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A dense plasma focus (DPF) is a relatively compact coaxial plasma gun, which completes its discharge as a Z-pinch. These devices are designed to operate at a variety of scales to produce short (

For more than 225 million y, all seed plants were woody trees, shrubs, or vines. Shortly after the origin of angiosperms ∼140 million y ago (MYA), the Nymphaeales (water lilies) became one of the first lineages to deviate from their ancestral, woody habit by losing the vascular cambium, the meristematic population of cells that produces secondary xylem (wood) and phloem. Many of the genes and gene families that regulate differentiation of secondary tissues also regulate the differentiation of primary xylem and phloem, which are produced by apical meristems and retained in nearly all seed plants. Here, we sequenced and assembled a draft genome of the water lily Nymphaea thermarum , an emerging system for the study of early flowering plant evolution, and compared it to genomes from other cambium-bearing and cambium-less lineages (e.g., monocots and Nelumbo ). This revealed lineage-specific patterns of gene loss and divergence. Nymphaea is characterized by a significant contraction of the HD-ZIP III transcription factors, specifically loss of REVOLUTA , which influences cambial activity in other angiosperms. We also found the Nymphaea and monocot copies of cambium-associated CLE signaling peptides display unique substitutions at otherwise highly conserved amino acids. Nelumbo displays no obvious divergence in cambium-associated genes. The divergent genomic signatures of convergent loss of vascular cambium reveals that even pleiotropic genes can exhibit unique divergence patterns in association with independent events of trait loss. Our results shed light on the evolution of herbaceousness—one of the key biological innovations associated with the earliest phases of angiosperm evolution.

Although the ultimate purpose of a seed is the successful establishment of the next generation, seed development involves more than embryo growth. In angiosperms, seed development requires the intimate coordination of three distinct entities — maternal tissue and two offspring, embryo and embryo-nourishing endosperm. Although seeds are cornerstones of many terrestrial ecosystems and human diets, we are only beginning to understand the interactions among seed tissues and the molecular processes and genes that determine them. Recent studies of gene expression and function in distantly related angiosperms, combined with over 100 years of embryological research, have repeatedly highlighted the endosperm associated with maternal-filial boundaries as a central point in seed developmental dynamics. In this review, we highlight evidence that links this zone with nutritional dynamics, developmental signaling, and imprinted gene expression. We suggest that the underappreciated diversity of this specialized endosperm across angiosperms deserves further study from developmental, molecular, and genetic perspectives.

A dense plasma focus (DPF) is a compact coaxial plasma gun, which completes its discharge as a Z-pinch, producing short (11 neutrons/pulse at 3.3 MA peak current, and higher-current commissioning is under way. Like most DPFs, MJOLNIR exhibits variable yields in some configurations. We present evidence of the role of parasitic current paths within the gun in stochastically influencing the yield. First through “conditioning shots,” where new hardware has been introduced, we show that increased run-down and run-in speeds correlate with higher yields. These observations are consistent with current being delivered to the electrodes but not to the main plasma sheath, degrading the implosion-driving force. Once nominal conditions are established, we correlate low-performing discharges with smaller current dip and associated voltage spike for a fixed machine configuration. A snow-plow model is able to recreate small-magnitude current dips through the introduction of a parasitic current path, and particle-in-cell simulations establish how parasitic current paths lower the ion beam energy available to produce neutrons. Finally, we observe an increased likelihood of shots with low yield and smaller current dip with increasing fill pressure.

The first record of gene expression during seed development within the Nymphaeales provides evidence for a variety of biological processes, including dynamic epigenetic patterning during sexual reproduction in the water lily Nymphaea thermarum. Studies of gene expression during seed development have been performed for a growing collection of species from a phylogenetically broad sampling of flowering plants (angiosperms). However, angiosperm lineages whose origins predate the divergence of monocots and eudicots have been largely overlooked. In order to provide a new resource for understanding the early evolution of seed development in flowering plants, we sequenced transcriptomes of whole ovules and seeds from three key stages of reproductive development in the waterlily Nymphaea thermarum, an experimentally tractable member of the Nymphaeales. We first explore patterns of gene expression, beginning with mature ovules and continuing through fertilization into early- and mid-stages of seed development. We find patterns of gene expression that corroborate histological/morphological observations of seed development in this species, such as expression of genes involved in starch synthesis and transcription factors that have been associated with embryo and endosperm development in other species. We also find evidence for processes that were previously not known to be occurring during seed development in this species, such as epigenetic modification. We then examine the expression of genes associated with patterning DNA and histone methylation-processes that are essential for seed development in distantly related and structurally diverse monocots and eudicots. Around 89% of transcripts putatively homologous to DNA and histone methylation modifiers are expressed during seed development in N. thermarum, including homologs of genes known to pattern imprinting-related epigenetic modifications. Our results suggest that dynamic epigenetic patterning is a deeply conserved aspect of angiosperm seed development.

Studies of gene expression during seed development have been performed for a growing collection of species from a phylogenetically broad sampling of flowering plants (angiosperms). However, attention has mostly been focused on crop species or a small number of ‘model’ systems. Information on gene expression during seed development is minimal for those angiosperm lineages whose origins predate the divergence of monocots and eudicots. In order to provide a new perspective on the early evolution of seed development in flowering plants, we sequenced transcriptomes of whole ovules and seeds from three key stages of reproductive development in the waterlily Nymphaea thermarum, an experimentally-tractable member of the Nymphaeales. We first explore general patterns of gene expression, beginning with mature ovules and continuing through fertilization into early- and mid-seed development. We then examine the expression of genes associated with DNA and histone methylation – processes known to be essential for development in distantly-related and structurally-divergent monocots and eudicots. Around 60% of transcripts putatively homologous to DNA and histone methylation modifiers are differentially expressed during seed development in N. thermarum, suggesting that the importance of dynamic epigenetic patterning during seed development dates to the earliest phases of angiosperm evolution. However, genes involved in establishing, maintaining, and removing methylation marks associated with genetic imprinting show a mix of conserved and unique expression patterns between N. thermarum and other flowering plants. Our data suggests that the regulation of imprinting has likely changed throughout angiosperm evolution, and furthermore identifies genes that merit further characterization in any angiosperm system.

Seeds are a key life cycle stage for many plants. Seeds are also the basis of agriculture and the primary source of calories consumed by humans1. Here, we employ single-nucleus RNA-sequencing to generate a transcriptional atlas of developing Arabidopsis thaliana seeds, with a focus on endosperm. Endosperm, the primary site of gene imprinting in flowering plants, mediates the relationship between the maternal parent and the embryo2. We identify transcriptionally uncharacterized nuclei types in the chalazal endosperm, which interfaces with maternal tissue for nutrient unloading3,4. We demonstrate that the extent of parental bias of maternally expressed imprinted genes varies with cell-cycle phase, and that imprinting of paternally expressed imprinted genes is strongest in chalazal endosperm. Thus, imprinting is spatially and temporally heterogeneous. Increased paternal expression in the chalazal region suggests that parental conflict, which is proposed to drive imprinting evolution, is fiercest at the boundary between filial and maternal tissues. This study generated a transcriptional atlas of developing Arabidopsis seeds with single-nucleus RNA-sequencing, reporting transcriptionally uncharacterized nuclei types in the chalazal endosperm and spatially and temporally heterogenous imprinting in the seeds.

Seeds are the basis of agriculture, yet their full transcriptional complexity has remained unknown. Here, we employ single-nucleus RNA-sequencing to characterize developing Arabidopsis thaliana seeds, with a focus on endosperm. Endosperm, the site of gene imprinting in plants, mediates the relationship between the maternal parent and embryo. We identify new cell types in the chalazal endosperm region, which interfaces with maternal tissue for nutrient unloading. We further demonstrate that the extent of parental bias of maternally expressed imprinted genes varies with cell cycle phase, and that imprinting of paternally expressed imprinted genes is strongest in chalazal endosperm. These data indicate imprinting in endosperm is heterogeneous and suggest that parental conflict, which is proposed to drive the evolution of imprinting, is fiercest at the boundary between filial and maternal tissues.

For more than 225 million y, all seed plants were woody trees, shrubs, or vines. Shortly after the origin of angiosperms ∼140 million y ago (MYA), the Nymphaeales (water lilies) became one of the first lineages to deviate from their ancestral, woody habit by losing the vascular cambium, the meristematic population of cells that produces secondary xylem (wood) and phloem. Many of the genes and gene families that regulate differentiation of secondary tissues also regulate the differentiation of primary xylem and phloem, which are produced by apical meristems and retained in nearly all seed plants. Here, we sequenced and assembled a draft genome of the water lily

* Doutora em Educação pela Universidade Federal de Sergipe com estágio de doutorado sanduíche no Istituto Universitario Sophia, Itália (2012). Professora das Faculdades Integradas de Sergipe - FISE e da Faculdade Jardins (2014). Membro da Sociedade Brasileira de História da Educação.** Doutora em Teologia Dogmática pela Pontificia Università Lateranense, Roma. Professora do Istituto UniversitarioUSophia. Coordenadora do Programa de Doutorado em Pesquisa Transdisciplinar "Fondamenti e Prospettive di una Cultura dell'Unità ", Istituto Universitario Sophia."Escrever-te-ei sem demora"! O epistolario de Chiara Lubich: estratégias e práticasResumo: Este artigo ressalta o debate acerca dos usos das correspondências como fonte para os estudos de História da Educação e, sobretudo, da História da Educação religiosa católica. Chiara Lubich, professora italiana, adotou as cartas como um recurso de formação capaz de chegar a pessoas e lugares onde não poderia estar fisicamente e, ao longo de sua vida, criou uma abordagem educativa por meio epistolar que, pela notoriedade em âmbito religioso e social, pode ser considerada uma perspectiva diferenciada de pedagogia católica. O estudo visa identificar por meio da análise de um de seus epistolários, o enfoque pedagógico contido em seus escritos. A reflexão apresenta como subsídios teóricos os conceitos de materialidade de Roger Chartier; carisma, campo religioso e relações simbólicas de Pierre Bourdieu, além de estratégia e tática de Michel de Certeau.Palavras-chave: Correspondências. Chiara Lubich. Pedagogia. História da Educação."I will write immediately"! The Chiara Lubich's epitolary: strategies and practicesAbstract: This article emphasizes the debate about the use of written correspondence as a source for the study of the History of Education and especially the history of Catholic religious education. Chiara Lubich, an Italian Catholic school teacher who, used letters as a privileged way to keep in touch with the people. She took letters as a resource able to reach people and places where she could not be physically present and, created an educational approach epistolary, who can be considered as a different perspective in Catholic pedagogy. The research aims to identify and analyze how Chiara's teaching activity through epistolary medium was configured and, specifically, what formative approach is contained in these writings. The theoretical foundation of the research is based on the concepts of materiality, by Roger Chartier; charisma, religious field and symbolic relations of Pierre Bourdieu; in addition, Michel de Certeau's strategy and tactic were used.Keywords: Chiara Lubich. Correspondence. History of Education. Pedagogy."Ti scriverò presto"! Lo epistolà rio di Chiara Lubich: strategia e praticheSommario:Obiettivo di questo lavoro è l'analisi della valenza formativa della scrittura epistolare nella storia dell'educazione, soprattutto nella storia dell'educazione cattolica. Chiara Lubich, un'insegnante italiana, ha utilizzato la "corrispondenza" come "metodo" di formazione e "mezzo" privilegiato per raggiungere e rimanere in contatto con le persone anche in luoghi in cui non poteva essere fisicamente presente. L'epistolario di Chiara, anche per la sua notorietà in ambito religioso e sociale, può essere considerato come un particolare approccio educativo nell'ambito della pedagogia Cattolica. Lo studio si propone di individuare attraverso l'analisi di uno dei suoi epistolari, l'approccio pedagogico contenute nei suoi scritti. La riflessione presenta come supporto teorico i concetti di materialità di Roger Chartier; carisma, campo religioso e relazioni simboliche di Pierre Bourdieu; strategia e tattica di Michel de Certeau.Parole chiave: Chiara Lubich. Pedagogia. Scrittura epistolare. Storia dell Educazione.Data de registro: 17/11/2015Data de aceite: 18/01/2016Referências:ANNUARIO della R. Scuola Complementare "N. E p.Bronzetti" di Trento. Per l'anno scolastico 1927-1928. Anno VI dell'era fascista. Trento: Tipografia - Libreria Ed. G. B. Monauni, 1928.ANNUARIO della R. Scuola di avviamento al lavoro "N. E p.Bronzetti" classe I e della R. Scuola Complementare classe II e III di Trento. Per l'anno scolastico 1929-1930. Anno VIII dell'era fascista. Trento: Tipografi a artiglianelli, 1930.AGUIAR, Thiago Borges. Jan Hus: As cartas de um educador e seu legado imortal. 305f. 2010. Tese (Doutorado em Educação) - Faculdade de Educação da Universidade de São Paulo, Universidade de São Paulo, São Paulo, 2010.ALMEIDA NETO, Dionísio de. Pelo império da virtude - formação, saberes e práticas de Dom Domingos Quirino de Souza (1813-1863). Aracaju: Gráfica e Editora Triunfo Ltda, 2007.ANDRADE JUNIOR, Péricles Morais de. Sob o olhar diligente do pastor: a Igreja Católica em Sergipe (1831-1926). 2000. Dissertação (Mestrado em Educação) - Faculdade de Educação, Universidade Federal de Sergipe, São Cristóvão, 2000.BIBLIA SAGRADA. Tradução: Centro Bíblico Católico. 31ed. São Paulo: Ave Maria, 1981.BOLONHA, Hugo de. Rationes dictandi. In: TIN, Emerson (Org.). A arte de escrever cartas: Anônimo de Bolonha, Erasmo de Rotterdam, Justo Lípsio. 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Supplementary Information

To examine the association of an automated physician feedback system prompting physician review of early readmissions with a change in overall readmission rates.The University of Utah Internal Medicine Hospitalist Service created an automated system to alert discharging providers to any patient readmitted within 30 days. For any 7-day readmission, the physician was asked to complete a survey to describe the admission and discharge and to identify contributing factors to the readmission. Using the University HealthSystem Consortium database, readmission rates were compared prior to and following this intervention.Following the intervention, 30-day readmission rates significantly decreased from 13.93% to 11.99% (p = 0.0298). The 7-day readmission rates decreased as well but the findings were not statistically significant. The discharging physician deemed 45% of the readmissions preventable or probably preventable.Readmissions are common, costly and potentially preventable. This tool for physician audit and feedback and identification of defects contributing to readmissions was associated with a statistically significant decrease in 30-day readmissions. Further investigation is needed to verify these results and evaluate the best mechanism of application.

Theoretical and empirical studies have long connected the evolutionary innovation of endosperm, a genetically biparental product of a double fertilization process unique to flowering plants (angiosperms), to conflicting parental interests over offspring provisioning. Yet, none of these studies examined interparental conflict in representatives of any of the most ancient angiosperm lineages. We performed reciprocal interploidy crosses in the water lilyNymphaea thermarum, a member of one of the most ancient angiosperm lineages, Nymphaeales. We find that an excess of paternal genomes is associated with an increase in endosperm growth. By contrast, maternal ploidy negatively influences development or growth of all seed components, regardless of paternal genome dosage. Most relevant to the conflict over distribution of maternal resources, however, is that growth of the perisperm (seed storage tissue derived from the maternal sporophyte, found in all Nymphaeales) is unaffected by paternal genome dosage—ensuring maternal control of maternal resources. We conclude that the evolutionary transfer of embryo-nourishing function from a genetically biparental endosperm to a genetically maternal perisperm can be viewed as an effective maternal strategy to recapture control of resource distribution among progeny, and thus that interparental conflict has influenced the evolution of seed development in this ancient angiosperm lineage.

The dense plasma focus (DPF) is a z-pinch device that starts as a coaxial plasma railgun and ends in an implosion phase. DPF's historically were developed as thermonuclear devices. When used with deuterium and tritium gases a DPF can be used to produce neutrons; however, in operation, DPF's often suffered from inconsistent behavior, and the mechanisms driving the neutron production were poorly understood. Using kinetic modeling techniques recently developed at LLNL, we have gained insight into the mechanisms that lead to particle acceleration in the pinch region and can make informed design decisions for optimizing DPF behavior, from sub-kilojoule to mega-joule scale devices. Experimental DPF platforms at LLNL also serve to validate the behaviors seen in simulations and improve device performance with a view towards increased neutron generation, enhanced reproducibility, and decreased size and energy requirements.

Experiments were performed to maximize the neutron yield from a 2 kJ dense plasma focus (DPF) and characterize the amount of copper sputtered from the surface of an anode by varying the diameter of the anodes’ on-axis hollow. The hollow is a void in the copper material along the longitudinal axis of the anode. All the anodes had an outer diameter of 1.2 in. and the diameter of the hollow varied from 0 in. (no hollow) to 1 in. The anodes with a hollow produced a greater number of neutrons per discharge than the anode without a hollow. Over 40 discharges, the hollow anode that yielded the most neutrons (9.1 ±0.4 ×10 6 neutrons per discharge produced with the 0.75 in. hollow) produced >6 times more neutrons than the anode with no hollow. A qualitative observation of the anodes after 130 discharges showed less surface damage on anodes with a larger hollow. Quantitative sputter measurements were performed by characterizing the amount of copper sputtered onto on-axis quartz targets for three newly machined anodes, each with a particular hollow diameter. The quantitative results matched the qualitative observations: the copper sputter was reduced using larger hollows. The largest hollow sputtered 17 ±1.0 nm/sr/discharge of copper, a reduction of 69 % compared to the anode with the most damage.Experiments were performed to maximize the neutron yield from a 2 kJ dense plasma focus (DPF) and characterize the amount of copper sputtered from the surface of an anode by varying the diameter of the anodes’ on-axis hollow. The hollow is a void in the copper material along the longitudinal axis of the anode. All the anodes had an outer diameter of 1.2 in. and the diameter of the hollow varied from 0 in. (no hollow) to 1 in. The anodes with a hollow produced a greater number of neutrons per discharge than the anode without a hollow. Over 40 discharges, the hollow anode that yielded the most neutrons (9.1 ±0.4 ×10 6 neutrons per discharge produced with the 0.75 in. hollow) produced >6 times more neutrons than the anode with no hollow. A qualitative observation of the anodes after 130 discharges showed less surface damage on anodes with a larger hollow. Quantitative sputter measurements were performed by characterizing the amount of copper sputtered onto on-axis quartz targets for three newly machined ano...

Magnetically trapped antihydrogen atoms at low temperatures were used to test the charge neutrality of this antiatomic system, by precisely placing a limit to its electrical charge. A new method for measuring the gravitational interaction of antimatter was also developed, and prospects for making a precise measurement of this interaction are discussed. Finally, progress towards a precise, direct test of CPT symmetry by laser spectroscopy of antihydrogen is presented.

The ALPHA project is an international collaboration, based at CERN, with the experimental goal of performing precision spectroscopic measurements on antihydrogen. As part of this endeavor, the ALPHA experiment includes a silicon tracking detector. This detector consists of a three-layer array of silicon modules surrounding the antihydrogen trapping region of the ALPHA apparatus. Using this device, the antihydrogen annihilation position can be determined with a spatial resolution of better than 5 mm. Knowledge of the annihilation distribution was a critical component in the recently successful antihydrogen trapping effort. This paper will describe the methods used to reconstruct annihilation events in the ALPHA detector. Particular attention will be given to the description of the background rejection criteria.

Precision comparisons of hyperfine intervals in atomic hydrogen and antihydrogen are expected to yield experimental tests of the CPT theorem. The CERN-based ALPHA collaboration has initiated a program of study focused on microwave spectroscopy of trapped ground-state antihydrogen atoms. This paper outlines some of the proposed experiments, and summarizes measurements that characterize microwave fields that have been injected into the ALPHA apparatus.

Precision spectroscopic comparison of hydrogen and antihydrogen holds the promise of a sensitive test of the Charge-Parity-Time theorem and matter-antimatter equivalence. The clearest path towards realising this goal is to hold a sample of antihydrogen in an atomic trap for interrogation by electromagnetic radiation. Achieving this poses a huge experimental challenge, as state-of-the-art magnetic-minimum atom traps have well depths of only ∼1 T (∼0.5 K for ground state antihydrogen atoms). The atoms annihilate on contact with matter and must be ‘born’ inside the magnetic trap with low kinetic energies. At the ALPHA experiment, antihydrogen atoms are produced from antiprotons and positrons stored in the form of non-neutral plasmas, where the typical electrostatic potential energy per particle is on the order of electronvolts, more than 104 times the maximum trappable kinetic energy. In November 2010, ALPHA published the observation of 38 antiproton annihilations due to antihydrogen atoms that had been trapped for at least 172 ms and then released—the first instance of a purely antimatter atomic system confined for any length of time (Andresen et al., Nature 468:673, 2010). We present a description of the main components of the ALPHA traps and detectors that were key to realising this result. We discuss how the antihydrogen atoms were identified and how they were discriminated from the background processes. Since the results published in Andresen et al. (Nature 468:673, 2010), refinements in the antihydrogen production technique have allowed many more antihydrogen atoms to be trapped, and held for much longer times. We have identified antihydrogen atoms that have been trapped for at least 1,000 s in the apparatus (Andresen et al., Nature Physics 7:558, 2011). This is more than sufficient time to interrogate the atoms spectroscopically, as well as to ensure that they have relaxed to their ground state.

In efforts to trap antihydrogen, a key problem is the vast disparity between the neutral trap energy scale (\(\sim\!50\,\upmu\mathrm{eV}\)), and the energy scales associated with plasma confinement and space charge (~1 eV). In order to merge charged particle species for direct recombination, the larger energy scale must be overcome in a manner that minimizes the initial antihydrogen kinetic energy. This issue motivated the development of a novel injection technique utilizing the inherent nonlinear nature of particle oscillations in our traps. We demonstrated controllable excitation of the center-of-mass longitudinal motion of a thermal antiproton plasma using a swept-frequency autoresonant drive. When the plasma is cold, dense and highly collective in nature, we observe that the entire system behaves as a single-particle nonlinear oscillator, as predicted by a recent theory. In contrast, only a fraction of the antiprotons in a warm or tenuous plasma can be similarly excited. Antihydrogen was produced and trapped by using this technique to drive antiprotons into a positron plasma, thereby initiating atomic recombination. The nature of this injection overcomes some of the difficulties associated with matching the energies of the charged species used to produce antihydrogen.

Spectroscopy of antihydrogen has the potential to yield high-precision tests of the CPT theorem and shed light on the matter-antimatter imbalance in the Universe. The ALPHA antihydrogen trap at CERN's Antiproton Decelerator aims to prepare a sample of antihydrogen atoms confined in an octupole-based Ioffe trap and to measure the frequency of several atomic transitions. We describe our techniques to directly measure the antiproton temperature and a new technique to cool them to below 10 K. We also show how our unique position-sensitive annihilation detector provides us with a highly sensitive method of identifying antiproton annihilations and effectively rejecting the cosmic-ray background., 10 pages, 5 figures

Antihydrogen spectroscopy promises precise tests of the symmetry of matter and antimatter, and can possibly offer new insights into the baryon asymmetry of the universe. Antihydrogen is, however, difficult to synthesize and is produced only in small quantities. The ALPHA collaboration is therefore pursuing a path towards trapping cold antihydrogen to permit the use of precision atomic physics tools to carry out comparisons of antihydrogen and hydrogen. ALPHA has addressed these challenges. Control of the plasma sizes has helped to lower the influence of the multipole field used in the neutral atom trap, and thus lowered the temperature of the created atoms. Finally, the first systematic attempt to identify trapped antihydrogen in our system is discussed. This discussion includes special techniques for fast release of the trapped anti-atoms, as well as a silicon vertex detector to identify antiproton annihilations. The silicon detector reduces the background of annihilations, including background from antiprotons that can be mirror trapped in the fields of the neutral atom trap. A description of how to differentiate between these events and those resulting from trapped antihydrogen atoms is also included.

Antihydrogen production in a neutral atom trap formed by an octupole-based magnetic field minimum is demonstrated using field-ionization of weakly bound anti-atoms. Using our unique annihilation imaging detector, we correlate antihydrogen detection by imaging and by field-ionization for the first time. We further establish how field-ionization causes radial redistribution of the antiprotons during antihydrogen formation and use this effect for the first simultaneous measurements of strongly and weakly bound antihydrogen atoms. Distinguishing between these provides critical information needed in the process of optimizing for trappable antihydrogen. These observations are of crucial importance to the ultimate goal of performing CPT tests involving antihydrogen, which likely depends upon trapping the anti-atom. Antihydrogen production in a neutral atom trap formed by an octupole-based magnetic field minimum is demonstrated using field-ionization of weakly bound anti-atoms. Using our unique annihilation imaging detector, we correlate antihydrogen detection by imaging and by field-ionization for the first time. We further establish how field-ionization causes radial redistribution of the antiprotons during antihydrogen formation and use this effect for the first simultaneous measurements of strongly and weakly bound antihydrogen atoms. Distinguishing between these provides critical information needed in the process of optimizing for trappable antihydrogen. These observations are of crucial importance to the ultimate goal of performing CPT tests involving antihydrogen, which likely depends upon trapping the anti-atom.

The goal of the ALPHA collaboration at CERN is to test CPT conservation by comparing the 1S–2S transitions of hydrogen and antihydrogen. To reach the ultimate accuracy of 1 part in 10 18 , the (anti)atoms must be trapped. Using current technology, only magnetic minimum traps can confine (anti)hydrogen. In this paper, the design of the ALPHA antihydrogen trap and the results of measurements on a prototype system will be presented. The trap depth of the final system will be 1.16 T, corresponding to a temperature of 0.78 K for ground state antihydrogen.

BACKGROUND AND AIMS Nymphaea thermarum is a member of the Nymphaeales, of one of the most ancient lineages of flowering plants. This species was only recently described and then declared extinct in the wild, so little is known about its reproductive biology. In general, the complete ontogeny of ovules and seeds is not well documented among species of Nymphaea and has never been studied in the subgenus Brachyceras, the clade to which N. thermarum belongs. METHODS Flowers and fruits were processed for brightfield, epifluorescence and confocal microscopy. Flower morphology, with emphasis on the timing of male and female functions, was correlated with key developmental stages of the ovule and the female gametophyte. Development of the seed tissues and dynamics of polysaccharide reserves in the endosperm, perisperm and embryo were examined. KEY RESULTS Pollen release in N. thermarum starts before the flower opens. Cell walls of the micropylar nucellus show layering of callose and cellulose in a manner reminiscent of transfer cell wall patterning. Endosperm development is ab initio cellular, with micropylar and chalazal domains that embark on distinct developmental trajectories. The surrounding maternal perisperm occupies the majority of seed volume and accumulates starch centrifugally. In mature seeds, a minute but fully developed embryo is surrounded by a single, persistent layer of endosperm. CONCLUSIONS Early male and female function indicate that N. thermarum is predisposed towards self-pollination, a phenomenon that is likely to have evolved multiple times within Nymphaea. While formation of distinct micropylar and chalazal developmental domains in the endosperm, along with a copious perisperm, characterize the seeds of most members of the Nymphaeales, seed ontogenies vary between and among the constituent families. Floral biology, life history traits and small genome size make N. thermarum uniquely promising as an early-diverging angiosperm model system for genetic and molecular studies.

The properties of antihydrogen are expected to be identical to those of hydrogen, and any differences would constitute a profound challenge to the fundamental theories of physics. The most commonly discussed antiatom-based tests of these theories are searches for antihydrogen-hydrogen spectral differences (tests of CPT (charge-parity-time) invariance) or gravitational differences (tests of the weak equivalence principle). Here we, the ALPHA Collaboration, report a different and somewhat unusual test of CPT and of quantum anomaly cancellation. A retrospective analysis of the influence of electric fields on antihydrogen atoms released from the ALPHA trap finds a mean axial deflection of 4.1±3.4 mm for an average axial electric field of 0.51 V mm−1. Combined with extensive numerical modelling, this measurement leads to a bound on the charge Qe of antihydrogen of Q=(−1.3±1.1±0.4) × 10−8. Here, e is the unit charge, and the errors are from statistics and systematic effects., Fundamental theories do not predict a difference between the properties of matter and antimatter, but experimental tests of this are still in their infancy. To this end, this study analyses the effects of electric fields on antihydrogen atoms in the ALPHA trap to place a bound on the charge of antihydrogen.

The ALPHA collaboration, based at CERN, has recently succeeded in confining cold antihydrogen atoms in a magnetic minimum neutral atom trap and has performed the first study of a resonant transition of the anti-atoms. The ALPHA apparatus will be described herein, with emphasis on the structural aspects, diagnostic methods and techniques that have enabled antihydrogen trapping and experimentation to be achieved. © 2013 Elsevier B.V.

There has been a perennial return in the history of thought to the dialectic of the one and the many, and so the foundations of mathematics as developed through time could not but reflect this same dilemma. This article, as its point of departure, looks at the meaning of “one” in a few authors of Ancient and Scholastic thought. Then the author turns to the unique event of the Pact of unity between Chiara Lubich and Igino Giordani. She goes on from there to examine the abstract pattern of “oneness” which emerges, utilizing some of the categories offered by modern mathematics, from set theory to mereology. The One resulting from the Pact turns out to be a concept that has a rational underpinning, since the conceptual instruments for its formal description can be found in the foundations of mathematics. On the other hand, the author argues that familiarity with the structure of the One resulting from the Pact can be a significant factor in the development of a promising new axiomatic framework.

We describe the implementation of evaporative cooling of charged particles in the ALPHA apparatus. Forced evaporation has been applied to cold samples of antiprotons held in Malmberg-Penning traps. Temperatures on the order of 10 K were obtained, while retaining a significant fraction of the initial number of particles. We have developed a model for the evaporation process based on simple rate equations and applied it succesfully to the experimental data. We have also observed radial re-distribution of the clouds following evaporation, explained by simple conservation laws. We discuss the relevance of this technique for the recent demonstration of magnetic trapping of antihydrogen.

Over the last decades it has become routine to form beams of positrons and antiprotons and to use them to produce trapped samples of both species for a variety of purposes. Positrons can be captured efficiently, for instance using a buffer-gas system, and in such quantities to form dense, single component plasmas useful for antihydrogen formation. The latter is possible using developments of techniques for dynamically capturing and then cooling antiprotons ejected from the Antiproton Decelerator at CERN. The antiprotons can then be manipulated by cloud compression and evaporative cooling to form tailored plasmas. We will review recent advances that have allowed antihydrogen atoms to be confined for the first time in a shallow magnetic minimum neutral atom trap superimposed upon the region in which the antiparticles are held and mixed. A new mixing technique has been developed to help achieve this using autoresonant excitation of the centreofmass longitudinal motion of an antiproton cloud. This allows efficient antihydrogen formation without imparting excess energy to the antiprotons and helps enhance the probability of trapping the anti-atom.

Recently, antihydrogen atoms were trapped at CERN in a magnetic minimum (minimum-B) trap formed by superconducting octupole and mirror magnet coils. The trapped antiatoms were detected by rapidly turning off these magnets, thereby eliminating the magnetic minimum and releasing any antiatoms contained in the trap. Once released, these antiatoms quickly hit the trap wall, whereupon the positrons and antiprotons in the antiatoms annihilated. The antiproton annihilations produce easily detected signals; we used these signals to prove that we trapped antihydrogen. However, our technique could be confounded by mirror-trapped antiprotons, which would produce seemingly-identical annihilation signals upon hitting the trap wall. In this paper, we discuss possible sources of mirror-trapped antiprotons and show that antihydrogen and antiprotons can be readily distinguished, often with the aid of applied electric fields, by analyzing the annihilation locations and times. We further discuss the general properties of antiproton and antihydrogen trajectories in this magnetic geometry, and reconstruct the antihydrogen energy distribution from the measured annihilation time history., Comment: 17 figures

The ALPHA experiment, located at CERN, aims to compare the properties of antihydrogen atoms with those of hydrogen atoms. The neutral antihydrogen atoms are trapped using an octupole magnetic trap. The trap region is surrounded by a three layered silicon detector used to reconstruct the antiproton annihilation vertices. This paper describes a method we have devised that can be used for reconstructing annihilation vertices with a good resolution and is more efficient than the standard method currently used for the same purpose.

The goal of the ALPHA experiment is the production, trapping and spectroscopy of antihydrogen. A direct comparison of the ground state hyperfine spectra in hydrogen and antihydrogen has the potential to be a high-precision test of CPT symmetry. We present a novel method for measuring the strength of a microwave field for hyperfine spectroscopy in a Penning trap. This method incorporates a non-destructive plasma diagnostic system based on electrostatic modes within an electron plasma. We also show how this technique can be used to measure the cyclotron resonance of the electron plasma, which can potentially serve as a non-destructive measurement of plasma temperature.

The ALPHA experiment has succeeded in trapping antihydrogen, a major milestone on the road to spectroscopic comparisons of antihydrogen with hydrogen. An annihilation vertex detector, which determines the time and position of antiproton annihilations, has been central to this achievement. This detector, an array of double-sided silicon microstrip detector modules arranged in three concentric cylindrical tiers, is sensitive to the passage of charged particles resulting from antiproton annihilation. This article describes the method used to reconstruct the annihilation location and to distinguish the annihilation signal from the cosmic ray background. Recent experimental results using this detector are outlined.

ALPHA is one of the experiments situated at CERN's Antiproton Decelerator (AD). A Silicon Vertex Detector (SVD) is placed to surround the ALPHA atom trap. The main purpose of the SVD is to detect and locate antiproton annihilation events by means of the emitted charged pions. The SVD system is presented with special focus given to the design, fabrication and performance of the modules.

ALPHA is an experiment at CERN, whose ultimate goal is to perform a precise test of CPT symmetry with trapped antihydrogen atoms. After reviewing the motivations, we discuss our recent progress toward the initial goal of stable trapping of antihydrogen, with some emphasis on particle detection techniques., Comment: Invited talk presented at the Fifth Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, June 28-July 2, 2010

Search and rescue robots can benefit from small size as it facilitates access to voids and movement in cramped quarters. Yet, small robots cannot be the entire answer for urban search and rescue because small size limits the size of actuators, sensor payloads, computational capacity and battery capacity. Nonetheless, we are attempting to alleviate these limitations by developing the hardware and software infrastructure for heterogeneous, wireless sensor/actuator/control networks that is well-suited to miniature search and rescue robots, as well as a host of other relevant applications. These networks of application-specific sensors, actuators and intelligence will be assembled from a backbone that includes scalable computing, a flexible I/O bus, and multi-hop data networking. But two things will ultimately give our wireless infrastructure its novelty: a dual-baseband communications layer and the embedded virtual machine. The dual-baseband communications layer augments the standard data communication layer with a secondary, sub-millisecond synchronization layer to permit high-fidelity, deterministic, distributed control across the network. The determinism of this dual-baseband communications layer, in turn, enables the creation of the embedded virtual machine, which is a programming construct that abstracts away the physical sensor/actuator/control nodes. With this infrastructure, programming will not be done at the node level, as in conventional wireless sensor networks. Instead, programming will be done at the task level with port-based objects distributed across physical resources as necessary at either compile-time or run-time. At compile-time, the system can assist in the specification of the physical network, while at run-time the system can react to changes in configuration, such as nodes exhausting their batteries or losing connectivity. This paper describes progress to-date on developing this scalable infrastructure, specifically the RecoNode high-performance, dynamically-reconfigurable computational node for the Terminator-Bot crawling robot and the FireFly mid-performance node, as well as their real-time software.

We report the application of evaporative cooling to clouds of trapped antiprotons, resulting in plasmas with measured temperature as low as 9~K. We have modeled the evaporation process for charged particles using appropriate rate equations. Good agreement between experiment and theory is observed, permitting prediction of cooling efficiency in future experiments. The technique opens up new possibilities for cooling of trapped ions and is of particular interest in antiproton physics, where a precise \emph{CPT} test on trapped antihydrogen is a long-standing goal., Comment: 5 pages, 4 figures

A comparison of the 1S-2S transitions of hydrogen and antihydrogen will yield a stringent test of CPT conservation. Necessarily, the antihydrogen atoms need to be trapped to perform high precision spectroscopy measurements. Therefore, an approximately 0.75 T deep neutral atom trap, equivalent to about 0.5 K for ground state (anti)hydrogen atoms, has been superimposed on a Penning-Malmberg trap in which the anti-atoms are formed. The antihydrogen atoms are produced following a number of steps. A bunch of antiprotons from the CERN Antiproton Decelerator is caught in a Penning-Malmberg trap and subsequently sympathetically cooled and then compressed using rotating wall electric fields. A positron plasma, formed in a separate accumulator, is transported to the main system and also compressed. Antihydrogen atoms are then formed by mixing the antiprotons and positrons. The velocity of the anti-atoms, and their binding energies, will strongly depend on the initial conditions of the constituent particles, for example their temperatures and densities, and on the details of the mixing process. In this paper the complete lifecycle of antihydrogen atoms will be presented, starting with the production of the constituent antiparticles and the description of the manipulations necessary to prepare them appropriately for antihydrogen formation. The latter will also be described, as will the possible fates of the anti-atoms.

Most small robots require a tethered connection with a power and control source. The tether has advantages, namely robust communication and safe recovery, and disadvantages, tangling with obstacles and rough terrain. Active tether is a new research area for tethered robot systems. It provides continuously distributed form of actuation for robots that results from the effect of water hammer. It also reduces the friction of the tether by the jerks from the water hammer effect. In this paper, we duplicate the active tethered system and test the performance of the active tethered system by comparing it with passive tethered system under our test conditions for mobile robot. The two experimental comparison tests are distance test and drag test, which all show the advantage of the active tethered system. Furthermore, we address the broad impact of this novel form of locomotion.

The smallest semiconductor spintronic devices possible for logic or memory will likely involve individual control of single spins while leaving nearby spins unaffected[1]. Readout of the stored state, or the result of a logic operation, would then be done by single-spin readout. Use of electric fields to control individual spins through the spin-orbit interaction is an attractive, scalable alternative to attempting to confine oscillating magnetic fields. Previous work on spins in quantum dots in a static magnetic field has shown that a single vertical electrical gate can be used to fully control the spin orientation[2]. For electron spins in InAs/GaAs quantum dots the spin reorientation times are predicted to be 6 ns for a 1 Tesla static magnetic field, and 0.6 ns for a 10 Tesla static magnetic field. The same geometry, when applied to a the single electron spin bound to a silicon donor in GaAs, yields spin reorientation times of 30 ns for a 4 Tesla magnetic field. More rapid spin manipulation in much smaller magnetic fields would be highly desirable. The substitutional Mn acceptor in GaAs has a large orbital moment, and thus is especially attractive for electrically-driven spin reorientation through the spin-orbit interaction. A geometry with two perpendicular electric fields has been predicted to yield potential spin manipulation frequencies in excess of 10 GHz[3] for electric fields in excess of 20 kV/cm, however the two perpendicular fields required complicates the device geometry.

Cold antihydrogen has been produced at CERN (Amoretti et al. (Nature, 419, 456 (2002)), Gabrielse et al. (Phys. Rev. Lett. 89, 213401 (2002))), with the aim of performing a high-precision spectroscopic comparison with hydrogen as a test of the CPT symmetry. Hydrogen, a unique system used for the development of quantum mechanics and quantum electrodynamics, has been continuously used to produce high-precision tests of theories and measurements of fundamental constants and can lead to a very sensitive search for CPT violation. After the initial production of cold antihydrogen atoms by the ATHENA group, the ALPHA Collaboration ( http://alpha.web.cern.ch/ ) has set forth on an experiment to trap and perform high-resolution laser spectroscopy on the 1S-2S transition of both atoms. In this contribution, we will review the motivations, goals, techniques, and recent developments towards this fundamental physics test. We present new discussion on predicted lineshapes for the 1S-2S spectroscopy of trapped atoms in a regime not discussed before.

A microchannel plate (MCP)/phosphor screen assembly has been used to destructively measure the radial profile of cold, confined antiprotons, electrons, and positrons in the ALPHA experiment, with the goal of using these trapped particles for antihydrogen creation and confinement. The response of the MCP to low energy (10-200 eV