6,573 research outputs found
New and noteworthy records of lichens and allied fungi from Sakhalin Island, Russian Far East, II
Eopyrenula intermedia is a new finding for Eurasia. Fauriea orientochinensis and Hafellia subnexa are reported for the first time for Russia, from Sakhalin Island. A further seventeen species are noteworthy for Sakhalin Island, including two species new to the Russian Far East and five species new to the southern part of the region
Splitting and merging an elongated Bose-Einstein condensate at finite temperature
We analyze coherence effects during the splitting of a quasi one-dimensional
condensate into two spatially separated ones and their subsequent merging into
a single condensate. Our analysis takes into account finite-temperature
effects, where phase fluctuations play an important role. We show that, at
zero-temperature, the two split condensates can be merged into a single one
with a negligible phase difference. By increasing temperature to a finite value
below the critical point for condensation (), i.e., , a
considerable enhancement of phase and density fluctuations appears during the
process of splitting and merging. Our results show that if the process of
splitting and merging is sufficiently adiabatic, the whole process is quite
insensitive to phase fluctuations and even at high temperatures, a single
condensate can be produced.Comment: 8 pages, 6 figure
Hadron multiplicities in e+e- annihilation with heavy primary quarks
The multiple hadron production in the events induced by the heavy primary
quarks in annihilation is reconsidered with account of corrected
experimental data. New value for the multiplicity in events is
presented on the basis of pQCD estimates.Comment: 16 pages, 6 figures. Version accepted for publication in EPJ
Comparing loneliness in England and the United States, 2014-2016: Differential item functioning and risk factor prevalence and impact
The purpose of this study is to compare mean levels of loneliness, and correlates of loneliness, among older adults in the U.S. and England. Comparisons are conducted after attending to comparability of the loneliness measure between countries based on tests for discriminatory capacity and differential item functioning of the 3-item UCLA Loneliness Scale. Cross-sectional data from the 2015-16 wave of the National Social Life, Health and Aging Project (NSHAP) and the 2014-2015 wave of the English Longitudinal Study on Ageing (ELSA) were analyzed using graded item response models and multiple indicators and multiple causes (MIMIC) models. Risk factors included demographic variables, health characteristics, and social characteristics that were harmonized across surveys. Because of differences in the racial-ethnic composition of the U.S. and England, analyses were limited to white respondents (NÂ =Â 2624 in NSHAP; NÂ =Â 6639 in ELSA). Only respondents born 1925-1965 were included in analyses. Discriminatory capacity was evident in each item being able to distinguish a lonely from a nonlonely individual. Differential item functioning (DIF) was evident in country differences in the likelihood of endorsing the "lack companionship" item at a given level of trait loneliness, and in DIF among marital status, education, and gender subgroups that were comparable across countries. Overall loneliness levels are equivalent in England and the U.S. Risk factor impact did not differ between countries, but differences in risk factor prevalence between countries combined to produce a net result of slightly lower mean levels of loneliness in older adults in England than in the U.S. after risk factor adjustment. The fact that the impact of risk factors were similar across countries suggests that evidence of successful interventions in one country could be leveraged to accelerate development of effective interventions in the other
Noise Thermometry with Two Weakly Coupled Bose-Einstein Condensates
Here we report on the experimental investigation of thermally induced
fluctuations of the relative phase between two Bose-Einstein condensates which
are coupled via tunneling. The experimental control over the coupling strength
and the temperature of the thermal background allows for the quantitative
analysis of the phase fluctuations. Furthermore, we demonstrate the application
of these measurements for thermometry in a regime where standard methods fail.
With this we confirm that the heat capacity of an ideal Bose gas deviates from
that of a classical gas as predicted by the third law of thermodynamics.Comment: 4 pages, 4 figure
Nonlinear transport of Bose-Einstein condensates through mesoscopic waveguides
We study the coherent flow of interacting Bose-condensed atoms in mesoscopic
waveguide geometries. Analytical and numerical methods, based on the mean-field
description of the condensate, are developed to study both stationary as well
as time-dependent propagation processes. We apply these methods to the
propagation of a condensate through an atomic quantum dot in a waveguide,
discuss the nonlinear transmission spectrum and show that resonant transport is
generally suppressed due to an interaction-induced bistability phenomenon.
Finally, we establish a link between the nonlinear features of the transmission
spectrum and the self-consistent quasi-bound states of the quantum dot.Comment: 23 pages, 16 figure
Report of the Subgroup on Alternative Models and New Ideas
We summarize some of the work done by the P3 subgroup on Alternative Models
and New Ideas. The working group covered a broad range of topics including a
constrained Standard Model from an extra dimension, a discussion of recent
ideas addressing the strong CP problem, searches for doubly charged higgs
bosons in e gamma collisions, and an update on discovery limits for extra
neutral gauge bosons at hadron colliders. The breadth of topics reflects the
many ideas and approaches to physics beyond the Standard Model.Comment: 10 pages, 5 figures. Contributed to the APS/DPF/DPB Summer Study on
the Future of Particle Physics (Snowmass 2001), Snowmass, Colorado, 30 Jun -
21 Jul 200
Circulating calcitonin and carcinoembryonic antigen m-RNA detected by RT-PCR as tumour markers in medullary thyroid carcinoma
Detection of local relapse or metastasis in medullary thyroid carcinoma (MTC) continue to pose a major diagnostic challenge. Besides established diagnostic studies such as serum calcitonin (CT) and carcinoembryonic antigen (CEA), molecular detection of circulating tumour cells may be an additional diagnostic tool for the early detection of disease recurrence. We performed reverse transcription-polymerase chain reaction (RT-PCR) on blood samples from patients diagnosed with MTC disease using primers specific for CT and CEA, respectively. CT mRNA was not detectable in peripheral blood of all patients with MTC (n = 11) and all controls (n = 32). CEA mRNA was significantly more often detected patients with MTC (72.7%) than in controls (34.4%; p = 0.038; Fisher exact test). With an example of a patient with MTC and massive tumour mass in the neck we demonstrate the failure of detection of CT mRNA over a period of 6 months, whereas CEA mRNA could be detected in peripheral blood of this patient. As a consequence, CT mRNA detected by RT-PCR in the peripheral blood can not be recommended as a tumour marker in MTC. However, the use of carcinoembryonic mRNA may provide a significant improvement in diagnosis of recurrent disease in MTC. © 2001 Cancer Research Campaign   http://www.bjcancer.co
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