1,624 research outputs found
Coherent control of population transfer between vibrational states in an optical lattice via two-path quantum interference
We demonstrate coherent control of population transfer between vibrational
states in an optical lattice by using interference between a one-phonon
transition at and a two-phonon transition at . The
and transitions are driven by phase- and amplitude-modulation of the
lattice laser beams, respectively. By varying the relative phase between these
two pathways, we control the branching ratio of transitions to the first
excited state and to the higher states. Our best result shows an improvement of
the branching ratio by a factor of 3.50.7. Such quantum control techniques
may find broad application in suppressing leakage errors in a variety of
quantum information architectures.Comment: 5 pages, 4 figure
Coherence freeze in an optical lattice investigated via pump-probe spectroscopy
Motivated by our observation of fast echo decay and a surprising coherence
freeze, we have developed a pump-probe spectroscopy technique for vibrational
states of ultracold Rb atoms in an optical lattice to gain information
about the memory dynamics of the system. We use pump-probe spectroscopy to
monitor the time-dependent changes of frequencies experienced by atoms and to
characterize the probability distribution of these frequency trajectories. We
show that the inferred distribution, unlike a naive microscopic model of the
lattice, correctly predicts the main features of the observed echo decay.Comment: 4 pages, 5 figure
Constraining scalar fields with stellar kinematics and collisional dark matter
The existence and detection of scalar fields could provide solutions to
long-standing puzzles about the nature of dark matter, the dark compact objects
at the centre of most galaxies, and other phenomena. Yet, self-interacting
scalar fields are very poorly constrained by astronomical observations, leading
to great uncertainties in estimates of the mass and the
self-interacting coupling constant of these fields. To counter this,
we have systematically employed available astronomical observations to develop
new constraints, considerably restricting this parameter space. In particular,
by exploiting precise observations of stellar dynamics at the centre of our
Galaxy and assuming that these dynamics can be explained by a single boson
star, we determine an upper limit for the boson star compactness and impose
significant limits on the values of the properties of possible scalar fields.
Requiring the scalar field particle to follow a collisional dark matter model
further narrows these constraints. Most importantly, we find that if a scalar
dark matter particle does exist, then it cannot account for both the
dark-matter halos and the existence of dark compact objects in galactic nucleiComment: 23 pages, 8 figures; accepted for publication by JCAP after minor
change
A preliminary assessment of the potential health and genetic impacts of releasing confiscated passerines into the wild: A reduced-risk approach
The illegal capture and trade of wild birds have long been threats to biodiversity. The rehabilitation and release of confiscated animals may be a useful conservation tool in species management. However, differences between populations regarding health (e.g., different pathogens) and adaptation (e.g., local adaptation) must be taken into account, since both can negatively impact the recipient population. In this pilot study, we used two of the most illegally trafficked Brazilian wild passerine species, namely the red-crested cardinal (Paroaria coronata) and green-winged saltator (Saltator similis) as case studies and assessed some of the health threats that the release of confiscated passerines may pose to free-living birds. We also investigated the level of difference in mitochondrial genetic structure among populations living in different ecoregions. Blood, feces, and oropharyngeal swabs from confiscated (n = 115) and free-living (n = 120) passerines from the release sites were tested for the Newcastle disease virus, Salmonella spp., and Mycoplasma gallisepticum. These are considered major avian diseases by the Brazilian National Avian Health Program. We analyzed mtDNA to study the difference in genetic structure between populations using samples from 127 free-living passerines. We found no evidence of the Newcastle disease virus or Salmonella spp. in confiscated or free-living passerines from either species. However, the levels of infection with M. galissepticum detected in our study for red-crested cardinals and green-winged saltators calls for a high degree of caution in captive release programs. The difference in genetic structure between populations occurring in different regions was low, and was not significant between those from the Pampa/Subtropical Grasslands region. These results suggest that it may be possible to establish a cost-effective and sensitive protocol for releasing confiscated songbirds, provided that further genome-wide studies indicate that the functional genetic diversity among (at least some of the) populations is also low.Fil: Cruz, Cláudio E. F.. Universidade Federal do Rio Grande do Sul; BrasilFil: Funkler, Gustavo R.. Universidade Federal do Rio Grande do Sul; Brasil. LaboratĂłrio Porto Belo; BrasilFil: Zani, AndrĂ© L. S.. Universidade Federal do Rio Grande do Sul; BrasilFil: Wagner, Paulo G. C.. Centro de Triagem de Animais Silvestres; BrasilFil: Andretta, Ines. Universidade Federal do Rio Grande do Sul; BrasilFil: Segura, Luciano Noel. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. DivisiĂłn ZoologĂa de Vertebrados; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata; ArgentinaFil: Fagundes, Nelson J. R.. Universidade Federal do Rio Grande do Sul; Brasi
Crack-cocaine users have less family cohesion than alcohol users
Objective: Many studies correlate characteristics of family functioning and the development of drug addiction. This study sought to evaluate and compare the family environment styles of two groups of psychoactive substance users: 1) alcohol-only users and 2) crack-cocaine users. Methods: Three hundred and sixty-four users of alcohol, crack-cocaine, and other drugs, recruited from research centers in four Brazilian capitals participated in this study. Subjects were evaluated through the Family Environment Scale and the Addiction Severity Index, 6th version (ASI-6). ASI-6 t-scores were compared by analysis of variance (ANOVA) and post-hoc tests. A final model was obtained using a logistic regression analysis. All analyses were adjusted for partner, age, and psychiatric t-score. Results: We found a significant difference between groups in the cohesion subscale (p = 0.044). The post-hoc test revealed a difference of 1.06 points (95% CI 0.11-2.01) between groups 1 (6.45 +/- 0.28) and 2 (5.38 +/- 0.20). No significant between-group differences were observed in the other subscales. However, categorical analyses of variables regarding family dynamic showed that crack users more often reported that sometimes people in their family hit each other (30.4% vs. 13.2%, p = 0.007) and that people in their family frequently compared each other regarding work and/or school achievement (57.2% vs. 42.6%, p = 0.041). Conclusion: These results suggest that families of crack-cocaine users are less cohesive than families of alcohol users. This type of family environment may affect treatment outcome, and should thus be adequately approached.SENADNational Institutes of Health/National Institute on Drug AbuseUniv Fed Rio do Grande UFRGS, HCPA, CPAD, Porto Alegre, RS, BrazilHCPA, Unidade Bioestat, Porto Alegre, RS, BrazilUniv Fed Rio Grande do Sul, Lab Biossinais Fenomenol & Cognicao, Inst Psicol, Porto Alegre, RS, BrazilUniv Fed Sao Paulo UNIFESP, Dept Psicobiol, Sao Paulo, SP, BrazilUniv Fed Rio de Janeiro UFRJ, Inst Psiquiatria, Rio De Janeiro, RJ, BrazilUniv Fed Sao Paulo UNIFESP, Dept Psicobiol, Sao Paulo, SP, BrazilSENAD: TC 005/2005Web of Scienc
The repertoire of somatic genetic alterations of acinic cell carcinomas of the breast: an exploratory, hypothesis-generating study
Neotropical Freshwater Fishes: A dataset of occurrence and abundance of freshwater fishes in the Neotropics
The Neotropical region hosts 4225 freshwater fish species, ranking first among the world's most diverse regions for freshwater fishes. Our NEOTROPICAL FRESHWATER FISHES data set is the first to produce a large-scale Neotropical freshwater fish inventory, covering the entire Neotropical region from Mexico and the Caribbean in the north to the southern limits in Argentina, Paraguay, Chile, and Uruguay. We compiled 185,787 distribution records, with unique georeferenced coordinates, for the 4225 species, represented by occurrence and abundance data. The number of species for the most numerous orders are as follows: Characiformes (1289), Siluriformes (1384), Cichliformes (354), Cyprinodontiformes (245), and Gymnotiformes (135). The most recorded species was the characid Astyanax fasciatus (4696 records). We registered 116,802 distribution records for native species, compared to 1802 distribution records for nonnative species. The main aim of the NEOTROPICAL FRESHWATER FISHES data set was to make these occurrence and abundance data accessible for international researchers to develop ecological and macroecological studies, from local to regional scales, with focal fish species, families, or orders. We anticipate that the NEOTROPICAL FRESHWATER FISHES data set will be valuable for studies on a wide range of ecological processes, such as trophic cascades, fishery pressure, the effects of habitat loss and fragmentation, and the impacts of species invasion and climate change. There are no copyright restrictions on the data, and please cite this data paper when using the data in publications.Fil: Tonella, LĂvia Helena. Universidade Estadual de Maringá. Departamento de Engenharia QuĂmica. Laboratorio de Pesquisa.; BrasilFil: Ruaro, Renata. Universidade Estadual de Maringá. Departamento de Engenharia QuĂmica. Laboratorio de Pesquisa.; BrasilFil: Daga, Vanessa Salete. Universidade Federal do Paraná; BrasilFil: Garcia, Diego Azevedo Zoccal. Universidade Estadual de Londrina; BrasilFil: Barroso Vitorino JĂşnior, Oscar. Instituto Natureza do Tocantins-Naturatins; BrasilFil: Lobato de MagalhĂŁes, Tatiana. Universidad Autonoma de Queretaro.; MĂ©xicoFil: Reis, Roberto Esser. Museu de CiĂŞncias e Tecnologia; BrasilFil: Di Dario, Fabio. Universidade Federal do Rio de Janeiro; BrasilFil: Petry, Ana Cristina. Universidade Federal do Rio de Janeiro; BrasilFil: Mincarone, Michael Maia. Universidade Federal do Rio de Janeiro; BrasilFil: Assis Montag, Luciano Fogaça. Universidade Federal do Pará; BrasilFil: Pompeu, Paulo Santos. Universidade Federal de Lavras; BrasilFil: Teixeira, Adonias Aphoena Martins. Universidade Estadual da Paraiba; BrasilFil: Carmassi, Alberto Luciano. Universidade Federal de Sao Paulo; Brasil. Universidade Federal do SĂŁo Carlos; BrasilFil: Sánchez, Alberto J.. Universidad Juárez AutĂłnoma de Tabasco; MĂ©xicoFil: Giraldo PĂ©rez, Alejandro. Universidade Federal de Minas Gerais; BrasilFil: Bono, Alessandra. Universidad de Vale do Rio dos Sinos; BrasilFil: Datovo, AlĂ©ssio. Universidade de Sao Paulo; BrasilFil: Flecker, Alexander S.. Cornell University; Estados UnidosFil: Sanches, Alexandra. Universidade de Sao Paulo; Brasil. Universidade Federal do SĂŁo Carlos; BrasilFil: Godinho, Alexandre Lima. Universidade Federal de Minas Gerais; BrasilFil: Matthiensen, Alexandre. Embrapa SuĂnos e Aves; BrasilFil: Peressin, Alexandre. Universidade Federal de Lavras; BrasilFil: Silva Hilsdorf, Alexandre Wagner. Universidade de Mogi das Cruzes; BrasilFil: Barufatti, AlexĂ©ia. Universidade Federal da Grande Dourados; BrasilFil: Hirschmann, Alice. Universidade Federal do Pampa; BrasilFil: Jung, Aline. Universidade Do Estado de Mato Grosso (unemat);Fil: Cruz RamĂrez, Allan K.. Universidad Juárez AutĂłnoma de Tabasco; MĂ©xicoFil: Braga Silva, Alline. Instituto Federal de Goiás; BrasilFil: Cunico, Almir Manoel. Universidade Federal do Paraná; BrasilFil: Tagliaferro, Marina Beatriz. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro Austral de Investigaciones CientĂficas; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto de Diversidad y EcologĂa Animal. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas FĂsicas y Naturales. Instituto de Diversidad y EcologĂa Animal; Argentin
An Epithelial Serine Protease, AgESP, Is Required for Plasmodium Invasion in the Mosquito Anopheles gambiae
Background: Plasmodium parasites need to cross the midgut and salivary gland epithelia to complete their life cycle in the mosquito. However, our understanding of the molecular mechanism and the mosquito genes that participate in this process is still very limited. Methodology/Principal Findings: We identified an Anopheles gambiae epithelial serine protease (AgESP) that is constitutively expressed in the submicrovillar region of mosquito midgut epithelial cells and in the basal side of the salivary glands that is critical for Plasmodium parasites to cross these two epithelial barriers. AgESP silencing greatly reduces Plasmodium berghei and Plasmodium falciparum midgut invasion and prevents the transcriptional activation of gelsolin, a key regulator of actin remodeling and a reported Plasmodium agonist. AgESP expression is highly induced in midgut cells invaded by Plasmodium, suggesting that this protease also participates in the apoptotic response to invasion. In salivary gland epithelial cells, AgESP is localized on the basal side–the surface with which sporozoites interact. AgESP expression in the salivary gland is also induced in response to P. berghei and P. falciparum sporozoite invasion, and AgESP silencing significantly reduces the number of sporozoites that invade this organ. Conclusion: Our findings indicate that AgESP is required for Plasmodium parasites to effectively traverse the midgut and salivary gland epithelial barriers. Plasmodium parasites need to modify the actin cytoskeleton of mosquito epithelial cells t
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