2,613 research outputs found
Similarity and dissimilarity in intergroup relations: different dimensions, different processes
Photoassociation dynamics in a Bose-Einstein condensate
A dynamical many body theory of single color photoassociation in a
Bose-Einstein condensate is presented. The theory describes the time evolution
of a condensed atomic ensemble under the influence of an arbitrarily varying
near resonant laser pulse, which strongly modifies the binary scattering
properties. In particular, when considering situations with rapid variations
and high light intensities the approach described in this article leads, in a
consistent way, beyond standard mean field techniques. This allows to address
the question of limits to the photoassociation rate due to many body effects
which has caused extensive discussions in the recent past. Both, the possible
loss rate of condensate atoms and the amount of stable ground state molecules
achievable within a certain time are found to be stronger limited than
according to mean field theory. By systematically treating the dynamics of the
connected Green's function for pair correlations the resonantly driven
population of the excited molecular state as well as scattering into the
continuum of non-condensed atomic states are taken into account. A detailed
analysis of the low energy stationary scattering properties of two atoms
modified by the near resonant photoassociation laser, in particular of the
dressed state spectrum of the relative motion prepares for the analysis of the
many body dynamics. The consequences of the finite lifetime of the resonantly
coupled bound state are discussed in the two body as well as in the many body
context. Extending the two body description to scattering in a tight trap
reveals the modifications to the near resonant adiabatic dressed levels caused
by the decay of the excited molecular state.Comment: 27 pages revtex, 16 figure
Fitness of antibiotic-resistant bacteria in the environment: a laboratory activity
In this laboratory experiment, we propose an opportunity for students to broaden their understanding of the ecology of antibiotic-resistant and sensitive waterborne bacteria. Antibiotics can be found in rivers or soil as a consequence of agricultural practices or as a result of human use. Concentrations of antibiotics in the environment may range from a few ng to μg L-1. Such concentrations can affect the selection and fitness of resistant bacteria. In this laboratory activity, students learn how to set up a fitness experiment by using an isogenic pair of antibiotic-resistant and sensitive bacteria in the presence or absence of selective pressure. Microcosms were generated by using filtered river water containing populations of resistant and sensitive bacteria. Competition of both populations was measured in the presence or absence of antibiotics. Students appreciated the use of microcosms for in vitro experiments and the extent to which the fitness of resistant and sensitive bacteria changed in the presence and/or absence of a selective pressure in river water. Student learning was measured by using different types of assessments: multiple-choice, true/false, fill in the blanks, laboratory skills observations, and laboratory reports. After the laboratory activity, the percentage of correct answers significantly rose from ~20% to ~85%. Laboratory skills were also evaluated during the exercises, showing no major issues during the experiment. Students showed proficiency in analyzing the complexity of fitness data by reaching a mean of 5.57 (standard error 0.57) over a maximum score of 7 points
Plasmid profile, antibiotic resistance, and phenotypic virulent strains of S. flexneri
Shigellosis is an acute gastroenteritis caused by Shigella species. The purpose of this study was to determine plasmid profile, antibiotic resistance and phenotypic virulent by Congo red between S. flexneri strains. The isolated bacteria were identified by standard bacterial and biochemical methods. Plasmids were isolated by alkaline lysis method. Antibiotic susceptibility test was performed according to "kirby-Bauer" method. Serological reactions were carried by slide agglutination tests with both polyclonal and monoclonal antiserum kits. Virulent strains were isolated on a TSA plate contained Congo red dye concentration. From 350 isolated Shigella species, 142 (40.57) were S. flexneri. Eleven distinct plasmid profile patterns were identified. Of S. flexneri isolates, 95 were resistant to tetracycline, 85.6 to SXT and 75.3 to ampicillin. All the isolates were sensitive to ciprofloxacin. Our results showed that 39 were serotype II. 45.56 of S. flexneri were Congo red positive. Antibiotic resistant determination in each case may prevent drug resistance increase. Since Congo red binding test is cheap and simple it can be used to determine virulence properties of S. flexneri
Evaluation of risk factors for intrapartum caesarean section in low risk multiparous women with prior vaginal deliveries
Background: In 2015, WHO proposed the use of the Robson classification as a global standard for assessing, monitoring and comparing caesarean section rates both within and between healthcare facilities. Robson’s group 3 and 4 consist of multiparous women with term singleton pregnancies who have previously delivered vaginally and attempts to audit the caesarean sections in these 2 groups may be helpful to reduce primary caesarean sections in multiparous women.
Methods: The eligible subjects (belonging to Robson group 3 and 4) were recruited from the labor room of the Obstetrics and Gynecology department of SSG hospital, Baroda. Those who delivered by caesarean section during the study period were enrolled in the study as cases. Those who delivered vaginally immediately following the case formed the controls. Relevant demographic characteristics, parity, interval time between prior birth, history of macrosomic birth, cervical dilatation at the admission to the hospital, obstetric and neonatal outcomes were obtained and analyzed..
Results: On performing multivariate regression, age, birth weight of previous child, time since last delivery, cervical dilatation were found to be significant independent risk factors for LSCS after adjusting for confounding factors. The most common indication for caesarean section was fetal distress with meconium stained liquor.
Conclusions: In low risk multiparous women with previous vaginal delivery, Maternal age, birth weight of previous child, time since last delivery and cervical dilatation were significant independent risk factors of LSCS. Gestational age, parity, BMI and labor induction were not found to increase the risk of caesarean delivery
Thymic Squamous Cell Carcinoma? Do you confirm this diagnosis?
Introduction
In dogs thymic carcinoma is considered rare and distinguishes itself from thymoma by its cytologically malignant features, extensive local invasion, and a substantial potential for metastasis. Surgical excision is the treatment of choice for most thymic tumours, with the exception of lymphoma.
Medical History
A 9 years old cross-breed male dog was presented due to cough and respiratory distress with duration of 4 weeks. The animal presented with inspiratory dyspnea and cyanosis. A mass, dorsal to the pharynx, was diagnosed after clinical and radiographical examination, suspected of thyroid neoplasia. Cytology was performed and revealed cells consistent with malignancy, apparently carcinoma with high parameters of aggressiveness. As a form of treatment and to obtain a definitive diagnosis, was decided to surgical removed the mass which measured 7.8x3.7x3.5cm.
Material and Methods
The sample was fixed in 10 % buffered formalin solution for histological evaluation and sent to the Anatomic Pathology Laboratory of the Agrarian Superior School of Viseu, in Portugal, for histological evaluation.
Results
Microscopic examination revealed that we were in presence of a lymphoid organ, with peculiar features, namely a small to intermediate-sized lymphoid cells, "starry-sky" pattern and rounded eosinophilic perivascular arrangements resembling Hassall's corpuscles. Concomitantly, typical features of squamous cell carcinoma were evident.
Discussion and Conclusion
In conclusion, based on its histological features, the authors suggested the diagnosis of Thymic Squamous Cell Carcinoma with an unusual location. Thymic tumours in dogs are predominantly located in the anterior mediastinum but they may extend from the neck to the posterior mediastinum.This work was supported by Portuguese Foundation for Science and Technology, Center for Studies in Education, Technologies and by Health and by strategic project PEst-OE/CED/UI4016/201
Nonlocality as a Benchmark for Universal Quantum Computation in Ising Anyon Topological Quantum Computers
An obstacle affecting any proposal for a topological quantum computer based
on Ising anyons is that quasiparticle braiding can only implement a finite
(non-universal) set of quantum operations. The computational power of this
restricted set of operations (often called stabilizer operations) has been
studied in quantum information theory, and it is known that no
quantum-computational advantage can be obtained without the help of an
additional non-stabilizer operation. Similarly, a bipartite two-qubit system
based on Ising anyons cannot exhibit non-locality (in the sense of violating a
Bell inequality) when only topologically protected stabilizer operations are
performed. To produce correlations that cannot be described by a local hidden
variable model again requires the use of a non-stabilizer operation. Using
geometric techniques, we relate the sets of operations that enable universal
quantum computing (UQC) with those that enable violation of a Bell inequality.
Motivated by the fact that non-stabilizer operations are expected to be highly
imperfect, our aim is to provide a benchmark for identifying UQC-enabling
operations that is both experimentally practical and conceptually simple. We
show that any (noisy) single-qubit non-stabilizer operation that, together with
perfect stabilizer operations, enables violation of the simplest two-qubit Bell
inequality can also be used to enable UQC. This benchmarking requires finding
the expectation values of two distinct Pauli measurements on each qubit of a
bipartite system.Comment: 12 pages, 2 figure
Muscle function is associated with future patient-reported outcomes in young adults with ACL injury
BACKGROUND/AIM: Consequences of an anterior cruciate ligament (ACL) injury include worse patient-reported outcomes (PROs) and a decrease in activity level. Muscle function can be improved by targeted exercise. Our aims were to investigate cross-sectional and longitudinal associations among lower extremity muscle function and PROs after ACL injury.METHODS: Fifty-four participants (15 women, mean 30 years) with ACL injury or reconstruction, from the Knee Anterior Cruciate Ligament, Nonsurgical versus Surgical Treatment (KANON) trial (ISRCTN84752559), were assessed with hop performance, muscle power and postural orientation 3 years (SD 0.85) after ACL injury. PROs at 3 and 5 years after injury included Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales Function in sport and recreation (KOOS Sport/rec) and Knee-related Quality of life (KOOS QoL), KOOS item Q3 (KOOS Q3), Tegner Activity Scale and Activity Rating Scale (ARS). Partial Spearman's rank-order correlation was used to analyse correlations between muscle function and PROs, controlling for gender and treatment.RESULTS: Numerous cross-sectional correlations were observed between muscle function and PROs (rsp≈0.3-0.5, p≤0.045). Worse hop performance and worse postural orientation were associated with worse KOOS scores 2 years later (rsp≥0.280, p≤0.045). Worse muscle power was associated with lower future ARS scores (rsp=0.281, p=0.044).CONCLUSIONS: The moderate associations suggest that improving muscle function during rehabilitation could improve present and future PROs
Optimizing entangling quantum gates for physical systems
Optimal control theory is a versatile tool that presents a route to
significantly improving figures of merit for quantum information tasks. We
combine it here with the geometric theory for local equivalence classes of
two-qubit operations to derive an optimization algorithm that determines the
best entangling two-qubit gate for a given physical setting. We demonstrate the
power of this approach for trapped polar molecules and neutral atoms.Comment: extended version; Phys. Rev. A (2011
Mapping European social psychology: co-word analysis of the communications at the 10th General Meeting of the EAESP
This study aims to provide a picture of the present European research topics in Social Psychology, using the 339 papers presented at the 1993 General Meeting of the EAESP. The most frequent themes of research are analysed and the structure of the association of those themes are described in a two-factor structure. The first factor differentiates research in terms of level of analysis and the second factor contrasts types of applied research
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