Zero-phonon linewidth and phonon satellites in the optical absorption of nanowire-based quantum dots

The optical properties of quantum dots embedded in a catalytically grown semiconductor nanowire are studied theoretically. In comparison to dots in a bulk environment, the excitonic absorption is strongly modified by the one-dimensional character of the nanowire phonon spectrum. In addition to pronounced satellite peaks due to phonon-assisted absorption, we find a finite width of the zero-phonon line already in the lowest-order calculation.Comment: final version, to appear in Physical Review Letters (4 pages with 4 figures included, minor changes with respect to first version

The Prehospital assessment of severe trauma patients' performed by the specialist ambulance nurse in Sweden - a phenomenographic study

Background A common feature of prehospital emergency care is the short and fragmentary patient encounters with increased demands for efficient and rapid treatment. Crucial decisions are often made and the premise is the specialist ambulance nurse’s ability to capture the situation instantaneously. The assessment is therefore a pre-requisite for decisions about appropriate actions. However, the low exposure to severe trauma cases in Sweden leads to vulnerability for the specialist ambulance nurse, which makes the assessment more difficult. Our objective was to describe specialist ambulance nurses’ perceptions of assessing patients exposed to severe trauma. Methods This study had a phenomenographic approach and was performed in 2011 as an interview study. 15 specialist ambulance nurses with a minimum of 2.5 years of experience from praxis were included. The analysis of data was performed using phenomenography according to Marton. Results The perceptions of assessing patients exposed to severe trauma were divided into: To be prepared for emergency situations, Confidence in one’s own leadership and Developing professional knowledge. Conclusions This study reveals that the specialist ambulance nurse, on the scene of accident, finds the task of assessment of severe trauma patients difficult and complicated. In some cases, even exceeding what they feel competent to accomplish. The specialist ambulance nurses feel that no trauma scenarios are alike and that more practical skills, more training, exercise and feedback are needed

Die private Bereitstellung öffentlicher Güter : Vergangenheit und Zukunft des kommunalen Liberalismus

In this thesis, the brand construct and its connections to risk, value and trust are explored in a Business-to-Business context. The different characteristics of B2B and B2C marketing is elaborated upon and coupled with brand management strategies viable in the respective markets. Contemporary academic theory on the explored constructs is discussed, and an attempt at conceptually visualizing their suggested linkages is presented. Based on the theoretical findings, a qualitative study is conducted by means of interviews with brand managers and marketing executives with the aim of establishing how Swedish industrial multinational companies employ brand strategies in their market communication, and to what extent the constructs explored are communicated as a part of their brand message. We find empirical evidence that risk, value and trust indeed are important in the brand communication of industrial companies. However, the relative importance of these constructs is found to be highly dependent on a multitude of both internal and external factors, such as the complexity of the offering, the degree of competition in the marketplace, and the amount of required customer interaction. Trust seems to be the construct most commonly incorporated in the branding activities, and value is not as actively stressed as conjectured. The corporate brand appears to be the most important in new tasks, where previous experiences of interaction with the seller is deemed more important in modified and straight re-buys. Similar to consumer marketing, the main merit of having a strong brand equity is the ability to charge price premiums, along with often making the short list of potential suppliers in the customers’ procurement processes. However, many industrial companies do not actively employ brand strategies and dedicated brand managers are not commonplace. Further, it cannot be decisively concluded that a strong brand focus is important for all industrial companies and in all markets. Again, external market characteristics, together with internal organizational conditions need to be taken into account

Positiva och negativa resultat och mödrars upplevelser av tidig hemgång efter förlossning

Förr i tiden fick mödrarna längre eftervård på sjukhus efter förlossningen, men det har blivit allt vanligare att kvinnor nuförtiden blir utskrivna från sjukhuset tidigare efter normal vaginal förlossning. Det är därför viktigt att undersöka faktorer som påverkar mödrars upplevelser av tidig hemgång. Detta examensarbete är en forskning inom Kvinnoprojektet som är ett sammarbete mellan yrkeshögskolan Arcada och Kvinnokiliken (HUS). Syftet med denna forskning är att få en större förståelse för mödrars upplevelser av tidig hemgång och forskningsfrågorna är: Vilka är de positiva och negativa följderna samt mödrars upplevelser av tidig hemgång efter förlossning? Ramona Mercers teori om antagandet av modersrollen valdes som teoretisk referensram. Vi har valt att använda litteraturstudie som metod för att besvara forskningsfrågorna. Tjugo artiklar användes till innehållsanalysen och materialet analyserades enligt induktiv modell. Resultatet presenteras i två huvudkategorier, positiva och negativa resultat. De positiva resultaten har sex underkategorier och de negativa resultaten presenterades i fem underkategorier. Resultat av amning, känslor och upplevelser framkommer i de båda huvudkategorierna. Resultatet har varit varierande och det fanns både fördelar och nackdelar med tidig hemgång i litteraturen. Negativa upplevelser som kom fram innehöll mödrars rädsla, osäkerhet och ångest i samband med tidig hemgång efter förlossning. Mödrars positiva upplevelser av tidig hemgång efter förlossning bestod av självförtroende, självbestämmanderätt, sammanhang inom familjen och tillfredställelse både med amning och postpartum vård.Not long time ago mothers received care at the hospital longer than today after delivery but it has become increasingly common that women nowadays are discharged from hospi-tal sooner after normal vaginal delivery. It is therefore important to investigate factors that affect mothers’ experiences of early discharge. This thesis is a research within Wom-en's Project that is a cooperation between the university of applied science Arcada and women’s clinic (HUS). The purpose of the study is to gain a greater understanding of mothers' experiences of early discharge and the questions are: What are the positive and negative consequences and mothers' experiences of early discharge after childbirth? Ra-mona Mercer’s theory of the adoption of the mother’s roll was chosen as the theoretical framework. Literature review was selected as the method to answer the research ques-tions. Twenty articles were used for content analysis and the material was analyzed ac-cording to an inductive model. The results are presented in two main categories: positive and negative results. Results of breastfeeding, feelings and experiences emerge in both main categories. The results have been varied and there were both advantages and disad-vantages of early discharge in the literature. Negative experiences that emerged included maternal fear, insecurity and anxiety associated with early discharge after childbirth. Ma-ternal positive experiences of early discharge after childbirth consisted of self-confidence, autonomy, context within the family and satisfaction with both breastfeeding and post-partum care.Ennen äidit saivat pitkäaikaisempaa jälkihoitoa sairaalassa normaalin synnytyksen jälkeen, mutta nykyisin on tavallista, että naiset kirjataan ulos aikaisemmin. On tärkeää tutkia mitkä tekijät vaikuttavat äidin kokemuksiin varhaisessa kotiutumisessa. Tämä opinnäytetyö on tutkimus, joka kuuluu ”Kvinnoprojektet” (Suom. Naisprojekti) nimiseen yhteisprojektiin ammattikorkeakoulun Arcadan ja Helsingin Naistenklinikan (HUS) kanssa. Tutkimuksen tarkoitus on saada parempi käsitys äitien kokemuksista varhaisesta kotiutumisesta synnytyksen jälkeen. Tutkittavina kysymyksinä ovat: Mitkä ovat myönteiset ja kielteiset vaikutukset, sekä äitien omia kokemuksia varhaisesta kotiutumisesta synnytyksen jälkeen? Teoreettiseksi viitekehykseksi valittiin Ramona Mercerin teoria äidin roolin omaksumisesta. Päätimme hyödyntää kirjallisuuskatsastusmenetelmää saadaksemme vastaukset tutkimuksen kysymyksiin. Sisällön sekä aineiston induktiiviseen analyysiin valittiin 20 artikkelia. Tulokset esitettiin kahdessa pääryhmässä; positiivisissa ja negatiivisissa. Positiiviset tulokset jaettiin kuuteen alaluokkaan ja negatiiviset viiteen. Tuloksia imetyksestä, tunteista ja kokemuksista esiintyi molemmissa pääluokissa. Tutkimuksen tulokset ovat vaihdelleet, mutta varhaisesta kotiutumisesta löytyi sekä etuja että haittoja. Negatiivisissa kokemuksissa nousi äidin pelko, turvattomuuden tunne ja ahdistuksen tunne liittyen varhaiseen kotiutumiseen synnytyksen jälkeen. Itseluottamus, itsemääräämisoikeus, perheen yhteenkuuluvuus sekä tyytyväisyys imetykseen ja jälkihoitoon muodostivat äitien positiiviset kokemukset

Probing confined phonon modes by transport through a nanowire double quantum dot

Strong radial confinement in semiconductor nanowires leads to modified electronic and phononic energy spectra. We analyze the current response to the interplay between quantum confinement effects of the electron and phonon systems in a gate-defined double quantum dot in a semiconductor nanowire. We show that current spectroscopy of inelastic transitions between the two quantum dots can be used as an experimental probe of the confined phonon environment. The resulting discrete peak structure in the measurements is explained by theoretical modeling of the confined phonon mode spectrum, where the piezoelectric coupling is of crucial importance.Comment: 4 pages, 4 figures; final versio

Zero-Phonon Line Broadening and Satellite Peaks in Nanowire Quantum Dots: The Role of Piezoelectric Coupling

We investigate the influence of the one-dimensional character of the phonon modes in a catalytically grown GaAs nanowire on the absorption spectrum of an embedded quantum dot, focusing on the contribution from the piezoelectric coupling. In general, the reduced dimensionality of the phonons leads to spectral side peaks and a zero-phonon line broadening due to the energetically lowest (acoustic) phonon mode. While the deformation potential predominantly couples to radial modes, the piezoelectric interaction can also couple strongly to modes of axial character, leading to additional absorption features. The contribution of the piezoelectric coupling to the zero-phonon line is negligible.Comment: 4 pages, 5 figures, to appear in Physica Status Solidi B (simulation parameters and figures changed, minor changes in text

Specific glial populations regulate hippocampal morphogenesis

The hippocampus plays an integral role in spatial navigation, learning and memory, and is a major site for adult neurogenesis. Critical to these functions is the proper organization of the hippocampus during development. Radial glia are known to regulate hippocampal formation, but their precise function in this process is yet to be defined. We find that in Nuclear Factor I b (Nfib)-deficient mice, a subpopulation of glia from the ammonic neuroepithelium of the hippocampus fail to develop. This results in severe morphological defects, including a failure of the hippocampal fissure, and subsequently the dentate gyrus, to form. As in wild-type mice, immature nestin-positive glia, which encompass all types of radial glia, populate the hippocampus in Nfib-deficient mice at embryonic day 15. However, these fail to mature into GLAST- and GFAP-positive glia, and the supragranular glial bundle is absent. In contrast, the fimbrial glial bundle forms, but alone is insufficient for proper hippocampal morphogenesis. Dentate granule neurons are present in the mutant hippocampus but their migration is aberrant, likely resulting from the lack of the complete radial glial scaffold usually provided by both glial bundles. These data demonstrate a role for Nfib in hippocampal fissure and dentate gyrus formation, and that distinct glial bundles are critical for correct hippocampal morphogenesis