Metastasis and circulating tumor cells

Cancer is a prominent cause of death worldwide. In most cases, it is not the primary tumor which causes death, but the metastases. Metastatic tumors are spread over the entire human body and are more difficult to remove or treat than the primary tumor. In a patient with metastatic disease, circulating tumor cells (CTCs) can be found in venous blood. These circulating tumor cells are part of the metastatic cascade. Clinical studies have shown that these cells can be used to predict treatment response and their presence is strongly associated with poor survival prospects. Enumeration and characterization of CTCs is important as this can help clinicians make more informed decisions when choosing or evaluating treatment. CTC counts are being included in an increasing number of studies and thus are becoming a bigger part of disease diagnosis and therapy management. We present an overview of the most prominent CTC enumeration and characterization methods and discuss the assumptions made \ud about the CTC phenotype. Extensive CTC characterization of for example the DNA, RNA and antigen expression may lead to more understanding of the metastatic process

Turn the tide: scientific research towards an integrated plan for the Upper-Seascheldt

During the last 150 years the Scheldt estuary has seen many changes either to claim land for urban or agricultural development or to improve the navigability. From the 1950’s onwards the most important changes to the character of the estuary could be attributed to infrastructural works such as dike construction and deepening. Even though cause–effect relationships are difficult to determine it is largely accepted that, besides reclamations, the main contribution to the loss of habitat can be attributed to the increase in tidal amplitude. In various studies the relationship between tidal amplification and large scale engineering works, including deepening, (downstream) sand extraction, embankments and straightening works, has been pointed out. It is clear that anthropogenic changes to the system can have serious consequences to the state of the estuary and that future works need to be prepared in a conscious and sustainable manner in order to avoid further tidal amplification.Within the framework of the project “Integrated Plan Upper-Seascheldt” commissioned by the Seascheldt division of the Waterwegen & Zeekanaal NV, it is investigated how navigability can be improved (to class Va) without negative effects to nature and safety against flooding. It is the goal of this integrated study to look for synergy in order to mitigate negative impacts of the proposed measures or even to improve the functioning of the system. In the last 10 years already various environmental measures like de-poldering are being implemented under the SIGMA-Plan.This paper will discuss the evolution of the Seascheldt in relation to historical anthropogenic changes. It will focus on the observed changes in water level, bathymetry, habitats (salt marshes) and sediment concentrations. In addition, the paper will outline the project plan to investigate whether de-poldering projects and other solutions or strategies can be identified that may ‘turn the tide’. This study involves applied scientific research to improve knowledge on (ecological) functioning of the Scheldt Estuary by means of a chain of model developments by the project partners (INBO, UA and FHR)

Official Record of Death of Johanna Maria Wilhelmina Menzel

The death of Johanna Maria Wilhelmina Menzel, widow of Benjamin de Moen and mother of Christina de Moen [Van Raalte] occurred on this date according to the records of the town of Leyden, South Holland, the Netherlands.https://digitalcommons.hope.edu/vrp_1830s/1008/thumbnail.jp

Optimization by Quantum Annealing: Lessons from hard 3-SAT cases

The Path Integral Monte Carlo simulated Quantum Annealing algorithm is applied to the optimization of a large hard instance of the Random 3-SAT Problem (N=10000). The dynamical behavior of the quantum and the classical annealing are compared, showing important qualitative differences in the way of exploring the complex energy landscape of the combinatorial optimization problem. At variance with the results obtained for the Ising spin glass and for the Traveling Salesman Problem, in the present case the linear-schedule Quantum Annealing performance is definitely worse than Classical Annealing. Nevertheless, a quantum cooling protocol based on field-cycling and able to outperform standard classical simulated annealing over short time scales is introduced.Comment: 10 pages, 6 figures, submitted to PR

Using Weak Lensing Dilution to Improve Measurements of the Luminous and Dark Matter in A1689

The E/SO sequence of a cluster defines a boundary redward of which a reliable weak lensing signal can be obtained from background galaxies, uncontaminated by cluster members. For bluer colors, both background and cluster members are present, reducing the distortion signal by the proportion of unlensed cluster members. In deep Subaru and HST/ACS images of A1689 the tangential distortion of galaxies with bluer colors falls rapidly toward the cluster center relative to the lensing signal of the red background. We use this dilution effect to derive the cluster light profile and luminosity function to large radius, with the advantage that no subtraction of far-field background counts is required. The light profile declines smoothly to the limit of the data, r<2Mpc/h, with a constant slope, dlog(L)/dlog(r)=-1.12+-0.06, unlike the lensing mass profile which steepens continuously with radius, so that M/L peaks at an intermediate radius, ~100kpc/h. A flatter behavior is found for the more physically meaningful ratio of dark-matter to stellar-matter, when accounting for the color-mass relation of cluster members. The cluster luminosity function has a flat slope, alpha=-1.05+-0.07, independent of radius and with no faint upturn to M_i'<-12. We establish that the very bluest objects are negligibly contaminated by the cluster V-i'<0.2, because their distortion profile rises towards the center following the red background, but offset higher by ~20%. This larger amplitude is consistent with the greater estimated depth of the faint blue galaxies, z~=2.0 compared to z~=0.85 for the red background, a purely geometric effect related to cosmological parameters. Finally, we improve upon our earlier mass profile by combining both the red and blue background populations, clearly excluding low concentration CDM profiles.Comment: 17 pages, 21 figures, revised version in response to referee comments,(added some discussion, references), conclusions unchanged. Accepted for publication in Ap

Designing Conducting Polymers Using Bioinspired Ant Algorithms

Ant algorithms are inspired in real ants and the main idea is to create virtual ants that travel into the space of possible solution depositing virtual pheromone proportional to how good a specific solution is. This creates a autocatalytic (positive feedback) process that can be used to generate automatic solutions to very difficult problems. In the present work we show that these algorithms can be used coupled to tight-binding hamiltonians to design conducting polymers with pre-specified properties. The methodology is completely general and can be used for a large number of optimization problems in materials science

Resonance Superfluidity: Renormalization of Resonance Scattering Theory

We derive a theory of superfluidity for a dilute Fermi gas that is valid when scattering resonances are present. The treatment of a resonance in many-body atomic physics requires a novel mean-field approach starting from an unconventional microscopic Hamiltonian. The mean-field equations incorporate the microscopic scattering physics, and the solutions to these equations reproduce the energy-dependent scattering properties. This theory describes the high-$T_c$ behavior of the system, and predicts a value of $T_c$ which is a significant fraction of the Fermi temperature. It is shown that this novel mean-field approach does not break down for typical experimental circumstances, even at detunings close to resonance. As an example of the application of our theory we investigate the feasibility for achieving superfluidity in an ultracold gas of fermionic $^6$Li.Comment: 15 pages, 10 figure

Sediment transport modelling (TELEMAC-3D + GAIA) case study: sand disposals in the Western Scheldt

Hydrodynamic

Forming a constant density medium close to long gamma-ray bursts

The progenitor stars of long Gamma-Ray Bursts (GRBs) are thought to be Wolf-Rayet stars, which generate a massive and energetic wind. Nevertheless, about 25 percent of all GRB afterglows light curves indicate a constant density medium close to the exploding star. We explore various ways to produce this, by creating situations where the wind termination shock arrives very close to the star, as the shocked wind material has a nearly constant density. Typically, the distance between a Wolf-Rayet star and the wind termination shock is too large to allow afterglow formation in the shocked wind material. Here, we investigate possible causes allowing for a smaller distance: A high density or a high pressure in the surrounding interstellar medium (ISM), a weak Wolf-Rayet star wind, the presence of a binary companion, and fast motion of the Wolf-Rayet star relative to the ISM. We find that all four scenarios are possible in a limited parameter space, but that none of them is by itself likely to explain the large fraction of constant density afterglows. A low GRB progenitor metallicity, and a high GRB energy make the occurrence of a GRB afterglow in a constant density medium more likely. This may be consistent with constant densities beingpreferentially found for energetic, high redshift GRBs.Comment: 13 pages, 13 figures, new version: as accepted by Astronomy & Astrophysic