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

Will I be Able to Understand My Mentee? Examining the Potential Risk of the Dominant Culture Mentoring Marginalized Youth

Most people would agree they want to live in a world where every child has what he or she needs to thrive and grow into a healthy and productive adult. It is estimated that 5,000 mentoring programs serve 3,000,000 youth in the United States alone (DuBois, Portillo, Rhodes, Silverthorn, & Valentine, 2011). In many of these programs, a majority of the mentors are matched with a mentee who comes from a culture and community they know very little about. Many of the youth development programs that were founded and implemented by people of the perceived dominant culture represent their values and cultural experience. To look more deeply into this, my primary research included seven one-on-one interviews with experienced youth workers, most who currently work at a community or site-based mentoring program. This article is a summary of their responses and reflections on the potential risks involved in matching across culture and considers how we might work together to mitigate these risks for the youth we serv

Statistical inference on interacting particle systems with applications to cancer biology

Interacting particle is a mathematical framework which allows for condensed and elegant modelling of complex phenomena undergoing both deterministic and random dynamics. While there are several ways to formulate an interacting particle system, this thesis focuses on modelling such dynamics using stochastic differential equations. The application in mind is describing the in vitro population dynamics of cancer cells.The introductory portion of the thesis presents the necessary mathematical and biological context, and formulate a model that is subsequently studied in the appended research papers. In the first of three papers, we introduce a novel method of inferring the diffusive properties in such systems based on a higher order numerical approximation of the underlying stochastic differential equations. In the second paper, we model the effect of cell-to-cell interactions, and conduct inference on this model using microscopy data. The third and last paper concerns modelling how the spatial distribution of the cell population effect the division rate, and apply our theoretical results to microscopy data.Put together, the three papers present a cohesive package on modelling and inference strategies one can use when tackling some of the most challenging problems in mathematical biology

Statistical Inference on Interacting Particle Systems

Interacting particle systems, and more specifically stochastic dynamical systems, is a mathematical framework which allows for condensed and elegant modelling of complex phenomena undergoing both deterministic and random dynamics. This thesis is concerned with the topic of statistical inference on large systems of interacting particles, with the specific application of in vitro migration of cancer cells. In the first of two papers appended with this thesis, we introduce a novel method of inference based on a higher order numerical approximation of the underlying stochastic differential equations. In the second paper, we formulate a model for glioblastoma cell migration, and conduct inference on this model using microscopy data. This regression shows promising results in its predictive power

The Relationship Between Undergraduate Research Training Programs and Motivational Resources for Underrepresented Minority Students in STEM: Program Participation, Self-efficacy, a Sense of Belonging, and Academic Performance

Although calls for a more diverse workforce in biomedical fields have been widespread, racial and ethnic gaps in biomedical degree attainment persist. In order to succeed, URM STEM students must persevere despite numerous challenges and stay continuously motivated on the long road to degree attainment in biomedical disciplines. Past higher education research has identified two key self-appraisals, a sense of belonging and self-efficacy, as crucial for student success. These beliefs, which can serve as motivational resources for students, include students\u27 convictions about whether they are a valued member of their academic community and whether they have what it takes to succeed in their discipline. This study explored how participation in an undergraduate research training program and students\u27 motivational resources may be shaping their academic performance and thus contributing to their successful completion of undergraduate biomedical degrees. The study also dissected program participation into five components and explored whether a sense of belonging or self-efficacy played a mediational role in the relationship between program participation and academic performance for URM STEM students. Single and multiple linear regression analyses were used and results indicated significant links between overall program participation and both motivational resources as well as significant connections between various program components and these self-perceptions. No significant relationship surfaced between overall program participation and academic performance but in a multiple regression analysis, research dosage was linked to performance for students in the study. Additionally, no significant connection was found between the motivational resources and academic performance and thus, the mediational role of a sense of belonging and self-efficacy in the relationship between program participation and performance could not be tested

Will I be Able to Understand My Mentee? Examining the Potential Risk of the Dominant Culture Mentoring Marginalized Youth

Most people would agree they want to live in a world where every child has what he or she needs to thrive and grow into a healthy and productive adult. It is estimated that 5,000 mentoring programs serve 3,000,000 youth in the United States alone (DuBois, Portillo, Rhodes, Silverthorn, & Valentine, 2011). In many of these programs, a majority of the mentors are matched with a mentee who comes from a culture and community they know very little about. Many of the youth development programs that were founded and implemented by people of the perceived dominant culture represent their values and cultural experience. To look more deeply into this, my primary research included seven one-on-one interviews with experienced youth workers, most who currently work at a community or site-based mentoring program. This article is a summary of their responses and reflections on the potential risks involved in matching across culture and considers how we might work together to mitigate these risks for the youth we serv

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

Plant response to planter induced edaphic factors with conservation tillage

The continuing trend towards no-till crop production places considerable emphasis on the planter to create a suitable environment for plant growth;The effects of plant residue cover and soil physical conditions associated with conservation tillage systems, were assessed in relation to emergence and early growth of corn (Zea mays L.) and winter wheat (Triticum aestivum);Increasing the residue-free area above the seed from 0 to 16 cm resulted in higher soil temperatures and improved early growth of corn at normal planting depths. Shallower planting helped offset the depressive effects of complete residue cover;Two types of grain drills were considered to be less effective than a unit planter with respect to seed placement and resulting soil conditions after planting, but because of good soil moisture conditions, emergence and early growth of winter wheat was similar for all planting methods;Increasing the vertical load on two styles of press-wheels from 215 to 645 N often increased the soil bulk density in the seed zone, but with adequate soil moisture, this had little effect on plant growth. Planter press-wheels may have a greater effect on early plant growth under drier conditions or on less well structured soils;A study conducted in the growth chamber demonstrated that residue cover can improve emergence, early growth, and water use efficiency of corn when soil moisture is limiting. Bulk densities exceeding 1.25 Mg/m(\u273) had the greatest effect on increasing soil moisture loss through evaporation and on reducing plant growth when soil moisture contents approached \u27field capacity\u27

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