Selection of hydroxyproline-resistant proline-accumulating mutants of cauliflower. C.R. Deane, M .P. Fuller' & P.J. Dix

A procedure is described by which hydroxyproline-resistant lines could be selected from regenerating curd tissue of cauliflower. Mutagenesis was by N-nitroso-N-ethylurea, supplied as a drop of 0 .3 mM solution on each 3 mm diameter curd piece. The mutagen generated numerous morphological and pigment mutations without significantly affecting shoot regeneration from explants . Thirty one resistant shoots were recovered from more than six thousand explants mutagenised on regeneration medium supplemented with 3 mM hydroxyproline, while none was obtained from a similar number of non-mutagenised controls . Out of twenty-three resistant shoots which survived subculture, only one showed consistently elevated levels of endogenous proline . During early shoot culture passages, proline levels were 3 .6-4.7 times higher than controls, but this was reduced to 1 .6 times after 10-12 culture passages in the absence of hydroxyproline . Possible reasons for this decline are discussed . Leaf strip assays suggest resistant shoots may be chimeras and current efforts are directed towards regenerating solid mutants from resistant sectors . These will then be evaluated for any alteration in frost tolerance

Selection of hydroxyproline-resistant proline-accumulating mutants of cauliflower. C.R. Deane, M .P. Fuller' & P.J. Dix

A procedure is described by which hydroxyproline-resistant lines could be selected from regenerating curd tissue of cauliflower. Mutagenesis was by N-nitroso-N-ethylurea, supplied as a drop of 0 .3 mM solution on each 3 mm diameter curd piece. The mutagen generated numerous morphological and pigment mutations without significantly affecting shoot regeneration from explants . Thirty one resistant shoots were recovered from more than six thousand explants mutagenised on regeneration medium supplemented with 3 mM hydroxyproline, while none was obtained from a similar number of non-mutagenised controls . Out of twenty-three resistant shoots which survived subculture, only one showed consistently elevated levels of endogenous proline . During early shoot culture passages, proline levels were 3 .6-4.7 times higher than controls, but this was reduced to 1 .6 times after 10-12 culture passages in the absence of hydroxyproline . Possible reasons for this decline are discussed . Leaf strip assays suggest resistant shoots may be chimeras and current efforts are directed towards regenerating solid mutants from resistant sectors . These will then be evaluated for any alteration in frost tolerance

In vitro strategies for improvement of frost tolerance in cauliflower.

Two in vitro selection strategies were employed in an effort to obtain cauliflower lines with improved cold tolerance

Bone stable isotope evidence for infant feeding in Mediaeval England

This paper is a first study of duration of breastfeeding using bone stable isotopes in infants in a British palaeopopulation, from the deserted Mediaeval village of Wharram Percy, England. Nitrogen stable isotope analysis suggests cessation of breastfeeding between 1 and 2 years of age. Comparison with Mediaeval documentary sources suggests that recommendations of physicians regarding infant feeding may have influenced common practice in this period

In vitro strategies for improvement of frost tolerance in cauliflower.

Two in vitro selection strategies were employed in an effort to obtain cauliflower lines with improved cold tolerance

EFFECT OF NITROGEN ON SAFFLOWER PHYSIOLOGY AND PRODUCTIVITY

Safflower ( Carthamus tinctorius ) L. is an oil-crop suitable for semi-arid agriculture, but its physiological re- sponse to agronomic inputs has yet to be fully evaluated. The effect of fertiliser on the physiology and produc- tion of Safflower grown in pots filled with standard grade perlite inside a semi-controlled glass house was studied. Plants were initially irrigated with 20-100 ml standard hydroponic solution and then one month after germination plants were irrigated using 50-200 ml complete Hoagland\u2019s solution, supplemented with one of eight levels of nitrogen (0, 25, 50, 75, 100, 125, 150, 175 kg N ha-1) in the form of ammonium nitrate. Elevating nitrogen to 100 kg N ha-1 significantly increased the assimilation rate by about 42 %, transpiration rate by 32%, stomatal conductance by 52% and LAI by 42% compared with the control. The above ground dry weight, seed yield and Water Use Efficiency (WUE) increased incrementally with increases in nitrogen rate. Above ground dry weight increased by an average of 42%, seed yield by 76% and WUE by 41% at harvest compared with the control. This study clearly demonstrates how nitrogen fertilisation can affect physiology of Safflower leading to im- provement in seed yield.Le carthame ( Carthamus tinctorius ) L.) est une culture ol\ue9agineuse appropri\ue9e \ue0 l\u2019agriculture semi aride, mais sa r\ue9ponse physiologique aux intrants agronomiques reste \ue0 \ue9valuer. L\u2019effet de fertilisants sur la physiologie et la production du carthame cultiv\ue9 en pots rempli de perlites de niveau standard \ue0 l\u2019int\ue9rieur d\u2019une serre semi contr\uf4l\ue9e \ue9tait \ue9tudi\ue9. Les plants \ue9taient initialement irrigu\ue9s avec 20-100 ml de solution hydroponique standard et, ensuite, un mois apr\ue8s la germination des plants \ue9taient irrigu\ue9s avec 50-200 ml de solution de Hoagland compl\ue8te et un suppl\ue9ment de huit niveau d\u2019azote (0, 25, 50, 75, 100, 125, 150, 175 kg N ha-1) sous forme du nitrate d\u2019ammonium. L\u2019utilisation de la dose de 100 kg N ha-1 a significativement accru le taux d\u2019assimilation d\u2019environ 42 %, le taux de transpiration de 32 %, la conductance stomatale de 52 % et l\u2019index de la surface foliaire de 42 % en comparaison avec le t\ue9moin. Le poids sec de la biomasse a\ue9rienne, le rendement en grain et le Water Use Efficieny (WUE) avait augment\ue9 avec la dose d\u2019azote. Le poids sec de la biomasse a\ue9rienne a en moyenne augment\ue9 de 42% pendant que le rendement en grains et le WAE ont augment\ue9 \ue0 la r\ue9colte de 76% et 41% , respectivement, en comparaison avec le t\ue9moin. Cette \ue9tude d\ue9montre clairement comment la fertilisation azot\ue9e peut affecter la physiologie du carthame conduisant \ue0 l\u2019am\ue9lioration du rendement en grains

Refractive elastic scattering of carbon and oxygen nuclei: The mean field analysis and Airy structures

The experimental data on the $^{16}$O$+^{12}$C and $^{18}$O$+^{12}$C elastic scatterings and their optical model analysis are presented. Detailed and complete elastic angular distributions have been measured at the Strasbourg Vivitron accelerator at several energies covering the energy range between 5 and 10 MeV per nucleon. The elastic scattering angular distributions show the usual diffraction pattern and also, at larger angles, refractive effects in the form of nuclear rainbow and associated Airy structures. The optical model analysis unambiguously shows the evolution of the refractive scattering pattern. The observed structure, namely the Airy minima, can be consistently described by a nucleus-nucleus potential with a deep real part and a weakly absorptive imaginary part. The difference in absorption in the two systems is explained by an increased imaginary (mostly surface) part of the potential in the $^{18}$O$+^{12}$C system. The relation between the obtained potentials and those reported for the symmetrical $^{16}$O$+^{16}$O and $^{12}$C$+^{12}$C systems is drawn.Comment: 10 pages, 9 figures, Phys. rev. C in pres

Airy-like patterns in heavy ion elastic scattering

A semiclassical analysis of an optical potential cross section is presented. The cross section considered is characterized by the appearance of an Airy-like pattern. This pattern is similar to that which is present in many cross sections, which fit the recent measurements of light heavy ion elastic scattering, and is considered as a manifestation of a rainbow phenomenon. The semiclassical analysis shows that, in the case considered, the oscillations arise from the interference between the contributions from two different terms of a multi-reflection expansion of the scattering function, and, therefore, cannot be associated with the rainbow phenomenon.Comment: 10 pages, 5 figure

Improved Nearside-Farside Decomposition of Elastic Scattering Amplitudes

A simple technique is described, that provides improved nearside-farside (NF) decompositions of elastic scattering amplitudes. The technique, involving the resummation of a Legendre partial wave series, reduces the importance of unphysical contributions to NF subamplitudes, which can arise in more conventional NF decompositions. Applications are made to a strong absorption model and to a $^{16}$O + $^{12}$C optical potential at $E_{\text{lab}} = 132$ MeV.Comment: 5 pages, 2 figure

Heading Frequency and Risk of Cognitive Impairment in Retired Male Professional Soccer Players

Importance Although professional soccer players appear to be at higher risk of neurodegenerative disease, the reason remains unknown.Objective To examine whether heading frequency is associated with risk of cognitive impairment in retired professional soccer players.Design, Setting, and Participants A UK nationwide cross-sectional study was conducted between August 15, 2020, and December 31, 2021, in 459 retired male professional soccer players older than 45 years and registered with the Professional Footballers’ Association or a League Club Players’ Association.Exposure Data on heading frequency in 3 bands—0 to 5, 6 to 15, and more than 15 times per match or training session and other soccer-specific risk factors, such as player position and concussion—were collected through a self-reported questionnaire.Main Outcomes and Measures Cognitive impairment was defined using the Telephone Interview for Cognitive Status-modified as scores of less than or equal to 21. Hopkins Verbal Learning Test, verbal fluency, and independent activities of daily living were also assessed. Test Your Memory and physician-diagnosed dementia/Alzheimer disease were self-reported via the questionnaire. Adjusted odds ratios (AORs) with 95% CIs were calculated.Results Of 468 retired male professional soccer players who completed questionnaires (mean [SD] age, 63.68 [10.48]; body mass index, 27.22 [2.89]), 459 reported heading frequency: 114 headed 0 to 5 times, 185 headed 6 to 15 times, 160 headed more than 15 times per match, and 125 headed 0 to 5 times, 174 headed 6 to 15 times, and 160 headed more than 15 times per training session during their careers. The prevalence of cognitive impairment was 9.78% (0-5 times), 14.78% (6-15 times), and 15.20% (>15 times) per match (P = .51). Compared with players reporting 0 to 5 headers per match, the AORs were 2.71 (95% CI, 0.89-8.25) for players reporting 6 to 15 headers per match and 3.53 (95% CI, 1.13-11.04) for players reporting more than 15 headers per match (P = .03 for trend). Corresponding AORs for heading frequency per training session were 2.38 (95% CI, 0.82-6.95) for those reporting 6 to 15, and 3.40 (95% CI, 1.13-10.23) for those reporting more than 15 in comparison with those who reported 0 to 5 (P = .03 for trend). Concussion involving memory loss was also associated with a greater risk of cognitive impairment (AOR, 3.16; 95% CI, 1.08-9.22). Similar results were observed with other cognitive tests and self-reported physician-diagnosed dementia/Alzheimer disease.Conclusions and Relevance The findings of this study suggest that repetitive heading during a professional soccer career is associated with an increased risk of cognitive impairment in later life. Further study is needed to establish the upper threshold for heading frequency to mitigate this risk