2,875 research outputs found
Decoherence as attenuation of mesoscopic echoes in a spin-chain channel
An initial local excitation in a confined quantum system evolves exploring
the whole system, returning to the initial position as a mesoscopic echo at the
Heisenberg time. We consider a two weakly coupled spin chains, a spin ladder,
where one is a quantum channel while the other represents an environment. We
quantify decoherence in the quantum channel through the attenuation of the
mesoscopic echoes. We evaluate decoherence rates for different ratios between
sources of amplitude fluctuation and dephasing in the inter-chain interaction
Hamiltonian. The many-body dynamics is seen as a one-body evolution with a
decoherence rate given by the Fermi golden rule.Comment: 12 pages, 7 figure
Quantum parallelism as a tool for ensemble spin dynamics calculations
Efficient simulations of quantum evolutions of spin-1/2 systems are relevant
for ensemble quantum computation as well as in typical NMR experiments. We
propose an efficient method to calculate the dynamics of an observable provided
that the initial excitation is "local". It resorts a single entangled pure
initial state built as a superposition, with random phases, of the pure
elements that compose the mixture. This ensures self-averaging of any
observable, drastically reducing the calculation time. The procedure is tested
for two representative systems: a spin star (cluster with random long range
interactions) and a spin ladder.Comment: 5 pages, 3 figures, improved version of the manuscrip
Perfect state transfers by selective quantum interferences within complex spin networks
We present a method that implement directional, perfect state transfers
within a branched spin network by exploiting quantum interferences in the
time-domain. That provides a tool to isolate subsystems from a large and
complex one. Directionality is achieved by interrupting the spin-spin coupled
evolution with periods of free Zeeman evolutions, whose timing is tuned to be
commensurate with the relative phases accrued by specific spin pairs. This
leads to a resonant transfer between the chosen qubits, and to a detuning of
all remaining pathways in the network, using only global manipulations. As the
transfer is perfect when the selected pathway is mediated by 2 or 3 spins,
distant state transfers over complex networks can be achieved by successive
recouplings among specific pairs/triads of spins. These effects are illustrated
with a quantum simulator involving 13C NMR on Leucine's backbone; a six-spin
network.Comment: 5 pages, 3 figure
Development and Initial Validation of the Beliefs About Sexual Functioning Scale: A Gender Invariant Measure
The work was financially supported by the BIAL Foundation Fellowship (167/12) and by the Portuguese
Science Foundation (CPUP UID/PSI/00050/2013; FEDER/COMPETE2020 POCI-01-0145-FEDER-007294).Background: Past research on cognitive models of sexual functioning has focused on sexual beliefs as an important
vulnerability factor for sexual dysfunction. However, the existing measurements of sexual beliefs are lengthy and
entangle beliefs about sexual functioning with moral beliefs and ideas about sexuality. Furthermore, they have
female and male versions, which does not allow for sex comparisons or dyadic research with heterosexual couples.
Aim: To describe the development and validation of the Beliefs About Sexual Functioning Scale (BASEF), which
assesses beliefs about sexual functioning in men and women.
Methods: This study included two cross-sectional online studies with adults in heterosexual dyadic committed
and exclusive relationships. In study 1 (sample A, n ¼ 274, mean age ¼ 32.27 years; sample B, n ¼ 114, mean
age ¼ 30.6 years), the factorial validity of the BASEF was analyzed through an exploratory factor analysis with an
initial poll of 51 items, followed by a test of its structure in a confirmatory factor analysis. In study 2 (n ¼ 426,
mean age ¼ 31.5 years), the factorial equivalence of the BASEF was tested across sexes and its association with
total scores of sexual functioning was analyzed.
Outcome: The main outcome was a new instrument for measurement of beliefs about sexual functioning.
Results: In study 1, 15 items indicating 5 factors were retained. The structure was confirmed by confirmatory
factor analysis, establishing its factorial validity with the five factors aggregated in a second-order latent variable. In
study 2, the equivalence of the BASEF was demonstrated across sexes and its association with theoretically related
measurements, the International Index of Erectile Function and the Female Sexual Function Index, was supported.
Clinical Implications: This new measurement could be useful to evaluate clients and design interventions that
take into account similarity and discrepancy in sexual beliefs in couples, such as those interventions framed in
cognitive and systemic clinical models.
Strengths and Limitations: This study presents a new measurement of beliefs about sexual functioning suited
to address an equivalent set of beliefs for men and women. In future studies, the scale will be useful to compare
the unique role of these same beliefs in the sexual outcomes of men and women. One major limitation is the lack
of examination of the BASEF criterion validity with a clinical sample.
Conclusions: Results are indicative of a brief, valid, and reliable sex-invariant measurement of beliefs about
sexual functioning that enables testing of cognitive models of sexual functioning in men and women in clinical
and research settings.info:eu-repo/semantics/publishedVersio
Evaluation of the immunomodulatory activities of the probiotic strain lactobacillus fermentum UCO-979C
Lactobacillus fermentum UCO-979C, a strain isolated from a human stomach, was previously characterized by its potential probiotic properties. The UCO-979C strain displayed the ability to beneficially regulate the innate immune response triggered by Helicobacter pylori infection in human gastric epithelial cells. In this work, we conducted further in vitro studies in intestinal epithelial cells (IECs) and in vivo experiments in mice in order to characterize the potential immunomodulatory effects of L. fermentum UCO-979C on the intestinal mucosa. Results demonstrated that the UCO-979C strain is capable to differentially modulate the immune response of IECs triggered by Toll-like receptor 4 (TLR4) activation through the modulation of TLR negative regulators' expression. In addition, we demonstrated for the first time that L. fermentum UCO-979C is able to exert its immunomodulatory effect in the intestinal mucosa in vivo. The feeding of mice with L. fermentum UCO-979C significantly increased the production of intestinal IFN-γ, stimulated intestinal and peritoneal macrophages and increased the number of Peyer's patches CD4+ T cells. In addition, L. fermentum UCO-979C augmented intestinal IL-6, reduced the number of immature B220+CD24high B cells from Peyer's patches, enhanced the number of mature B B220+CD24low cells, and significantly increased intestinal IgA content. The results of this work revealed that L. fermentum UCO-979C has several characteristics making it an excellent candidate for the development of immunobiotic functional foods aimed to differentially regulate immune responses against gastric and intestinal pathogens.Fil: Garcia Castillo, Valeria. Tohoku University; Japón. Universidad de Concepción; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Komatsu, Ryoya. Tohoku University; JapónFil: Clua, Maria Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Indo, Yuhki. Tohoku University; JapónFil: Takagi, Michihiro. Tohoku University; JapónFil: Salva, Maria Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Islam, M. Aminul. Bangladesh Agricultural University; Bangladesh. Tohoku University; JapónFil: Alvarez, Gladis Susana. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Takahashi, Hideki. Tohoku University; JapónFil: Garcia Cancino, Apolinaria. Universidad de Concepción; ChileFil: Kitazawa, Haruki. Tohoku University; JapónFil: Villena, Julio Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Tohoku University; Japó
Insights into the metabolism of oleaginous Rhodococcus spp
Some species belonging to the Rhodococcus genus, such as Rhodococcus opacus, R. jostii, and R. wratislaviensis, are known to be oleaginous microorganisms, since they are able to accumulate triacylglycerols (TAG) at more than 20% of their weight (dry weight). Oleaginous rhodococci are promising microbial cell factories for the production of lipids to be used as fuels and chemicals. Cells could be engineered to create strains capable of producing high quantities of oils from industrial wastes and a variety of high-value lipids. The comprehensive understanding of carbon metabolism and its regulation will contribute to the design of a reliable process for bacterial oil production. Bacterial oleagenicity requires an integral configuration of metabolism and regulatory processes rather than the sole existence of an efficient lipid biosynthesis pathway. In recent years, several studies have been focused on basic aspects of TAG biosynthesis and accumulation using R. opacus PD630 and R. jostii RHA1 strains as models of oleaginous bacteria. The combination of results obtained in these studies allows us to propose a metabolic landscape for oleaginous rhodococci. In this context, this article provides a comprehensive and integrative view of different metabolic and regulatory attributes and innovations that explain the extraordinary ability of these bacteria to synthesize and accumulate TAG. We hope that the accessibility to such information in an integrated way will help researchers to rationally select new targets for further studies in the field.Fil: Alvarez, Héctor M.. Universidad Nacional de la Patagonia "San Juan Bosco". Instituto de Biociencias de la Patagonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biociencias de la Patagonia; ArgentinaFil: Herrero, O. Marisa. Universidad Nacional de la Patagonia "San Juan Bosco". Instituto de Biociencias de la Patagonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biociencias de la Patagonia; ArgentinaFil: Silva, Roxana A.. Universidad Nacional de la Patagonia "San Juan Bosco". Instituto de Biociencias de la Patagonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biociencias de la Patagonia; ArgentinaFil: Hernández, Martín A.. Universidad Nacional de la Patagonia "San Juan Bosco". Instituto de Biociencias de la Patagonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biociencias de la Patagonia; ArgentinaFil: Lanfranconi, Mariana Patricia. Universidad Nacional de la Patagonia "San Juan Bosco". Instituto de Biociencias de la Patagonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biociencias de la Patagonia; ArgentinaFil: Villalba, María Soledad. Universidad Nacional de la Patagonia "San Juan Bosco". Instituto de Biociencias de la Patagonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biociencias de la Patagonia; Argentin
Many-spin quantum dynamics during cross polarization in 8CB
We analyze theoretically and experimentally the quantum dynamics of a three-spin-1/2 system during cross polarization (CP). Our analysis takes into account a Hamiltonian behavior for a carbon C-13 coupled to two protons H-1 while the coupling to a spin bath is treated in the fast fluctuation approximation. This model is applied to the methylene and biphenyl groups of the smectic and nematic phases of the liquid crystal 4-n-octyl-4(´)-cyanobiphenyl (8CB). Experimental data from standard CP, combined with our theoretical results, allow us to separate the homonuclear H-1-H-1 and heteronuclear H-1-C-13 residual dipolar couplings. These values are in good agreement with those obtained by using a combination of CP under Lee-Goldburg conditions and standard CP data. A well differentiated relaxation behavior among the two phases seems to indicate that while the extreme narrowing approximation is appropriate for the nematic phase, the description of the smectic phase requires consideration of the slow-motion limit.Fil: Chattah, Ana Karina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Alvarez, Gonzalo Agustin. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Bariloche | Comisión Nacional de Energía Atómica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Bariloche; ArgentinaFil: Levstein, Patricia Rebeca. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Cucchietti, Fernando M.. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Pastawski, Horacio Miguel. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Raya, Jésus. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Hirschinger, Jérôme. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentin
Book Reviews
Book Reviews: Unconquerable Rebel: Robert W. Wilcox And Hawaiian Politics, 1880 - 1903 by Ernest Andrade, Jr.; Women And Children First: the Life And Times of Elsie Wilcox of Kaua'i by Judith Dean Gething Hughes; the Shipmans of East Hawai'i by Emmett Cahill; Shaping History: the Role of Newspapers In Hawai'i by Helen Geracimos Chapin; Waikiki 100 B.C. To 1900 A.D.: An Untold Story by George S. Kanahele; Surveying the Mahele: Mapping the Hawaiian Land Revolution by Riley M. Moffat And Gary L. Fitzpatrick; the Filipino Piecemeal Sugar Strike of 1924-1925 by John E. Reinecke; Sugar Water: Hawaii's Plantation Ditches by Carol Wilcox; Who Runs the University? the Politics of Higher Education In Hawaii, 1985 - 1992 by David Youn
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