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Nuclear charge radii are sensitive probes of different aspects of the nucleon-nucleon interaction and the bulk properties of nuclear matter; thus, they provide a stringent test and challenge for nuclear theory. The calcium region has been of particular interest, as experimental evidence has suggested a new magic number at $N = 32$ [1-3], while the unexpectedly large increases in the charge radii [4,5] open new questions about the evolution of nuclear size in neutron-rich systems. By combining the collinear resonance ionization spectroscopy method with $\beta$-decay detection, we were able to extend the charge radii measurement of potassium ($Z =19$) isotopes up to the exotic $^{52}$K ($t_{1/2}$ = 110 ms), produced in minute quantities. Our work provides the first charge radii measurement beyond $N = 32$ in the region, revealing no signature of the magic character at this neutron number. The results are interpreted with two state-of-the-art nuclear theories. For the first time, a long sequence of isotopes could be calculated with coupled-cluster calculations based on newly developed nuclear interactions. The strong increase in the charge radii beyond $N = 28$ is not well captured by these calculations, but is well reproduced by Fayans nuclear density functional theory, which, however, overestimates the odd-even staggering effect. These findings highlight our limited understanding on the nuclear size of neutron-rich systems, and expose pressing problems that are present in some of the best current models of nuclear theory., Comment: submitted version; revision accepted in Nature Physics

© 2019 This paper presents an overview of recent resonance ionization schemes used at the Collinear Resonance Ionization Spectroscopy (CRIS) setup located at ISOLDE, CERN. The developments needed to reach high spectral resolution and efficiency will be discussed. Besides laser ionization efficiency and high resolving power, experiments on rare isotopes also require low-background conditions. Ongoing developments that aim to deal with beam-related sources of background are presented. ispartof: Nuclear Instruments & Methods In Physics Research Section B-Beam Interactions With Materials And Atoms vol:463 pages:398-402 ispartof: location:SWITZERLAND, CERN, Geneva status: published

Veterinary certificates have been an integral component of animal and animal product trade for many years. These certificates are agreed to by trading partners during bilateral or multilateral negotiations on the trade of animals and animal products, and provide assurance that goods are free from specific diseases. Many countries seek to implement or adopt a more streamlined and secure method of information exchange, with some implementing the electronic exchange of certificates for cross-border trade. Such an exchange of data has many advantages over its paper counterpart, including a streamlined business process, better accessibility to information (particularly in advance of shipment arrival) and the reduction of fraudulent certificates. Although there are some challenges related to this initiative and important considerations to be taken into account for its implementation, many countries are becoming aware of its efficiencies, leading to more productive and mutually beneficial trading-partner relationships.Les certificats vétérinaires sont une composante essentielle des échanges internationaux d’animaux et de produits d’origine animale depuis de nombreuses années. Il s’agit de certificats approuvés préalablement par les partenaires commerciaux lors de négociations bilatérales ou multilatérales relatives aux échanges d’animaux et de produits d’origine animale et qui apportent la garantie que les marchandises échangées sont indemnes de certaines maladies spécifiées. Plusieurs pays ont cherché à mettre en oeuvre ou à valider une procédure d’échange d’informations à la fois plus simple et plus sûre ; parmi eux certains ont mis en place un système de certification électronique pour les échanges transfrontaliers. Ce type de transmission de données présente de nombreux avantages par rapport à la délivrance de certificats papier : un processus opérationnel rationalisé, un meilleur accès à l’information (en particulier avant l’arrivée d’une cargaison) et un nombre réduit de certificats frauduleux. Bien que certains problèmes en lien avec cette initiative restent encore à résoudre et que plusieurs aspects importants devront être pris en compte lors de sa mise en oeuvre, un nombre croissant de pays prennent conscience du fait que les performances d’un tel système contribueront à des relations plus productives et mutuellement bénéfiques entre partenaires commerciaux.Hace ya muchos años que los certificados veterinarios son un componente intrínseco del comercio de animales y productos de origen animal. Estos certificados, acordados por las partes en el curso de negociaciones bilaterales o multilaterales sobre ese tipo de comercio, aportan la garantía de que las mercancías están exentas de una u otra enfermedad. Muchos países están tratando de aplicar o adoptar un método más ágil y seguro para intercambiar información, y algunos están implantando el intercambio de certificados por vía electrónica para operaciones comerciales transfronterizas. Esta modalidad de transmisión de datos presenta muchas ventajas con respecto al uso del papel, en particular porque agiliza los procesos de trabajo, facilita el acceso a la información (en particular, antes de que llegue la mercancía) y reduce los casos de certificados fraudulentos. Aunque esta iniciativa no deja de presentar dificultades y hay importantes consideraciones que es preciso tener en cuenta para llevarla adelante, muchos países van cobrando conciencia de que trae consigo procesos más eficientes y se traduce en relaciones más productivas y mutuamente beneficiosas entre los socios comerciales.

A gas-filled linear Paul trap for the Collinear Resonance Ionisation Spectroscopy (CRIS) experiment at ISOLDE, CERN is currently under development. The trap is designed to accept beam from both ISOLDE target stations and the CRIS stable ion source. The motivation for the project along with the current design, simulations and future plans, will be outlined. peerReviewed

Rydberg positronium (Ps) atoms have been prepared in selected Stark states via two-step (1s→2p→nd/ns) optical excitation. Two methods have been used to achieve Stark-state selection: a field ionization filter that transmits the outermost states with positive Stark shifts, and state-selected photoexcitation in a strong electric field. The former is demonstrated for n=17 and 18 while the latter is performed for n=11 in a homogeneous electric field of 1.9 kV/cm. The observed spectral intensities and their dependence on the polarization of the laser radiation are in agreement with calculations that include the perturbations of the intermediate n=2 manifold. Our results pave the way for the generation of Rydberg Ps atoms with large electric dipole moments that are required for the realization of schemes to control their motion using inhomogeneous electric fields, an essential feature of some proposed Ps free-fall measurements requiring focused beams of long-lived atoms.

Many organisms modify their physiological functions by acclimating to changes in their environment. Recent studies of thermal physiology have been influenced by verbal models that fail to consider the selective advantage of acclimation and thus make no predictions about variation in acclimation capacity. We used a quantitative model of optimal plasticity to generate predictions about the capacity of Drosophila melanogaster to acclimate to developmental temperature. This model predicts that the ability to acclimate thermal sensitivity should evolve when temperature varies greatly among generations. Based on the model, we expected that flies from the highly seasonal environment of New Jersey would acclimate thermal sensitivity more than would flies from the less seasonal environment of Florida. When raised at constant and fluctuating temperatures, flies from these populations failed to adjust their thermal optima in the way predicted by the model, suggesting that current assumptions about functional and genetic constraints should be reconsidered.

Sodium benzyl penicillin, procaine penicillin and benethamine penicillin were applied into the bovine conjunctival sac as an aqueous solution or in ointment form in order to study the concentration-time profiles. The series of treatments was repeated in five animals in a random sequence. Penicillin concentration in conjunctival sac fluid (CF) was determined using the agar-well-diffusion assay technique. The data obtained were transformed to linear regression slopes. Similarity of the slopes within treatments (in five different eyes) enabled the construction of four common lines by co-variance analysis to represent each treatment. The regression coefficients of the four common lines were then compared to study the difference between treatments. Topical application of 5,000 iu sodium benzylpenicillin in aqueous solution at a concentration isotonic with 0.9% saline, produced a duration of therapeutic concentration (DTC) in CF of 12.6 +/- 1.5 h. When the same salt or other less water-soluble ones were formulated at the same concentration in an ointment base, the DTC was significantly prolonged. For all treatments, peak concentrations in CF were recorded at the first sampling and ranged between 7 iu/ml and 14 iu/ml. Sodium benzylpenicillin or procaine penicillin, both in the ointment base, produced DTCs of 38.8 +/- 2.1 h and 37 +/- 4.0 h, respectively, while the ointment formulation of benethamine penicillin produced a DTC of 56 +/- 4.5 h. The prolonged duration observed in the eye ointments can be partly accounted for by the viscous nature of the base. Other differences may be dependent on relative water solubility of each penicillin product and complexity of the surface mucosae of the eye.

Single dose, subconjunctival injections of procaine penicillin using either skin or conjunctival routes of administration were evaluated in order to compare the duration of antibacterial concentrations at the site of Moraxella bovis infection. Samples of conjunctival sac fluid (CF) were collected using blunted capillary tubes and were periodically assayed for penicillin by an agar-well-diffusion technique. Linear regression lines were constructed for concentration of penicillin-time profiles. Similarity of the regression slopes for each treatment enabled the construction of three common lines by the method of co-variance analysis in order to represent each treatment. Treatments were thereafter compared by the slopes of the common regression lines. A subconjunctival injection of procaine penicillin at a dose of 6 X 10(5) iu in 2 ml, administered either through the skin or through the conjunctiva, produced a peak penicillin concentration in the CF of approximately 8 iu/ml for either route and a duration of therapeutic concentration (DTC) of 67.6 +/- 4.9 and 40 +/- 2.7 h respectively. A dose of 3 X 10(5) iu in 1 ml, administered through the conjunctiva, produced a similar peak but the DTC was reduced to 35 +/- 4.2 h. The results of this study support field practices, as adequate penicillin concentrations were maintained by both techniques investigated.