58 research outputs found
Two bosonic quantum walkers in one-dimensional optical lattices
Dynamical properties of two bosonic quantum walkers in a one-dimensional
lattice are studied theoretically. Depending on the initial state,
interactions, lattice tilting, and lattice disorder, whole plethora of
different behaviors are observed. Particularly, it is shown that two bosons
system manifests the many-body localization like behavior in the presence of a
quenched disorder. The whole analysis is based on a specific decomposition of
the temporal density profile into different contributions from singly and
doubly occupied sites. In this way, the role of interactions is extracted.
Since the contributions can be directly measured in experiments with ultra-cold
atoms in optical lattices, the predictions presented may have some importance
for upcoming experiment.Comment: upgraded reference
Szkolenie ratowników medycznych dla potrzeb konfliktów zbrojnych
Praca nierecenzowanaPraca dotyczy problemu szkolenia żołnierzy i ratowników medycznych dla potrzeb kon-fliktów zbrojnych. W rozdziale I zostały omówione podstawowe pojęcia i kwestie związane z ratownictwem taktycznym, historią jego powstania oraz badaniami, które przyczyniły się do jego rozwoju. W rozdziale II opisano szkolenia i kursy w których uczestniczą żołnierze i personel medyczny Armii Stanów Zjednoczonych. Scharakteryzowano w nim rodzaje szkoleń w odniesieniu do zakresu czynności medycznych wykonywanych w różnych strefach działania. W rozdziale III opisano zwięźle zagadnienie szkolenia medycznego w Siłach Zbrojnych RP. Ukazuje on problematykę szkolenia oraz kursy w których uczestniczą polscy żołnierze i personel medyczny. Podsumowanie zawiera kluczowe wnioski oraz własne przemyślenia.The essay describes soldiers and medical lifeguards training for war conflicts. The first chapter writes up the definition of tactical rescue, history and performed examinations which contributed to its progress. The second chapter describes trainings and courses for soldiers and medical staff of the US Army. Also briefly describes medical activities which should be made in correct zones of action. The TACEVAC definition is explained too in this chapter. The third chapter details the issue of medical training in Polish Armed Forces. Writes up about the problems in enforcing law regulations, which affects medical activities. Shortly describes trainings and courses for polish soldiers and medical staff. In the resume there are my personal crucial conclusions and suggestions
Assessment of hydrocephalus in children based on digital image processing and analysis
Hydrocephalus is a pathological condition of the central nervous system which often affects neonates and young children. It manifests itself as an abnormal accumulation of cerebrospinal fluid within the ventricular system of the brain with its subsequent progression. One of the most important diagnostic methods of identifying hydrocephalus is Computer Tomography (CT). The enlarged ventricular system is clearly visible on CT scans. However, the assessment of the disease progress usually relies on the radiologist’s judgment and manual measurements, which are subjective, cumbersome and have limited accuracy. Therefore, this paper regards the problem of semi-automatic assessment of hydrocephalus using image processing and analysis algorithms. In particular, automated determination of popular indices of the disease progress is considered. Algorithms for the detection, semi-automatic segmentation and numerical description of the lesion are proposed. Specifically, the disease progress is determined using shape analysis algorithms. Numerical results provided by the introduced methods are presented and compared with those calculated manually by a radiologist and a trained operator. The comparison proves the correctness of the introduced approach
Tracking locality in time evolution of disordered systems
Using local density correlation functions for a one-dimensional spin system,
we introduce a correlation function difference (CFD) which compares
correlations on a given site between a full system of size and its
restriction to sites. We show that CFD provides useful information on
transfer of information in quantum many-body systems by considering the
examples of ergodic, Anderson, and many-body localized regimes in disordered
XXZ spin chain. In the ergodic phase, we find that the propagation of CFD is
asymptotically faster than the spin transport but slower than the ballistic
propagation implied by the Lieb-Robinson bound. In contrast, in the localized
cases, we unravel an exponentially slow relaxation of CFD. Connections between
CFD and other observables detecting non-local correlations in the system are
discussed.Comment: 12 pages, 11 figures. Comments welcome
Unsupervised detection of decoupled subspaces: many-body scars and beyond
Highly excited eigenstates of quantum many-body systems are typically
featureless thermal states. Some systems, however, possess a small number of
special, low-entanglement eigenstates known as quantum scars. We introduce a
quantum-inspired machine learning platform based on a Quantum Variational
Autoencoder (QVAE) that detects families of scar states in spectra of many-body
systems. Unlike a classical autoencoder, QVAE performs a parametrized unitary
operation, allowing us to compress a single eigenstate into a smaller number of
qubits. We demonstrate that the autoencoder trained on a scar state is able to
detect the whole family of scar states sharing common features with the input
state. We identify families of quantum many-body scars in the PXP model beyond
the and families and find dynamically decoupled
subspaces in the Hilbert space of disordered, interacting spin ladder model.
The possibility of an automatic detection of subspaces of scar states opens new
pathways in studies of models with a weak breakdown of ergodicity and
fragmented Hilbert spaces.Comment: Author accepted manuscript to be published in PR
Tunneling-Induced Restoration of the Degeneracy and the Time-Reversal Symmetry Breaking in Optical Lattices
We study the ground-state properties of bosons loaded into the -band of a
one dimensional optical lattice. We show that the phase diagram of the system
is substantially affected by the anharmonicity of the lattice potential. In
particular, for a certain range of tunneling strength, the full many-body
ground state of the system becomes degenerate. In this region, an additional
symmetry of the system, namely the parity of the occupation number of the
chosen orbital, is spontaneously broken. The state with nonvanishing staggered
angular momentum, which breaks the time-reversal symmetry, becomes the true
ground state of the system.Comment: 5 pages, 2 figure
The cardio-vascular safety of tyrosine kinase inhibitors
Przedstawiono aktualne dane dotyczące powikłań sercowo-naczyniowych u pacjentów z przewlekłą białaczką szpikową leczonych trzema najczęściej stosowanymi inhibitorami kinazy tyrozynowej, tj.: imatynibem, nilotynibem lub dazatynibem. Ponadto zaproponowano model monitorowania kardiologicznego w tej grupie chorych.A literature review is presented that focuses on cardiovascular complications on those patients suffering from chronic myelogenous leukemia that were treated with the 3 most commonly used tyrosine kinase inhibitors; imatinib, nilotinib or dasatinib. An appropriate scheme for their cardiac monitoring is also proposed
Non-standard Hubbard models in optical lattices: a review
Originally, the Hubbard model has been derived for describing the behaviour
of strongly-correlated electrons in solids. However, since over a decade now,
variations of it are also routinely being implemented with ultracold atoms in
optical lattices. We review some of the rich literature on this subject, with a
focus on more recent non-standard forms of the Hubbard model. After an
introduction to standard (fermionic and bosonic) Hubbard models, we discuss
briefly common models for mixtures, as well as the so called extended
Bose-Hubbard models, that include interactions between neighboring sites,
next-neighboring sites, and so on. The main part of the review discusses the
importance of additional terms appearing when refining the tight-binding
approximation on the original physical Hamiltonian. Even when restricting the
models to the lowest Bloch band is justified, the standard approach neglects
the density-induced tunneling (which has the same origin as the usual on-site
interaction). The importance of these contributions is discussed for both
contact and dipolar interactions. For sufficiently strong interactions, also
the effects related to higher Bloch bands become important even for deep
optical lattices. Different approaches that aim at incorporating these effects,
mainly via dressing the basis Wannier functions with interactions, leading to
effective, density-dependent Hubbard-type models, are reviewed. We discuss also
examples of Hubbard-like models that explicitly involve higher -orbitals, as
well as models that couple dynamically spin and orbital degrees of freedom.
Finally, we review mean-field nonlinear-Schr\"odinger models of the Salerno
type that share with the non-standard Hubbard models the nonlinear coupling
between the adjacent sites. In that part, discrete solitons are the main
subject of the consideration. We conclude by listing some future open problems.Comment: expanded version 47pp, accepted in Rep. Prog. Phy
Period changes of the sample of eclipsing binaries with active chromospheres
In this work we present results derived from analysis of the O-C behaviour of ten eclipsing binary systems: AR Lac, CG Cyg, HP Aur, MM Her, RS CVn, RT And, SV Cam, V471 Tau, WW Dra and CF Tuc. It was proved on the basis of moments of minima compiled from the literature and new ones determined from recent observations, that these binaries show long term (19-91 years) modulations of their orbital periods, clearly visible in their O-C diagrams. Two possible explanations for this effect are considered: (1) the light-travel time effect due to the presence of a third body orbiting the eclipsing systems; (2) the Applegate mechanism predicting period modulation by changes in the distribution of angular momentum as a star goes through its activity cycles. It was found that in the case of four systems the existence of a third star, orbiting the binary, is a more plausible explanation of observations
The development of new methodology for determination of vincristine (VCR) in human serum using LC-MS/MS-based method for medical diagnostics
In this article, we have presented the development and validation of a rapid and sensitive reversed-phase liquid chromatography with tandem mass spectrometry (LC-MS/MS) method for the determination of vincristine (VCR) in patient serum samples. Chromatographic separation was achieved on a Kinetex(®) (Singapore) column using a mobile phase consisting of 25 mM acetic acid and 0.3% formic acid (A) and methanol (B) in a gradient elution mode at a flow rate of 0.3 mL/min. The VCR and internal standard (vinblastine) were monitored using the multiple reaction monitoring mode under positive electrospray ionization. The lower limit of quantification (LLOQ) was 0.67 ng/mL, and the upper limit of quantification (ULOQ) was 250 ng/mL for VCR. The calculated values of LOD and LOQ for VCR were 0.075 and 0.228 ng/mL, respectively. The calibration curve was linear over the VCR concentration range of 1.0–250 ng/mL in serum. The intra- and inter-day precision and precision were within the generally accepted criteria for the bioanalytical method (<15%). The method was successfully applied to the analysis of serum samples in clinical practice
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