996 resultados para Hubbard, Charles Wesley, 1810-1903.
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A strong-coupling expansion for the Green's functions, self-energies, and correlation functions of the Bose-Hubbard model is developed. We illustrate the general formalism, which includes all possible (normal-phase) inhomogeneous effects in the formalism, such as disorder or a trap potential, as well as effects of thermal excitations. The expansion is then employed to calculate the momentum distribution of the bosons in the Mott phase for an infinite homogeneous periodic system at zero temperature through third order in the hopping. By using scaling theory for the critical behavior at zero momentum and at the critical value of the hopping for the Mott insulator–to–superfluid transition along with a generalization of the random-phase-approximation-like form for the momentum distribution, we are able to extrapolate the series to infinite order and produce very accurate quantitative results for the momentum distribution in a simple functional form for one, two, and three dimensions. The accuracy is better in higher dimensions and is on the order of a few percent relative error everywhere except close to the critical value of the hopping divided by the on-site repulsion. In addition, we find simple phenomenological expressions for the Mott-phase lobes in two and three dimensions which are much more accurate than the truncated strong-coupling expansions and any other analytic approximation we are aware of. The strong-coupling expansions and scaling-theory results are benchmarked against numerically exact quantum Monte Carlo simulations in two and three dimensions and against density-matrix renormalization-group calculations in one dimension. These analytic expressions will be useful for quick comparison of experimental results to theory and in many cases can bypass the need for expensive numerical simulations.
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The Davoser Hochschulkurse took place for the first time in 1928. Mainly university teachers from Germany, France, Switzerland (perhaps elsewhere) offered lectures to students recovering from tuberculosis at the health resort in the Swiss mountains. The lecturers were accommodated at the Grand Hotel Curhaus, where the lectures also took place.
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Aim Frail older people typically suffer several chronic diseases, receive multiple medications and are more likely to be institutionalized in residential aged care facilities. In such patients, optimizing prescribing and avoiding use of high-risk medications might prevent adverse events. The present study aimed to develop a pragmatic, easily applied algorithm for medication review to help clinicians identify and discontinue potentially inappropriate high-risk medications. Methods The literature was searched for robust evidence of the association of adverse effects related to potentially inappropriate medications in older patients to identify high-risk medications. Prior research into the cessation of potentially inappropriate medications in older patients in different settings was synthesized into a four-step algorithm for incorporation into clinical assessment protocols for patients, particularly those in residential aged care facilities. Results The algorithm comprises several steps leading to individualized prescribing recommendations: (i) identify a high-risk medication; (ii) ascertain the current indications for the medication and assess their validity; (iii) assess if the drug is providing ongoing symptomatic benefit; and (iv) consider withdrawing, altering or continuing medications. Decision support resources were developed to complement the algorithm in ensuring a systematic and patient-centered approach to medication discontinuation. These include a comprehensive list of high-risk medications and the reasons for inappropriateness, lists of alternative treatments, and suggested medication withdrawal protocols. Conclusions The algorithm captures a range of different clinical scenarios in relation to potentially inappropriate medications, and offers an evidence-based approach to identifying and, if appropriate, discontinuing such medications. Studies are required to evaluate algorithm effects on prescribing decisions and patient outcomes.
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Objective: In Australian residential aged care facilities (RACFs), the use of certain classes of high-risk medication such as antipsychotics, potent analgesics, and sedatives is high. Here, we examined the prescribed medications and subsequent changes recommended by geriatricians during comprehensive geriatric consultations provided to residents of RACFs via videoconference. Design: This is a prospective observational study. Setting: Four RACFs in Queensland, Australia, are included. Participants: A total of 153 residents referred by general practitioners for comprehensive assessment by geriatricians delivered by video-consultation. Results: Residents’ mean (standard deviation, SD) age was 83.0 (8.1) years and 64.1% were female. They had multiple comorbidities (mean 6), high levels of dependency, and were prescribed a mean (SD) of 9.6 (4.2) regular medications. Ninety-one percent of patients were taking five or more medications daily. Of total medications prescribed (n=1,469), geriatricians recommended withdrawal of 9.8% (n=145) and dose alteration of 3.5% (n=51). New medications were initiated in 47.7% (n=73) patients. Of the 10.3% (n=151) medications considered as high risk, 17.2% were stopped and dose altered in 2.6%. Conclusion: There was a moderate prevalence of potentially inappropriate high-risk medications. However, geriatricians made relatively few changes, suggesting either that, on balance, prescription of these medications was appropriate or, because of other factors, there was a reluctance to adjust medications. A structured medication review using an algorithm for withdrawing medications of high disutility might help optimize medications in frail patients. Further research, including a broader survey, is required to understand these dynamics.
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Letters and documents of Philippson-Gottschalk family, primarily famly affairs.
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Jewish organization executive. Primarily autographs, photos, writings, speeches, and biographical material, collected by Bisno, relating to ca. 120 Jews who have attained prominence in American public life; together with papers (1923-32) from Congregation Talmud Torah of Los Angeles, letters (1928-37) relating to other Jewish organizations in Los Angeles, and 3 letters of Stephen S. Wise, dealing with the general Jewish situation in Europe in 1933 and with the question of Jewish participation in the 1936 Olympic games. Persons represented include Benjamin N. Cardozo, Abe Fortas, Felix Frankfurter, Henry Horner, Herbert H. Lehman, and Lewis L. Strauss.
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Collection consists of material from the administration, services, individual branches, and schools of the Workmen's Circle. The majority of the collection are publications of the Workmen's Circle relating to conventions and education. The collection also includes annual reports, newsletters, bulletins, and pamphlets.
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Contains Board of Directors minutes (1903, 1907), Executive Committee minutes (1907), Removal Committee minutes (1903-1917), Annual Reports (1910, 1913), Monthly Reports (1901-1919), Monthly Bulletins (1914-1915), studies of those removed, Bressler's "The Removal Work, Including Galveston," and several papers relating to the IRO and immigration. Financial papers include a budget (1914), comparative per capita cost figures (1909-1922), audits (1915-1918), receipts and expenditures (1918-1922), investment records, bank balances (1907-1922), removal work cash book (1904-1911), office expenses cash account (1903-1906), and the financial records of other agencies working with the IRO (1906). Includes also removal case records of first the Jewish Agricultural Society (1899-1900), and then of the IRO (1901-1922) when it took over its work, family reunion case records (1901-1904), and the follow-up records of persons removed to various cities (1903-1914). Contains also the correspondence of traveling agents' contacts throughout the U.S. from 1905-1914, among them Stanley Bero, Henry P. Goldstein, Philip Seman, and Morris D. Waldman.
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General Index Vol 13 Parts 1-6, pages 1-81
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Articles by Fuchs; letters to his son; obituaries.
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Tarkastelen pro gradu -tutkielmassani naiskysymystä Seitsemännen päivän adventtikirkon oppiäiti Ellen Whiten (1827 1915) terveysopetuksessa. White tunnetaan ennen kaikkea näyistään, joiden välityksellä hän koki saavansa Jumalalta hyvinvointiin liittyviä ohjeita. White kirjoitti näkyjensä innoittama terveysoppaita ja julisti pääasiassa Yhdysvalloissa yli 70 vuotta. Päälähteenäni ovat kaksi Whiten omaelämäkertaa vuosilta 1880 ja 1915 sekä 83 artikkelia, jotka hän julkaisi adventistien johtavassa terveyslehdessä, Health Reformerissa, vuosina 1866 1878. Tutkimuskysymykseni ovat, miksi White osoitti lähes kaiken terveyteen liittyvän opetuksensa naisille ja miten hän ymmärsi terveyden osana naisen roolia ja tehtäviä. Tulkintani mukaan White julisti naisille, sillä hän uskoi, että naisen asema oli selkeytettävä. Yhdysvallat teollistui ja kaupungistui nopeasti 1800-luvulla, mikä aiheutti naisille taloudellisia, sosiaalisia ja terveyteen liittyviä ongelmia. Lisäksi toinen suuri herätys (1800 1830) synnytti keskustelua naisen roolista. Monet kirkot antoivat naisille luvan esimerkiksi saarnaamiseen, mutta Yhdysvalloissa vahvistui samaan aikaan myös käsitys naisesta kodin uskonnollisena johtajana. Ymmärrän, että Whiten mukaan ratkaisu naisen sekavaan asemaan oli terveys. Uskon, että Whiten mukaan nainen pystyi ottamaan oman paikkansa yhteiskunnassa, mikäli hän pysyi terveenä ja oppi tuntemaan terveyden periaatteet. Toisaalta White sai vaikutteita naisten yhteiskunnallisten oikeuksien puolustajilta. He ajattelivat, että vain koulutettu ja terve nainen kykeni vapautumaan avioliitosta. Toisaalta White oli naisasianaisia maltillisempi. Hän ymmärsi, että vain terve ja terveyskoulutuksen saanut nainen saattoi olla hyvä äiti. Ellen White osallistui terveysopetuksellaan keskusteluun myös naisen uskonnollisesta roolista. White oli itse kiertelevä terveyssaarnaaja. Silti hän ymmärsi, että muiden naisten kutsumus oli olla terve ja koulutettu äiti. White korosti äitien pyhyyttä luultavasti siksi, että hän pyrki turvaamaan oman auktoriteettiasemansa Adventtikirkossa. White myös luultavasti ymmärsi roolinsa ja tehtävänsä poikkeuksellisiksi ja arvosti vilpittömästi äitiyttä. Whiten mukaan äidin tehtävä oli kasvattaa terveitä ja moraalisia kansalaisia. Tehtävän arvon hän perusteli aikansa tieteellisillä teorioilla. White korosti luonnontieteilijä Charles Darwinin (1809 1882) evoluutioteorian mukaisesti, että äidin velvollisuus oli siirtää lapsilleen hyvä terveys. Käsityksensä terveyden ja moraalin suhteesta hän selitti frenologialla, jonka mukaan ihmisen elämäntavat vaikuttivat hänen luonteenpiirteisiinsä. White oli myös todennäköisesti kiinnostunut sosiaalitieteilijä Herbert Spencerin (1820 1903) ajatuksista, joiden mukaan kansalaisten kehittyessä myös yhteiskunta jalostui yhä paremmaksi. Vaikka White perusteli opetustaan modernilla tieteellä, hän oli ennen kaikkea uskonnollinen julistaja. Hän kuului 1840-luvulla herätyssaarnaaja William Millerin (1782 1849) liikkeeseen, jonka jäsenet uskoivat, että Jumala tuhoaa Yhdysvallat viimeisellä tuomiolla, mikäli kansan moraalin tila ei nopeasti kohene. Millerin liikkeen painotukset säilyivät Adventtikirkossa, joka perustettiin vuonna 1863. Siten White ymmärsi, ettei äiti ollut vastuussa vain perheensä ja kansansa maallisesta hyvinvoinnista vaan myös heidän pelastuksestaan. Whiten käsitys äidistä on mielestäni ristiriitainen. White antoi äideille paljon valtaa, mutta myös suuren vastuun. Hän korosti äitien arvokkuutta, mutta toisaalta he eivät olleet hänen mukaansa korvaamattomia. White ei myöskään huomioinut naisia, jotka eivät olleet äitejä.
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We report our findings on the quantum phase transitions in cold bosonic atoms in a one-dimensional optical lattice using the finite-size density-matrix renormalization-group method in the framework of the extended Bose-Hubbard model. We consider wide ranges of values for the filling factors and the nearest-neighbor interactions. At commensurate fillings, we obtain two different types of charge-density wave phases and a Mott insulator phase. However, departure from commensurate fillings yields the exotic supersolid phase where both the crystalline and the superfluid orders coexist. In addition, we obtain the signatures for the solitary waves and the superfluid phase.
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We have obtained the quantum phase diagram of a one-dimensional superconducting quantum dot lattice using the extended Bose-Hubbard model for different commensurabilities. We describe the nature of different quantum phases at the charge degeneracy point. We find a direct phase transition from the Mott insulating phase to the superconducting phase for integer band fillings of Cooper pairs. We predict explicitly the presence of two kinds of repulsive Luttinger liquid phases, besides the charge density wave and superconducting phases for half-integer band fillings. We also predict that extended range interactions are necessary to obtain the correct phase boundary of a one-dimensional interacting Cooper system. We have used the density matrix renormalization group method and Abelian bosonization to study our system.
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We generalize the mean-field theory for the spinless Bose-Hubbard model to account for the different types of superfluid phases that can arise in the spin-1 case. In particular, our mean-field theory can distinguish polar and ferromagnetic superfluids, Mott insulator, that arise at integer fillings at zero temperature, and normal Bose liquids into which the Mott insulators evolve at finite temperatures. We find, in contrast to the spinless case, that several of the superfluid-Mott insulator transitions are of first order at finite temperatures. Our systematic study yields rich phase diagrams that include first-order and second-order transitions and a variety of tricritical points. We discuss the possibility of realizing such phase diagrams in experimental systems.