Robust Online Hamiltonian Learning

In this work we combine two distinct machine learning methodologies, sequential Monte Carlo and Bayesian experimental design, and apply them to the problem of inferring the dynamical parameters of a quantum system. We design the algorithm with practicality in mind by including parameters that control trade-offs between the requirements on computational and experimental resources. The algorithm can be implemented online (during experimental data collection), avoiding the need for storage and post-processing. Most importantly, our algorithm is capable of learning Hamiltonian parameters even when the parameters change from experiment-to-experiment, and also when additional noise processes are present and unknown. The algorithm also numerically estimates the Cramer-Rao lower bound, certifying its own performance.Comment: 24 pages, 12 figures; to appear in New Journal of Physic

Quasi-probability representations of quantum theory with applications to quantum information science

This article comprises a review of both the quasi-probability representations of infinite-dimensional quantum theory (including the Wigner function) and the more recently defined quasi-probability representations of finite-dimensional quantum theory. We focus on both the characteristics and applications of these representations with an emphasis toward quantum information theory. We discuss the recently proposed unification of the set of possible quasi-probability representations via frame theory and then discuss the practical relevance of negativity in such representations as a criteria for quantumness.Comment: v3: typos fixed, references adde

Association between overweight, obesity and self-perceived job insecurity in German employees

<p>Abstract</p> <p>Background</p> <p>Recent studies have shown an association between job insecurity and morbidity as well as mortality, however until now, knowledge about a potential association between job insecurity and overweight or obesity has been lacking.</p> <p>Methods</p> <p>In order to identify a possible association between job insecurity and overweight or obesity, we analysed data from the German Socioeconomic Panel (GSOEP) 2004/2005, a longitudinal study of private households in Germany. In this representative cohort of the German adult population, living and working conditions were observed. Data on Body Mass Index (BMI) and self-perceived probability of job loss within the next 2 years were available for 10,747 adults either employed or attending training programs.</p> <p>Results</p> <p>We identified 5,216 (49%) individuals as being overweight (BMI > 25 kg/m²) and 1,358(13%) individuals as being obese (BMI > 30 kg/m²). A total of 5,941 (55%) participants reported having concerns regarding job insecurity. In the multivariate analysis - after adjustment for relevant confounders - a statistically significant association between obesity and job insecurity (100% probability for losing the job in the following two years) could be observed with an adjusted odds ratio of 2.55 (95% confidence interval: 1.09-5.96).</p> <p>Conclusions</p> <p>Because of these results, we were able to conclude that overweight and obese persons perceive job insecurity more often than their normal weight counterparts in Germany and that the concurrence of obesity and job insecurity might lead employees into a vicious cycle. Further research with an emphasis on the occupational setting might be necessary in order to establish useful preventive programmes at the workplace.</p

Multifaceted roles of transcription factors during plant embryogenesis

Transcription factors (TFs) are diverse groups of regulatory proteins. Through their specific binding domains, TFs bind to their target genes and regulate their expression, therefore TFs play important roles in various growth and developmental processes. Plant embryogenesis is a highly regulated and intricate process during which embryos arise from various sources and undergo development; it can be further divided into zygotic embryogenesis (ZE) and somatic embryogenesis (SE). TFs play a crucial role in the process of plant embryogenesis with a number of them acting as master regulators in both ZE and SE. In this review, we focus on the master TFs involved in embryogenesis such as BABY BOOM (BBM) from the APETALA2/Ethylene-Responsive Factor (AP2/ERF) family, WUSCHEL and WUSCHEL-related homeobox (WOX) from the homeobox family, LEAFY COTYLEDON 2 (LEC2) from the B3 family, AGAMOUS-Like 15 (AGL15) from the MADS family and LEAFY COTYLEDON 1 (LEC1) from the Nuclear Factor Y (NF-Y) family. We aim to present the recent progress pertaining to the diverse roles these master TFs play in both ZE and SE in Arabidopsis, as well as other plant species including crops. We also discuss future perspectives in this context

Wigner formalism for a particle on an infinite lattice: dynamics and spin

The recently proposed Wigner function for a particle in an infinite lattice (Hinarejos M, Banuls MC and Perez A 2012 New J. Phys. 14 103009) is extended here to include an internal degree of freedom as spin. This extension is made by introducing a Wigner matrix. The formalism is developed to account for dynamical processes, with or without decoherence. We show explicit solutions for the case of Hamiltonian evolution under a position-dependent potential, and for evolution governed by a master equation under some simple models of decoherence, for which the Wigner matrix formalism is well suited. Discrete processes are also discussed. Finally, we discuss the possibility of introducing a negativity concept for the Wigner function in the case where the spin degree of freedom is included

Isolation of an embryogenic line from non-embryogenic Brassica napus cv. Westar through microspore embryogenesis

Brassica napus cultivar Westar is non-embryogenic under all standard protocols for induction of microspore embryogenesis; however, the rare embryos produced in Westar microspore cultures, induced with added brassinosteroids, were found to develop into heritably stable embryogenic lines after chromosome doubling. One of the Westar-derived doubled haploid (DH) lines, DH-2, produced up to 30% the number of embryos as the highly embryogenic B. napus line, Topas DH4079. Expression analysis of marker genes for embryogenesis in Westar and the derived DH-2 line, using real-time reverse transcription-PCR, revealed that the timely expression of embryogenesis-related genes such as LEAFY COTYLEDON1 (LEC1), LEC2, ABSCISIC ACID INSENSITIVE3, and BABY BOOM1, and an accompanying down-regulation of pollen-related transcripts, were associated with commitment to embryo development in Brassica microspores. Microarray comparisons of 7 d cultures of Westar and Westar DH-2, using a B. napus seed-focused cDNA array (10 642 unigenes), identified highly expressed genes related to protein synthesis, translation, and response to stimulus (Gene Ontology) in the embryogenic DH-2 microspore-derived cell cultures. In contrast, transcripts for pollen-expressed genes were predominant in the recalcitrant Westar microspores. Besides being embryogenic, DH-2 plants showed alterations in morphology and architecture as compared with Westar, for example epinastic leaves, non-abscised petals, pale flower colour, and longer lateral branches. Auxin, cytokinin, and abscisic acid (ABA) profiles in young leaves, mature leaves, and inflorescences of Westar and DH-2 revealed no significant differences that could account for the alterations in embryogenic potential or phenotype. Various mechanisms accounting for the increased capacity for embryogenesis in Westar-derived DH lines are considered

Quantum Fourier transform, Heisenberg groups and quasiprobability distributions

This paper aims to explore the inherent connection among Heisenberg groups, quantum Fourier transform and (quasiprobability) distribution functions. Distribution functions for continuous and finite quantum systems are examined first as a semiclassical approach to quantum probability distribution. This leads to studying certain functionals of a pair of "conjugate" observables, connected via the quantum Fourier transform. The Heisenberg groups emerge naturally from this study and we take a rapid look at their representations. The quantum Fourier transform appears as the intertwining operator of two equivalent representation arising out of an automorphism of the group. Distribution functions correspond to certain distinguished sets in the group algebra. The marginal properties of a particular class of distribution functions (Wigner distributions) arise from a class of automorphisms of the group algebra of the Heisenberg group. We then study the reconstruction of Wigner function from the marginal distributions via inverse Radon transform giving explicit formulas. We consider applications of our approach to quantum information processing and quantum process tomography.Comment: 39 page

Framed Hilbert space: hanging the quasi-probability pictures of quantum theory

Building on earlier work, we further develop a formalism based on the mathematical theory of frames that defines a set of possible phase-space or quasi-probability representations of finite-dimensional quantum systems. We prove that an alternate approach to defining a set of quasi-probability representations, based on a more natural generalization of a classical representation, is equivalent to our earlier approach based on frames, and therefore is also subject to our no-go theorem for a non-negative representation. Furthermore, we clarify the relationship between the contextuality of quantum theory and the necessity of negativity in quasi-probability representations and discuss their relevance as criteria for non-classicality. We also provide a comprehensive overview of known quasi-probability representations and their expression within the frame formalism.Comment: 46 pages, 1 table, contains a review of finite dimensional quasi-probability function

The impact of employee level and work stress on mental health and GP service use: an analysis of a sample of Australian government employees

BACKGROUND: This study sought to identify the extent to which employee level and work stressors were associated with mental health problems experienced by Australian government employees, and with their use of primary care services. METHODS: 806 government employees aged between 40 and 44 years were surveyed as part of an epidemiological study conducted in Australia. Data collected from participants included sociodemographic attributes, physical health, psychological measures and work stressors relating to job control, job demands, job security and skills discretion at work. For 88% of these participants, information on visits made to general practitioners (GPs) for the six months before and after their survey interview was obtained from health insurance records. RESULTS: When work stress and personal factors were taken into account, men at more junior levels reported better mental health, more positive affect and used fewer GP services. Women at middle-management levels obtained less GP care than their more senior counterparts. Both men and women who reported higher levels of work stress were found to have poorer mental health and well-being. The impact of such stressors on GP service use, however, differed for men and women. CONCLUSION: Measures of work stress and not employee level affect the mental health and well-being of government employees. For governments with responsibility for funding health care services, reducing work stress experienced by their own employees offers potential benefits by improving the health of their workforce and reducing outlays for such services

Induction of androgenesis and production of haploid embryos in anther cultures of borage (Borago officinalis L.)

[EN] Borage (Borago officinalis L.) is an important medicinal plant with different culinary, pharmaceutical and industrial properties. Unfortunately, there are no published reports on the establishment of protocols to produce DHs in this species up to now. In this work, we show for the first time the induction of borage microspores to become embryogenic calli, from which haploid embryos are produced. In addition, we evaluated the effect of using different flower bud sizes, carbon sources, concentrations of 2,4-D and BAP, cold (4 A degrees C) pretreatments and heat shock treatments. Production of total calli, embryogenic calli and callus-derived embryos was differently affected by the different parameters studied. Our results showed that the use of 5-7 mm-long flower buds, a cold (4 A degrees C) pretreatment during 4 days, a 32 A degrees C heat shock for 3 days, and the addition of 3 % maltose and 2 mgl(-1) 2,4-D and 1 mgl(-1) BAP to the culture medium, was beneficial for embryo production. Overall, this work demonstrates that DH technology is possible in borage, and opens the door for future improvements needed to finally obtain borage DH plants.Eshaghi, ZC.; Abdollahi, MR.; Moosavi, SS.; Deljou, A.; Seguí-Simarro, JM. (2015). Induction of androgenesis and production of haploid embryos in anther cultures of borage (Borago officinalis L.). Plant Cell, Tissue and Organ Culture. 122:321-329. doi:10.1007/s11240-015-0768-5S321329122Abdollahi MR, Moieni A, Javaran MJ (2004) Interactive effects of shock and culture density on embryo induction in isolated microspore culture of Brassica napus L. cv. Global Iranian J Biotech 2:97–100Bohanec B, Neskovic M, Vujicic R (1993) Anther culture and androgenetic plant regeneration in buckwheat (Fagopyrum esculentum Moench). Plant Cell Tissue Organ Cult 35:259–266Calleberg E, Johansson L (1996) Effect of gelling agents on anther cultures. In: Jain SM, Sopory SK, Veilleux RE (eds) In vitro haploid production in higher plants, vol 23. Springer, Netherlands, pp 189–203Custers JBM, Cordewener JHG, Nöllen Y, Dons JJ, van Lookeren-Campagne MM (1994) Temperature controls both gametophytic and sporophytic development in microspore cultures of Brassica napus. Plant Cell Rep 13:267–271Ferrie AMR (2013) Advances in microspore culture technology: a biotechnological tool for the improvement of medicinal plants. In: Chandra S et al (eds) Biotechnology for medicinal plants. Springer, Berlin, pp 191–206Ferrie AMR, Caswell KL (2011) Isolated microspore culture techniques and recent progress for haploid and doubled haploid plant production. Plant Cell Tissue Organ Cult 104:301–309Ferrie AMR, Bethune T, Mykytyshyn M (2011) Microspore embryogenesis in the Apiaceae. Plant Cell Tissue Organ Cult 104:399–406Forster BP, Heberle-Bors E, Kasha KJ, Touraev A (2007) The resurgence of haploids in higher plants. Trends Plant Sci 12:368–375Gamborg OL, Miller RA, Ojiwa K (1968) Nutrient requirements of suspension culture of soybean root callus. Exp Cell Res 50:151–158Guil-Guerrero JL, García-Maroto F, Vilches-Ferrón MA, López-Alonso D (2003) Gamma-linolenic acid from fourteen Boraginaceae species. Ind Crop Prod 18:85–89Horrobin DF (1983) The regulation of prostaglandin biosynthesis by the manipulation of essential fatty acid metabolism. Rev Pure Appl Pharmacol Sci 4:339–383Irikova T, Grozeva S, Rodeva V (2011) Anther culture in pepper (Capsicum annuum L.) in vitro. Acta Physiol Plant 33:1559–1570Lauxen MS, Kaltchuk-Santos E, Hu CY, Callegari-Jacques SM, Bodanese-Zanettini MH (2003) Association between floral bud size and developmental stage in soybean microspores. Braz Arch Biol Technol 46:515–520Leach CR, Mayo O, Bürger R (1990) Quantitatively determined self-incompatibility. Outcrossing in Borago officinalis. Theoret Appl Genetics 79:427–430Lichter R (1982) Induction of haploid plants from isolated pollen of Brassica napus. Z Pflanzenphysiol 105:427–434Maluszynski M, Kasha KJ, Szarejko I (2003) Published doubled haploid protocols in plant species. In: Maluszynski M, Kasha KJ, Forster BP, Szarejko I (eds) Doubled haploid production in crop plants. A manual. Kluwer, Dordrecht, pp 309–335Maraschin SF, de Priester W, Spaink HP, Wang M (2005) Androgenic switch: an example of plant embryogenesis from the male gametophyte perspective. J Exp Bot 56:1711–1726McDonald BE, Fitzpatrick K (1998) Designer Vegetable Oils. In: Mazza G (ed) Functional foods, biochemical and processing aspects. Technomic Publ Co. Inc, Lancaster, pp 265–291Ozkum D, Tipirdamaz R (2002) The effects of cold treatment and charcoal on the in vitro androgenesis of pepper (Capsicum annuum L.). Turk J Bot 26:131–139Parra-Vega V, González-García B, Seguí-Simarro JM (2013a) Morphological markers to correlate bud and anther development with microsporogenesis and microgametogenesis in pepper (Capsicum annuum L.). Acta Physiol Plant 35:627–633Parra-Vega V, Renau-Morata B, Sifres A, Seguí-Simarro JM (2013b) Stress treatments and in vitro culture conditions influence microspore embryogenesis and growth of callus from anther walls of sweet pepper (Capsicum annuum L.). Plant Cell Tissue Organ Cult 112:353–360Raquin C (1983) Utilization of different sugars as carbon sources for in vitro cultures of Petuina. Z Pflanzenphysol 111:453–457Salas P, Rivas-Sendra A, Prohens J, Seguí-Simarro JM (2012) Influence of the stage for anther excision and heterostyly in embryogenesis induction from eggplant anther cultures. Euphytica 184:235–250Seguí-Simarro JM (2010) Androgenesis revisited. Bot Rev 76:377–404Seguí-Simarro JM, Nuez F (2006) Androgenesis induction from tomato anther cultures: callus characterization. Acta Hort 725:855–861Seguí-Simarro JM, Corral-Martínez P, Parra-Vega V, González-García B (2011) Androgenesis in recalcitrant solanaceous crops. Plant Cell Rep 30:765–778Shariatpanahi ME, Bal U, Heberle-Bors E, Touraev A (2006) Stresses applied for the reprogramming of plant microspores towards in vitro embryogenesis. Physiol Plant 127:519–534Simon JE, Chadwick AF, Craker LE (1984) Herbs: an indexed bibliography. 1971–1980. The scientific literature on selected herbs, and aromatic and medicinal plants of the temperate zone. Archon Books, Hamden, CTSkrzypek E, Czyczyło-Mysza I, Marcińska I, Wędzony M (2008) Prospects of androgenetic induction in Lupinus spp. Plant Cell Tissue Organ Cult 94(2):131–137Snape JW (1989) Doubled haploid breeding: theoretical basis and practical applications. In: Mujeeb-Kazi A, Sitch LA (eds) Review of advances in plant biotechnology, 1985–1988: 2nd international symposium genetic manipulation in crops. Mexico and Manila, CIMMYT and IRRI, pp 19–30Tipirdamaz R, Ellialtioğlu Ş (1998) The effects of cold treatments and activated charcoal on ABA contents of anthers and in vitro androgenesis in eggplant (Solanum melongena L.). In: Tsekos I, Moustakas M (eds) Progress in botanical research, Proceedings of the 1st Balkan botanical congress. Kluwer Academic Publishers, The NetherlandsVagera J, Havranek P (1985) In vitro induction of androgenesis in Capsicum annuum L. and its genetic aspests. Biol Plant 27(1):10–21Zur I, Dubas E, Golemiec E, Szechynska-Hebda M, Golebiowska G, Wedzony M (2009) Stress-related variation in antioxidative enzymes activity and cell metabolism efficiency associated with embryogenesis induction in isolated microspore culture of triticale (×Triticosecale Wittm.). Plant Cell Rep 28:1279–128