Quantum-field dynamics of expanding and contracting Bose-Einstein condensates

We analyze the dynamics of quantum statistics in a harmonically trapped Bose-Einstein condensate, whose two-body interaction strength is controlled via a Feshbach resonance. From an initially non-interacting coherent state, the quantum field undergoes Kerr squeezing, which can be qualitatively described with a single mode model. To render the effect experimentally accessible, we propose a homodyne scheme, based on two hyperfine components, which converts the quadrature squeezing into number squeezing. The scheme is numerically demonstrated using a two-component Hartree-Fock-Bogoliubov formalism.Comment: 9 pages, 4 figure

A search on Dirac equation

The solutions, in terms of orthogonal polynomials, of Dirac equation with analytically solvable potentials are investigated within a novel formalism by transforming the relativistic equation into a Schrodinger like one. Earlier results are discussed in a unified framework and certain solutions of a large class of potentials are given.Comment: 9 page

EM‐driven tolerance optimization of compact microwave components using response feature surrogates

Improving microwave component immunity to parameter deviations is of high importance, especially in the case of stringent performance specifications. This paper proposes a computationally efficient algorithm for robustness enhancement of compact microwave circuits. The objective is to increase the acceptable levels of geometry parameter deviations under which the prescribed performance specifications are still fulfilled. Our approach incorporates feature-based surrogate models utilized for low-cost prediction of the fabrication yield, as well as the trustregion framework for adaptive control of design relocation and ensuring convergence of the optimization process. The efficacy of our technique is demonstrated using a broadband microstrip filter.ITESO, A.C

Conflict sources and management in ICU setting before and during COVID-19: a scoping review of the literature

Introduction. Conflicts are an inherent part of work within any organisation. They can arise between members of an interdisciplinary team (or between teams representing different departments), between patients and team members/family members, and patients' families and team members. Various conflict situations among employees may occur, therefore it is very important to identify their causes and take preventive or targeted corrective measures. The aim of this study was to review the available literature concerning conflicts arising in ICUs¿their types, methods of expression as well as their management and mitigation. In addition, we reviewed the available literature on the impact of the pandemic on the ICU environment caring for COVID-19 patients. Methods. The databases were searched. Single key words or their combinations using AND or OR operators were entered. Eventually, 15 articles were included in our review, which included two identical papers. Results. Conflicts occurred occasionally or rarely; researchers describing ethical conflicts demonstrated a moderate level of exposure to conflicts. The pandemic created many challenges and ethical dilemmas that are a source of ethical conflict. Conclusions. As conflict by nature remains inevitable, adequate procedures in conflict management should be developed and the leadership of managing personnel should be reinforced, because team members frequently expect guidance from their supervisors. The importance of training in interpersonal communication and crisis situation management in healthcare should therefore be emphasised

Relativistic shape invariant potentials

Dirac equation for a charged spinor in electromagnetic field is written for special cases of spherically symmetric potentials. This facilitates the introduction of relativistic extensions of shape invariant potential classes. We obtain the relativistic spectra and spinor wavefunctions for all potentials in one of these classes. The nonrelativistic limit reproduces the usual Rosen-Morse I & II, Eckart, Poschl-Teller, and Scarf potentials.Comment: Corrigendum: The last statement above equation (1) is now corrected and replaced by two new statement

Assessment of prognostic significance of cytoplasmic survivin expression in advanced oesophageal cancer.

Survivin is a member of the family of proteins, which inhibit apoptosis (inhibitor of apoptosis proteins - IAP). Expression of survivin was found in colorectal cancer, neuroblastoma, bladder cancer, non-small cell lung cancer, and breast cancer. There is some recent data indicating the correlation of poor prognosis and worse response to chemotherapy in patients with oesophageal squamous cell carcinoma (OSCC) expressing survivin. The aim of the present study was to assess survivin expression in cancerous tissue of patients with advanced OSCC and to test the potential correlation between survivin expression and clinicopathological data. Forty two patients (mean age 58.36+/-8.97 yrs), who were oesophagectomised due to squamous cell carcinoma of the thoracic oesophagus between 1998 and 2000, were retrospectively analysed. Cytoplasmic survivin expression, examined immunohistochemically, was found in 35 (83.33%) cases. No statistically significant correlation between survivin expression in the tumour and patients' gender, TNM stage, or vascular involvement was noted. The mean survival of patients with cytoplasmic survivin expression (17.81+/-5.51 months) was not statistically different to those with negative survivin staining (16+/-6.28 months) as assessed by Mantel-Cox test (p=0.49). Univariate regression analysis revealed UICC staging as the only predictor of survival in the analysed group (

Interaction of matter-wave gap solitons in optical lattices

We study mobility and interaction of gap solitons in a Bose-Einstein condensate (BEC) confined by an optical lattice potential. Such localized wavepackets can exist only in the gaps of the matter-wave band-gap spectrum and their interaction properties are shown to serve as a measure of discreteness imposed onto a BEC by the lattice potential. We show that inelastic collisions of two weakly localized near-the-band-edge gap solitons provide simple and effective means for generating strongly localized in-gap solitons through soliton fusion.Comment: 12 pages, 7 figure

Dynamical formation and interaction of bright solitary waves and solitons in the collapse of Bose-Einstein condensates with attractive interactions

We model the dynamics of formation of multiple, long-lived, bright solitary waves in the collapse of Bose-Einstein condensates with attractive interactions as studied in the experiment of Cornish et al. [Phys. Rev. Lett. 96 (2006) 170401]. Using both mean-field and quantum field simulation techniques, we find that while a number of separated wave packets form as observed in the experiment, they do not have a repulsive \pi phase difference that has been previously inferred. We observe that the inclusion of quantum fluctuations causes soliton dynamics to be predominantly repulsive in one dimensional simulations independent of their initial relative phase. However, indicative three-dimensional simulations do not support this conclusion and in fact show that quantum noise has a negative impact on bright solitary wave lifetimes. Finally, we show that condensate oscillations, after the collapse, may serve to deduce three-body recombination rates, and that the remnant atom number may still exceed the critical number for collapse for as long as three seconds independent of the relative phases of the bright solitary waves.Comment: 14 pages, 5 figure

Maternal stress during pregnancy and neurodevelopmental outcomes of children during the first 2 years of life

AIM: A growing body of literature documents associations between maternal stress in pregnancy and child development, but findings across studies are often inconsistent. The aim of this study was to estimate the association between exposure to different kinds of prenatal stress and child psychomotor development. METHODS: The study population consisted of 372 mother-child pairs from Polish Mother and Child Cohort. The analysis was restricted to the women who worked at least 1 month during pregnancy period. Maternal psychological stress during pregnancy was assessed based on: the Subjective Work Characteristics Questionnaire, Perceived Stress Scale and Social Readjustment Rating Scale. The level of satisfaction with family functioning and support was evaluated by APGAR Family Scale. Child psychomotor development was assessed at the 12th and 24th months of age by Bayley Scales of Infant and Toddler Development. RESULTS: Negative impact on child cognitive development at the age of two was observed for the Perceived Stress Scale (β = -0.8; P = 0.01) and the Social Readjustment Rating Scale (β = -0.4; P = 0.03) after adjusting for the variety of confounders. Occupational stress, as well as satisfaction with family functioning, was not significantly associated with child psychomotor development (P > 0.05). CONCLUSIONS: The study supports the findings that prenatal exposure to maternal stress is significantly associated with decreased child cognitive functions. In order to further understand and quantify the effects of prenatal stress on child neurodevelopment further studies are needed. This will be important for developing interventions that provide more assistance to pregnant women, including emotional support or help to manage psychological stress