Effective Hamiltonians for some highly frustrated magnets

In prior work, the authors developed a method of degenerate perturbation theory about the Ising limit to derive an effective Hamiltonian describing quantum fluctuations in a half-polarized magnetization plateau on the pyrochlore lattice. Here, we extend this formulation to an arbitrary lattice of corner sharing simplexes of $q$ sites, at a fraction $(q-2k)/q$ of the saturation magnetization, with $0<k<q$. We present explicit effective Hamiltonians for the examples of the checkerboard, kagome, and pyrochlore lattices. The consequent ground states in these cases for $k=1$ are also discussed.Comment: 10 pages, 2 figures,. Conference proceedings for Highly Frustrated Magnetism 200

Witnessing history: a personal view of half a century in public health

Former Chief Medical Officer Sir Kenneth Calman recently celebrated 50 years in medicine. It was a period which saw the evolution of the public health agenda from communicable diseases to diseases of lifestyle, the change from a hospital-orientated health service to one dominated by community-based services, and the increasing recognition of inequalities as a major determinant of health. This paper documents selected highlights from his career including the Aberdeen typhoid outbreak, AIDS, bovine spongiform encephalopathy, foot and mouth disease, radioactive fallout, the invention of computerised tomography and magnetic resonance imaging, and draws parallels between the development of the modern understanding of public health and the theoretical background to the science 100 years earlier

Abelianization of First Class Constraints

We show that a given set of first class constraints becomes abelian if one maps each constraint to the surface of other constraints. There is no assumption that first class constraints satisfy a closed algebra. The explicit form of the projection map is obtained at least for irreducible first class constraints. Using this map we give a method to obtain gauge fixing conditions such that the set of abelian first class constraints and gauge fixing conditions satisfy the symplectic algebra.Comment: To appear in PL

Lymphohaematopoietic malignancies in Scottish military veterans: Retrospective cohort study of 57,000 veterans and 173,000 non-veterans

Background: Lymphohaematopoietic malignancies are common in the general population. There have been concerns that military service may be associated with increased risk as a result of occupational exposures. To date, few studies have demonstrated an increased risk, although a disability pension is payable to veterans who were present at nuclear tests and who develop leukaemia (other than chronic lymphocytic leukaemia). The aim of the study was to utilise data from the Scottish Veterans Health Study to examine the risk of lymphohaematopoietic malignancy following military service in a large national cohort of veterans. Methods: Retrospective cohort study of 57,000 veterans and 173,000 non-veterans born between 1945 and 1985 matched for age, sex and area of residence, adjusted for areal deprivation and followed up for up to 30 years, using Cox proportional hazard models to compare the risk of lymphohaematopoietic malignancy overall, by diagnosis and by sex and birth cohort. Results: We found no statistically significant difference in risk between veterans and non-veterans either for all leukaemias (Cox proportional hazard ratio 1.03, 95% confidence intervals 0.84–1.27, p = 0.773), Hodgkin lymphoma (hazard ratio 1.19, 95% confidence intervals 0.87–1.61, p = 0.272) or for non-Hodgkin lymphoma (hazard ratio 0.86, 95% confidence intervals 0.71–1.04, p = 0.110). Conclusion: Our findings provide reassurance that service in the UK Armed Forces is not associated with increased risk of lymphohaematopoietic malignancy

Spin relaxation signature of colossal magnetic anisotropy in platinum atomic chains

Recent experimental data demonstrate emerging magnetic order in platinum atomically thin nanowires. Furthermore, an unusual form of magnetic anisotropy -- colossal magnetic anisotropy (CMA) -- was earlier predicted to exist in atomically thin platinum nanowires. Using spin dynamics simulations based on first-principles calculations, we here explore the spin dynamics of atomically thin platinum wires to reveal the spin relaxation signature of colossal magnetic anisotropy, comparing it with other types of anisotropy such as uniaxial magnetic anisotropy (UMA). We find that the CMA alters the spin relaxation process distinctly and, most importantly, causes a large speed-up of the magnetic relaxation compared to uniaxial magnetic anisotropy. The magnetic behavior of the nanowire exhibiting CMA should be possible to identify experimentally at the nanosecond time scale for temperatures below 5 K. This time-scale is accessible in e.g., soft x-ray free electron laser experiments.Comment: 9 pages, 3 figure

Supersymmetric Quantum Mechanics for String-Bits

We develop possible versions of supersymmetric single particle quantum mechanics, with application to superstring-bit models in view. We focus principally on space dimensions $d=1,2,4,8$, the transverse dimensionalities of superstring in $3,4,6,10$ space-time dimensions. These are the cases for which ``classical'' superstring makes sense, and also the values of $d$ for which Hooke's force law is compatible with the simplest superparticle dynamics. The basic question we address is: When is it possible to replace such harmonic force laws with more general ones, including forces which vanish at large distances? This is an important question because forces between string-bits that do not fall off with distance will almost certainly destroy cluster decomposition. We show that the answer is affirmative for $d=1,2$, negative for $d=8$, and so far inconclusive for $d=4$.Comment: 17 pages, Late

Disk-Like Structure in the Semi-Regular Pulsating Star, X Her

The author reports a result of an interferometric observation of the semiragular pulsating star with an unusual narrow molecular line profile, X Her, in the CO J=1-0 line with the Berkeley-Illinois-Maryland array. In the CO spectrum, a double-component profile (including narrow and broad components) is seen as reported by previous observations. The narrow component consists of two spiky peaks. The spatial structure of the board component shows bipolar shape, and that of the narrow component shows an elliptical/spherical shape. The two peaks in the narrow component show a systematic difference in the integrated intensity map. The kinematical and geometrical properties of the narrow component are reminiscent of a Keplerian rotating disk with the central mass of 0.9 M_sun, though an interpretation by an expansion disk seems to be more natural. A secondary bipolar flow instead of the disk cannot be fully excluded as an interpretation of the narrow line.Comment: 12 pages, 4 figues, accepted for publication in Ap

The winter habits of plants

Citation: Bergman, Herbert F. The winter habits of plants. Senior thesis, Kansas State Agricultural College, 1905.Morse Department of Special CollectionsIntroduction: In climates there is a period at some time of the year when plants cannot continue to live in an active state, but are required, by environmental conditions, to assume a form that will enable them to live through the unfavorable period. Whether a plant must pass through a period of cold, unfavorable to plant activity, or through a periodic drouth, the methods of meeting both these adverse conditions are the same. Since, in the temperate zone, it is the cold against which the plants must protect themselves, the forms assumed by them for protection during the winter are called their winter habits. If one should take a stroll through the fields or woods in the fall, he would notice that all plants do not succumb to the cold at the same time. Some plants cease activity at the "first suggestion of cold, while others continue through a. long succession of frosts before they perish. For example, such trees as the Maple, Boxelder, and Ash shed their leaves early, while cottonwood, elms and oaks cone somewhat later; many oaks retaining their leaves throughout the winter, shedding them early the following spring. Other plants yet, such as conifers, mosses, liver-orts and lichens, live through the winter with no apparent change. Between the group of plants which are killed by the winter, and the group which survive without apparent change in outward forms, stand the deciduous plants which cast their leaves and the herbaceous plants with thickened underground stems or roots wherein the living substance, withdrawn from the leaves and stems, is able to survive the winter. The degree of cold necessary to cruse the death of any plant depends upon the nature of the protoplasm, i, e. the ability of the protoplasts of that kind of plant to withstand adverse conditions, and also upon the stage of development or activity of the plant at the time it is subjected to the cold

The curious case of culture in international business:an autoethnographic study

Abstract. The topic of this thesis is how culture and intercultural communication manifest themselves in today’s business environments. This thesis reflects on the relevancy and accuracy of the prominent intercultural communication theories of Edward T. Hall (1989) and Geert Hofstede (1986; 2010) in the light of the personal experiences of individuals who are currently working in international business environments. The theories of Hall and Hofstede are regarded by some as the key theories of intercultural communication, which is why these two were chosen as the specific theoretical focus for this thesis. The theories have since received some criticism for taking too many liberties in generalizing entire populations of people based on the perceived prominent aspects of different cultures (e.g. hierarchy of Japanese culture and individualism of American culture). The research method used in this thesis is analytic autoethnography. This choice of research method not only influences the language used in this thesis but also the structure of the paper. The data of this thesis consists of the personal experiences of myself and three interviewees. These personal experiences are examined in the light of the theories of Hall and Hofstede in an attempt to discover how well the theories reflect the real-life experiences of people working in the business world, and to offer the reader insights into how culture manifests itself in business environments. The data used in this thesis shows that while the theories can still be considered somewhat relevant in the intercultural business environments of today, the relevancy seems limited to very specific instances. Additionally, it seems that reliance on the theoretical framework for cultures which the theories provide may even hinder actual intercultural communication situations in the business world. The data also shows that other forms of culture — such as organization culture and profession culture — are perhaps more important than national culture in business contexts, something which the theories of Hall and Hofstede do not seem to address adequately. This thesis does not definitively answer how intercultural communication should be addressed now or in the future. However, this thesis aims to provide the reader with ideas and insights into intercultural communication in real business environments.Tiivistelmä. Tämän opinnäytteen aihe on, kuinka kulttuuri ja interkulttuurinen kommunikaatio ilmentyvät nykypäivän bisnesympäristöissä. Tässä opinnäytteessä tutkitaan, kuinka hyvin Edward T. Hallin (1989) ja Geert Hofsteden (1986; 2010) merkittävät teoriat interkulttuurisesta kommunikaatiosta vastaavat kansainvälisissä bisnesympäristöissä työskentelevien henkilöiden omia kokemuksia. Aikaisemmassa aiheeseen liittyvässä kirjallisuudessa Hallin ja Hofsteden teorioita interkulttuurisesta kommunikaatiosta pidetään merkittävinä, minkä takia nämä kaksi teoriaa valittiin tämän opinnäytteen fokukseksi. Näitä teorioita on kritisoitu muun muassa siitä, että ne yleistävät liian vapaasti kokonaisia väestöryhmiä näennäisesti erilaisten kulttuuripiirteiden perusteella (esimerkiksi hierarkkisuus Japanissa ja individualismisuus Amerikassa). Tässä opinnäytteessä käytetty tutkimusmetodi on analyyttinen autoetnografia. Tutkimusmetodin valinta on vaikuttanut tutkimuksessa sekä tutkimuksen kirjoitustyyliin että opinnäytteen rakenteeseen. Tutkimuksessa käytetty aineisto koostuu sekä tutkijan omista että kolmen haastateltavan henkilökohtaisista kokemuksista. Näitä henkilökohtaisia kokemuksia tarkastellaan Hallin ja Hofsteden teorioiden avulla. Tutkimuksen tavoitteena on selvittää, kuinka hyvin nämä teoriat vastaavat aineistossa ilmentyviä tosielämän henkilökohtaisia kokemuksia ja kuinka kulttuuri ilmentyy bisnesympäristöissä. Aineistosta ilmenee, että vaikka teorioissa esiintyykin yhtäläisyyksiä todellisten henkilökohtaisten kokemuksien kanssa, teorioiden hyödyt rajoittuvat kuitenkin vain tietynlaisiin tilanteisiin. Lisäksi aineistosta ilmenee, että liiallinen tukeutuminen teorioissa esitettyihin kulttuurisiin raameihin voi jopa osoittautua haitalliseksi todellisissa interkulttuurisissa kommunikaatiotilanteissa. Aineistosta käy myös ilmi, että bisneskonteksteissa kulttuurin muut muodot, kuten organisaatiokulttuuri ja ammattikulttuuri, ovat mahdollisesti olennaisempia kuin kansalliskulttuuri, mitä Hallin ja Hofsteden teoriat eivät käsittele tarpeeksi kattavasti. Tämä opinnäytetyö ei kykene vastaamaan siihen, kuinka interkulttuurista kommunikaatiota pitäisi käsitellä teoreettisesti nyt tai tulevaisuudessa. Työn tavoitteena on kuitenkin tarjota lukijalle ajatuksia ja näkemyksiä siitä, kuinka interkulttuurinen kommunikaatio toimii kansainvälisissä bisnesympäristöissä