Approaching Mechanization of Plant Micropropagation

Investigations of materials and methods for growing plant tissue in a continual-flow, liquid nutrient medium as an alternative to semisolid agar medium have been made. Enhanced growth of plant tissue on microporouspolypropylene membranes floating on a liquid nutrient has been demonstrated. Moreover, in vitro plantlets on the microporous membrane are free from entanglement with the support matrix and readily available to mechanizedhandling. Trained growth of plantlets through polypropylene netting shows potential for mechanization by mass handling (separation, singulation, and transfer) of plant tissue cultures

Multi-channel electronic and vibrational dynamics in polyatomic resonant high-order harmonic generation

High-order harmonic generation in polyatomic molecules generally involves multiple channels of ionization. Their relative contribution can be strongly influenced by the presence of resonances, whose assignment remains a major challenge for high-harmonic spectroscopy. Here we present a multi-modal approach for the investigation of unaligned polyatomic molecules, using SF6 as an example. We combine methods from extreme-ultraviolet spectroscopy, above-threshold ionization and attosecond metrology. Fragment-resolved above-threshold ionization measurements reveal that strong-field ionization opens at least three channels. A shape resonance in one of them is found to dominate the signal in the 20-26 eV range. This resonance induces a phase jump in the harmonic emission, a switch in the polarization state and different dynamical responses to molecular vibrations. This study demonstrates a method for extending high-harmonic spectroscopy to polyatomic molecules, where complex attosecond dynamics are expected

Assessment of cognitive self-statements during marital problem solving: A comparison of two methods

Twenty maritally distressed couples (DC) and 20 nondistressed couples (NDC) were recruited and asked to undertake 10 minutes of problem-solving discussions, which were videotaped. Each individual partner’s cognitive self-statements during the interaction were assessed using two methods: video-assisted recall (VR) and thought listing (TL). Reported cognitions from each method were content- analysed and classified into five categories: partner- referent positive, partner- referent negative, self-referent positive, self- referent negative, and other. Proportions of reported cognitions falling into each category were analysed in two separate two-way MANOVAs (marital distress/ nondistress x sex) for the VR and TL measures. Results of each MANOVA indicated a highly significant effect of marital distress on cognitions, and a significant effect of sex on the VR but not the TL measure. Discriminant analyses showed that the VR and TL methods both discriminated between DC and NDC groups. Post hoc univariate ANOVAs indicated that DC had significantly higher proportions of negative partner- referent cognitions, and lower proportions of positive partner- referent cognitions, than NDC while problem solving. The relative merits of each cognitive assessment method, and their potential use in increasing marital therapy effectiveness, are discussed

Genotyping Validates the Efficacy of Photographic Identification in a Capture-Mark-Recapture Study Based on the Head Scale Patterns of the Prairie Lizard (\u3ci\u3eSceloporus consobrinus\u3c/i\u3e)

Population studies often incorporate capture‐mark‐recapture (CMR) techniques to gather information on long‐term biological and demographic characteristics. A fundamental requirement for CMR studies is that an individual must be uniquely and permanently marked to ensure reliable reidentification throughout its lifespan. Photographic identification involving automated photographic identification software has become a popular and efficient noninvasive method for identifying individuals based on natural markings. However, few studies have (a) robustly assessed the performance of automated programs by using a double‐marking system or (b) determined their efficacy for long‐term studies by incorporating multi‐year data. Here, we evaluated the performance of the program Interactive Individual Identification System (I3S) by cross‐validating photographic identifications based on the head scale pattern of the prairie lizard (Sceloporus consobrinus) with individual microsatellite genotyping (N = 863). Further, we assessed the efficacy of the program to identify individuals over time by comparing error rates between within‐year and between‐year recaptures. Recaptured lizards were correctly identified by I3S in 94.1% of cases. We estimated a false rejection rate (FRR) of 5.9% and a false acceptance rate (FAR) of 0%. By using I3S, we correctly identified 97.8% of within‐year recaptures (FRR = 2.2%; FAR = 0%) and 91.1% of between‐year recaptures (FRR = 8.9%; FAR = 0%). Misidentifications were primarily due to poor photograph quality (N = 4). However, two misidentifications were caused by indistinct scale configuration due to scale damage (N = 1) and ontogenetic changes in head scalation between capture events (N = 1). We conclude that automated photographic identification based on head scale patterns is a reliable and accurate method for identifying individuals over time. Because many lizard or reptilian species possess variable head squamation, this method has potential for successful application in many species

Control system for ion Penning traps at the AEgIS experiment at CERN

The AEgIS experiment located at the Antiproton Decelerator at CERN aims to measure the gravitational fall of a cold antihydrogen pulsed beam. The precise observation of the antiatoms in the Earth gravitational field requires a controlled production and manipulation of antihydrogen. The neutral antimatter is obtained via a charge exchange reaction between a cold plasma of antiprotons from ELENA decelerator and a pulse of Rydberg positronium atoms. The current custom electronics designed to operate the 5 and 1 T Penning traps are going to be replaced by a control system based on the ARTIQ & Sinara open hardware and software ecosystem. This solution is present in many atomic, molecular and optical physics experiments and devices such as quantum computers. We report the status of the implementation as well as the main features of the new control system

Development of a detector for inertial sensing of positronium at AEgIS (CERN)

The primary goal of the AEgIS collaboration at CERN is to measure the gravitational acceleration on neutral antimatter. Positronium (Ps), the bound state of an electron and a positron, is a suitable candidate for a force-sensitive inertial measurement by means of deflectometry/interferometry. In order to conduct such an experiment, the impact position and time of arrival of Ps atoms at the detector must be detected simultaneously. The detection of a low-velocity Ps beam with a spatial resolution of (88 ± 5) μm was previously demonstrated [1]. Based on the methodology employed in [1] and [2], a hybrid imaging/timing detector with increased spatial resolution of about 10 μm was developed. The performance of a prototype was tested with a positron beam. The concept of the detector and first results are presented

High-resolution MCP-TimePix3 imaging/timing detector for antimatter physics

We present a hybrid imaging/timing detector for force sensitive inertial measurements designed for measurements on positronium, the metastable bound state of an electron and a positron, but also suitable for applications involving other low intensity, low energy beams of neutral (antimatter)-atoms, such as antihydrogen. The performance of the prototype detector was evaluated with a tunable low energy positron beam, resulting in a spatial resolution of approximate t

Positronium laser cooling via the 13S1^3S-23P2^3P transition with a broadband laser pulse

We report on laser cooling of a large fraction of positronium (Ps) in free-flight by strongly saturating the $1^3S$-$2^3P$ transition with a broadband, long-pulsed 243 nm alexandrite laser. The ground state Ps cloud is produced in a magnetic and electric field-free environment. We observe two different laser-induced effects. The first effect is an increase in the number of atoms in the ground state after the time Ps has spent in the long-lived $3^3P$ states. The second effect is the one-dimensional Doppler cooling of Ps, reducing the cloud's temperature from 380(20) K to 170(20) K. We demonstrate a 58(9) % increase in the coldest fraction of the Ps ensemble.Comment: 6 pages, 5 figure

Hybrid imaging and timing ps laser excitation diagnostics for pulsed antihydrogen production

open48siIn this work we present a hybrid detection method providing simultaneous imaging and timing information suitable for fully monitoring positronium (Ps) formation, its laser excitation, and its spatial propagation for the first trials of pulsed antihydrogen (H) production through a charge-exchange reaction with trapped antiprotons (p). This combined method, based on the synchronous acquisition of an EJ-200 scintillation detector and a microchannel plate (MCP) detector with a dual readout (phosphor screen image and electrical pick-up signal), allows all relevant events in the experiment to be accurately determined in time while allowing high resolution images of e+ from Ps laser photodissociations to be acquired. The timing calibration process of the two detectors discussed in details as well as the future perspectives opened by this method.openCaravita R.; Antonello M.; Belov A.; Bonomi G.; Brusa R.S.; Caccia M.; Camper A.; Castelli F.; Comparat D.; Consolati G.; Demetrio A.; Di Noto L.; Doser M.; Fani M.; Ferragut R.; Gerber S.; Giammarchi M.; Gligorova A.; Gloggler L.T.; Guatieri F.; Haider S.; Hinterberger A.; Khalidova O.; Krasnicky D.; Lagomarsino V.; Malbrunot C.; Mariazzi S.; Matveev V.; Muller S.R.; Nebbia G.; Nedelec P.; Oberthaler M.; Oswald E.; Pagano D.; Penasa L.; Petracek V.; Prelz F.; Rienacker B.; Rohne O.M.; Rotondi A.; Sandaker H.; Santoro R.; Testera G.; Tietje I.; Toso V.; Wolz T.; Zimmer C.; Zurlo N.Caravita, R.; Antonello, M.; Belov, A.; Bonomi, G.; Brusa, R. S.; Caccia, M.; Camper, A.; Castelli, F.; Comparat, D.; Consolati, G.; Demetrio, A.; Di Noto, L.; Doser, M.; Fani, M.; Ferragut, R.; Gerber, S.; Giammarchi, M.; Gligorova, A.; Gloggler, L. T.; Guatieri, F.; Haider, S.; Hinterberger, A.; Khalidova, O.; Krasnicky, D.; Lagomarsino, V.; Malbrunot, C.; Mariazzi, S.; Matveev, V.; Muller, S. R.; Nebbia, G.; Nedelec, P.; Oberthaler, M.; Oswald, E.; Pagano, D.; Penasa, L.; Petracek, V.; Prelz, F.; Rienacker, B.; Rohne, O. M.; Rotondi, A.; Sandaker, H.; Santoro, R.; Testera, G.; Tietje, I.; Toso, V.; Wolz, T.; Zimmer, C.; Zurlo, N