9(3): 500-4, 1991 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-1674498

RESUMEN

Recent genetic linkage analyses have mapped the myotonic dystrophy locus to the region of 19q13.2-13.3 lying distal to the gene for creatine kinase subunit M (CKM). The human excision repair gene ERCC1 has also been mapped to this region of chromosome 19. A novel polymorphic DNA marker, pEO.8, has been isolated from a chromosome 19 ERCC1-containing cosmid that maps to a 300-kb NotI fragment encompassing both CKM and ERCC1. Genetic linkage analysis reveals close linkage between pEO.8 and myotonic dystrophy (DM) (zmax = 19.3, theta max = 0.01). Analysis of two key recombinant events suggests a mapping of DM distal to pEO.8 and CKM.


Asunto(s)
Cromosomas Humanos Par 19 , Reparación del ADN/genética , Marcadores Genéticos/genética , Distrofia Miotónica/genética , Southern Blotting , Canadá , Mapeo Cromosómico , Creatina Quinasa/genética , Sondas de ADN , Ligamiento Genético , Humanos , Países Bajos , Linaje , Polimorfismo de Longitud del Fragmento de Restricción , Recombinación Genética
17.
Am J Hum Genet ; 46(6): 1082-9, 1990 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-1971150

RESUMEN

The recent cloning of cDNA encoding the Ca++ release channel (ryanodine receptor) of human sarcoplasmic reticulum has enabled us to use somatic cell hybrids to localize the ryanodine receptor gene (RYR) to the proximal long arm of human chromosome 19. Studies with additional hybrids containing deletions or translocations in chromosome 19 enabled us to localize RYR to 19q13.1 in a region distal to GPI/MAG and proximal to D19S18/DNF11. On the basis that the myotonic dystrophy (DM) locus maps near this region and that myotonia could result from a defect in the ryanodine receptor, we examined the linkage between the DM locus and RYR. Our results, showing several DM-RYR recombinants, rule out an RYR defect as the cause of DM. However, localization of RYR to a region of human chromosome 19 which is syntenic to an area of pig chromosome 6 containing the HAL gene responsible for porcine malignant hyperthermia supports the candidacy of RYR for this disorder.


Asunto(s)
Cromosomas Humanos Par 19 , Ligamiento Genético , Distrofia Miotónica/genética , Receptores Colinérgicos/genética , Southern Blotting , Calcio , Mapeo Cromosómico , Femenino , Genes , Humanos , Células Híbridas , Escala de Lod , Masculino , Linaje , Polimorfismo de Longitud del Fragmento de Restricción , Recombinación Genética , Canal Liberador de Calcio Receptor de Rianodina
19.
Laval Med ; 38(2): 183-91, 1967 Feb.
Artículo en Francés | MEDLINE | ID: mdl-4882367
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