Non-Hermitian oscillator-like Hamiltonians and λ\lambda-coherent states revisited

Previous $\lambda$-deformed {\it non-Hermitian} Hamiltonians with respect to the usual scalar product of Hilbert spaces dealing with harmonic oscillator-like developments are (re)considered with respect to a new scalar product in order to take into account their property of self-adjointness. The corresponding deformed $\lambda$-states lead to new families of coherent states according to the DOCS, AOCS and MUCS points of view.Comment: 10 page

Exploring the electron density in plasmas induced by extreme ultraviolet radiation in argon

The new generation of lithography tools use high energy EUV radiation which ionizes the present background gas due to photoionization. To predict and understand the long term impact on the highly delicate mirrors It is essential to characterize these kinds of EUV-induced plasmas. We measured the electron density evolution in argon gas during and just after irradiation by a short pulse of EUV light at 13.5 nm by applying microwave cavity resonance spectroscopy. Dependencies on EUV pulse energy and gas pressure have been explored over a range relevant for industrial applications. Our experimental results show that the maximum reached electron density depends linearly on pulse energy. A quadratic dependence - caused by photoionization and subsequent electron impact ionization by free electrons - is found from experiments where the gas pressure is varied. This is demonstrated by our theoretical estimates presented in this manuscript as well.Comment: submitted to J. Phys. D. 16 pages, 8 figure

Motion plan changes predictably in dyadic reaching

Parents can effortlessly assist their child to walk, but the mechanism behind such physical coordination is still unknown. Studies have suggested that physical coordination is achieved by interacting humans who update their movement or motion plan in response to the partner's behaviour. Here, we tested rigidly coupled pairs in a joint reaching task to observe such changes in the partners' motion plans. However, the joint reaching movements were surprisingly consistent across different trials. A computational model that we developed demonstrated that the two partners had a distinct motion plan, which did not change with time. These results suggest that rigidly coupled pairs accomplish joint reaching movements by relying on a pre-programmed motion plan that is independent of the partner's behaviour

Males and females evolve riskier traits in populations with eavesdropping parasitoids

Predation and/or parasitism often limits the evolution of conspicuous male traits and female preferences because conspicuous traits can attract predators or parasites and it is costly for females to associate with males that attract predators or parasites. As a result, males and females in high-risk populations are expected to evolve safer mating behaviors compared to individuals from low-risk populations. We tested this antagonistic selection hypothesis in the field cricket Gryllus lineaticeps. Males produce chirped songs, and both female crickets and the eavesdropping parasitoid fly Ormia ochracea prefer faster chirp rates. The flies attack the field crickets late in the breeding season and parasitized crickets die. We used a common garden rearing design to test for evolved differences in songs and preferences between high- and low-risk populations. In contrast to predictions of the antagonistic selection hypothesis, males from high-risk populations produced faster (riskier) chirp rates and females preferred faster chirps. We suggest that late-season parasitism selects for increased investment in reproductive traits to maximize reproduction before the advent of parasitoid activity (“late-season parasitism hypothesis”), which would at least explain riskier female preferences and potentially riskier male songs in the high-risk populations. Predation and parasitism may thus have diverse and unexpected effects on the evolution of reproductive behavior, depending upon the temporal pattern of predator- or parasite-induced mortality. Significance statement Mating signals are typically conspicuous and not only attract partners but also predators and parasites. Even the silent mating partner may experience predation or parasitism by associating with the signaler. Under these circumstances, it is commonly assumed that natural and sexual selection act in opposite directions, effectively limiting the evolution of conspicuous signals and preferences. We demonstrate that an eavesdropping parasitic fly caused the evolution of preferences, and potentially songs, in a field cricket in the opposite, more conspicuous, direction than predicted by antagonistic selection. We argue that the temporal pattern of parasitism in relation to the reproductive season likely causes this unexpected evolutionary pattern. We propose the late-season parasitism hypothesis as an alternative to the antagonistic selection hypothesis, which might better explain more conspicuous mating trait values in other species that experience seasonal predation or parasitism

Males and females evolve riskier traits in populations with eavesdropping parasitoids

Predation and/or parasitism often limits the evolution of conspicuous male traits and female preferences because conspicuous traits can attract predators or parasites and it is costly for females to associate with males that attract predators or parasites. As a result, males and females in high-risk populations are expected to evolve safer mating behaviors compared to individuals from low-risk populations. We tested this antagonistic selection hypothesis in the field cricket Gryllus lineaticeps. Males produce chirped songs, and both female crickets and the eavesdropping parasitoid fly Ormia ochracea prefer faster chirp rates. The flies attack the field crickets late in the breeding season and parasitized crickets die. We used a common garden rearing design to test for evolved differences in songs and preferences between high- and low-risk populations. In contrast to predictions of the antagonistic selection hypothesis, males from high-risk populations produced faster (riskier) chirp rates and females preferred faster chirps. We suggest that late-season parasitism selects for increased investment in reproductive traits to maximize reproduction before the advent of parasitoid activity (“late-season parasitism hypothesis”), which would at least explain riskier female preferences and potentially riskier male songs in the high-risk populations. Predation and parasitism may thus have diverse and unexpected effects on the evolution of reproductive behavior, depending upon the temporal pattern of predator- or parasite-induced mortality. Significance statement Mating signals are typically conspicuous and not only attract partners but also predators and parasites. Even the silent mating partner may experience predation or parasitism by associating with the signaler. Under these circumstances, it is commonly assumed that natural and sexual selection act in opposite directions, effectively limiting the evolution of conspicuous signals and preferences. We demonstrate that an eavesdropping parasitic fly caused the evolution of preferences, and potentially songs, in a field cricket in the opposite, more conspicuous, direction than predicted by antagonistic selection. We argue that the temporal pattern of parasitism in relation to the reproductive season likely causes this unexpected evolutionary pattern. We propose the late-season parasitism hypothesis as an alternative to the antagonistic selection hypothesis, which might better explain more conspicuous mating trait values in other species that experience seasonal predation or parasitism

Myynninedistäminen mainonna avulla

Opinnäytetyössä etsittiin tehokkaita myynninedistämisen keinoja Select Service Partner Finlandin lentokentällä sijaitsevaan elintarvikekioski Pointtiin. Tutkimusongelmana oli selvittää, millainen mainos tehoaa asiakkaisiin kyseisessä toimintaympäristössä sekä millaisia tuotteita kannattaisi mainostaa tai laittaa tarjoukseen. Myynninedistämisprojektin aloitushetkellä syksyllä 2009 Point oli ollut nykyisessä muodossaan noin vuoden, eivätkä kaikki potentiaaliset asiakkaat olleet vielä löytäneet sitä. Pointtia oli tarkoitus tehdä nykyistä tunnetummaksi kentän henkilökunnan ja matkustajien keskuudessa. Myynnin kasvun edellytettiin tapahtuvan niin, että raaka-aine ja henkilöstökulut pysyivät ennallaan. Projektin teoreettinen viitekehys rakentuu asiakassuuntaisesta markkinoinnista, myynninedistämisestä ja mainonnan käytössä olevista muodoista sekä kilpailukeinoista. Vaikka opinnäytetyö käsittelee konkreettisesti myynnin kasvattamista nimenomaan mainonnan avulla, työssä tarkastellaan myös asiakaspalvelun teoriaa työntekijän mahdollisuutena edistää tarjoustuotteiden myyntiä. Point kioskille suunniteltiin erilaisia mainoksia ja pakettitarjouskampanjoita sekä muunlaista myynninedistämismateriaalia kuten grilli- ja pullapassit. Mainokset sekä materiaalit suunniteltiin ja laitettiin esille ajanjaksolla syksystä 2009 syksyyn 2010. Mainostettujen tuotteiden myyntilukuja verrattiin kassajärjestelmästä saatavien raportointitaulukoiden avulla. Vertailukohteena olivat mainoksia edeltäneet ja niiden jälkeen toteutuneet myyntiluvut. Tulosten tulkintamenetelmänä käytettiin dokumenttianalyysiä, jossa kvantitatiivinen aineisto analysoitiin kvalitatiivisesti. Lopuksi tuloksia analysoimalla pääteltiin, minkälainen mainonta olisi kannattavaa jatkossa kyseisessä toimipisteessä. Lisäksi Pointin esimiehelle tehtiin asiantuntijahaastattelu tukemaan saatuja tuloksia. Tuloksista selviää, että pitkäaikaiset pakettitarjoukset eivät juuri tehonneet asiakkaisiin. Palautteita ja myyntilukuja seuraamalla kannattavampaa olisi tulevaisuudessa mainostaa lyhytaikaisia selkeästi tarjoushintaisia tuotteita tai määräalennuksia. Mainoksien laittaminen näkyville myös myymälässä olevan television kautta voisi olla kokeilemisen arvoista jatkossa. Passit ja kioskin seinillä olevat tuotteita esittelevät mainokset todettiin toimiviksi kyseisessä toimipisteessä. Matkustavien asiakkaiden houkutteluun tehokas keino voisi olla mainoslehtisten jako ylemmän kerroksen kahvilaan. Pointin myynti on saatu kasvamaan projektiin käytetyn vuoden aikana 10,44 prosenttia. Tuloksen perusteella voidaan päätellä, että tavoitteeseen on päästy ja saatu myynti kääntymään kasvuun.This thesis investigates successful sales promotion methods for Select Service Partner Finland’s Kiosk, Point, which is located at the airport. The purpose of the study was to find out what type of advertisement is effective for customers in this environment and which products are worth to be placed on sales and in advertisements. When the project began Kiosk Point had been in its format for a year and all the potential customers had not found it. The objective of the project was to gain visibility among airport staff and passengers. Sales needed to be increased without having an effect on the material and staff costs. The theoretical section of the thesis outlines customer marketing, sales promoting as well as the means of advertisement and competition. Although this thesis concretely processes the increase of sales as a result of advertisement it also examines customer service in theory and employee’s’ possibility to increase the marketing of products that are on sale. Different forms of advertisements and sales campaigns were drawn up for the Point Kiosk and also sales promotion materials like grill and bun passes were created. Advertisements and materials were planned and introduced from fall 2009 to fall 2010. The sales figures of the advertised products were compared with cash desk reports. The compared objects were the sales figures before and after advertisement. The study is based on a document analysis where quantitative material is qualitatively analyzed. The format of advertisement for this appropriate kiosk was derived from the results. Point’s superior was interviewed to support the results of the study. The results show that long term sales were not affected by customer buying behavior. Based on the feedback and sales figures, it would be worthwhile to advertise products for a short period or use different sales campaigns. Advertising on the kiosk’s television should be considered in the future. Passes and advertisements on walls of the kiosk were functional. Placing advertisements at the upstairs coffee shop might bring more customers to Point. Point’s sale has increased by 10.44 percent during the project. As can be seen from the results the thesis reached its objective and the sales are increasing

El corte de los modelos de volumen utilizados para el cálculo por elementos finitos

En este trabajo se presenta un método para calcular y representar el corte de modelos tridimensionales. Para representar resultados se debe previamente determinar una superficie. En el caso de la representación de valores en cortes del modelo, esta superficie es la intersección con el plano de corte. En este trabajo se describe un método rápido y simple para el cálculo de la sección así como el método empleado para la interpolación de los valores a representar.In this work, a method to compute section of 3D finite element models is presented. A surface of model must be evaluate to represent any results. In the section representation, this surface is the intersection with the section plane. A simple and fast method to determine section model and to interpolate results is here developed.Peer Reviewe

Laser Guide Stars for Extremely Large Telescopes: Efficient Shack-Hartmann Wavefront Sensor Design using Weighted center-of-gravity algorithm

Over the last few years increasing consideration has been given to the study of Laser Guide Stars (LGS) for the measurement of the disturbance introduced by the atmosphere in optical and near-infrared astronomical observations from the ground. A possible method for the generation of a LGS is the excitation of the Sodium layer in the upper atmosphere at approximately 90 km of altitude. Since the Sodium layer is approximately 10 km thick, the artificial reference source looks elongated, especially when observed from the edge of a large aperture. The spot elongation strongly limits the performance of the most common wavefront sensors. The centroiding accuracy in a Shack-Hartmann wavefront sensor, for instance, decreases proportionally to the elongation (in a photon noise dominated regime). To compensate for this effect a straightforward solution is to increase the laser power, i.e. to increase the number of detected photons per subaperture. The scope of the work presented in this paper is twofold: an analysis of the performance of the Weighted Center of Gravity algorithm for centroiding with elongated spots and the determination of the required number of photons to achieve a certain average wavefront error over the telescope aperture.Comment: 10 pages, 14 figure

A Statistical Analysis of the SOT-Hinode Observations of Solar Spicules and their Wave-like Behavior

We consider a first important parameter of spicules as observed above the solar visible limb: their apparent diameter as a function of the height above the limb which determines their aspect ratio and leads to the discussion of their magnetic origin using the flux tube approximation. We found that indeed spicules show a whole range of diameters, including unresolved "interacting spicules" (I-S), depending of the definition chosen to characterize this ubiquitous dynamical phenomenon occurring into a low coronal surrounding. 1-D Fourier amplitude spectra (AS) made at different heights above the limb are shown for the first time. A definite signature in the 0.18 to 0.25 Mm range exists, corresponding to the occurrence of the newly discovered type II spicules and, even more impressively, large Fourier amplitudes are observed in the 0.3 to the 1.2 Mm range of diameters and spacing, in rough agreement with what historical works were reporting. Additionally, some statistically significant behavior, based on AS computed for different heights above the limb, is discussed. "Time slice or x-t diagrams" revealing the dynamical behavior of spicules are also analyzed. They show that most of spicules have multiple structures (similarly to the doublet spicules) and they show impressive transverse periodic fluctuations which were interpreted as upward kink or Alfven waves. Evidence of the helical motion in spicules is now well evidenced, the typical periods of the apparent oscillation being around 120 sec. A fine analysis of the time-slice diagram as a function of the effective heights shows an interesting new feature near the 2 Mm height. We speculate on the interpretation of this feature as being a result of the dynamical specificities of the spicule helical motion as seen in these unprecedented high resolution HCaII line emission time series.Comment: 21 pages, 8 figurs, 1 tabl

Tradeoffs limit the evolution of male traits that are attractive to females

Tradeoffs occur between a variety of traits in a diversity of organisms, and these tradeoffs can have major effects on ecological and evolutionary processes. Far less is known, however, about tradeoffs between male traits that affect mate attraction than about tradeoffs between other types of traits. Previous results indicate that females of the variable field cricket, Gryllus lineaticeps, prefer male songs with higher chirp rates and longer chirp durations. In the current study, we tested the hypothesis that a tradeoff between these traits affects the evolution of male song. The two traits were negatively correlated among full-sibling families, consistent with a genetically based tradeoff, and the tradeoff was stronger when nutrients were limiting. In addition, for males from 12 populations reared in a common environment, the traits were negatively correlated within populations, the strength of the tradeoff was largely invariant across populations, and the within-population tradeoff predicted how the traits have evolved among populations. A widespread tradeoff thus affects male trait evolution. Finally, for males from four populations assayed in the field, the traits were negatively correlated within and among populations. The tradeoff is thus robust to the presence of environmental factors that might mask its effects. Together, our results indicate there is a fundamental tradeoff between male traits that: (i) limits the ability of males to produce multiple attractive traits; (ii) limits how male traits evolve; and (iii) might favor plasticity in female mating preferences. Includes Supplementary Materials