Microwave Angiography by Ultra-Wideband Sounding: A Preliminary Investigation.

Angiography is a very informative method for physicians such as cardiologists, neurologists and neuroscientists. The current modalities experience some shortages, e.g.

The process of slowing down in clinical reasoning during ultrasound consultations.

Objectives: In clinical reasoning, clinicians need to switch between automatic and effortful reasoning to solve both routine and non-routine problems. This requires the ability to recognise when a problem is non-routine and adapt one's reasoning mode accordingly, that is to 'slow down' the reasoning process. In the current study, we explored the process of these transitions between automatic and effortful reasoning by radiologists who performed ultrasound examinations during consultations at the polyclinic.

XUV-induced reactions in benzene on sub-10 fs timescale: nonadiabatic relaxation and proton migration.

Unraveling ultrafast dynamical processes in highly excited molecular species has an impact on our understanding of chemical processes such as combustion or the chemical composition of molecular clouds in the universe. In this article we use short (<7 fs) XUV pulses to produce excited cationic states of benzene molecules and probe their dynamics using few-cycle VIS/NIR laser pulses. The excited states produced by the XUV pulses lie in an especially complex spectral region where multi-electronic effects play a dominant role.

The identity of oreias Temminck, 1840-solving a taxonomic puzzle.

Vespertilio oreias (generally known as Myotis oreias) has long been considered an endemic bat species to Singapore but its taxonomic status has been in doubt, and no specimens have been found since its description in 1840. Temminck formally described it based on a mounted skin (now in poor condition and accompanied by some skull fragments). The holotype was re-examined and we found it to be a composite, consisting of two separate individuals representing two distinct genera, the skin belonging to a Kerivoula whereas the skull fragments are of a Myotis.

XUV excitation followed by ultrafast non-adiabatic relaxation in PAH molecules as a femto-astrochemistry experiment.

Highly excited molecular species are at play in the chemistry of interstellar media and are involved in the creation of radiation damage in a biological tissue. Recently developed ultrashort extreme ultraviolet light sources offer the high excitation energies and ultrafast time-resolution required for probing the dynamics of highly excited molecular states on femtosecond (fs) (1 fs=10(-15) s) and even attosecond (as) (1 as=10(-18) s) timescales. Here we show that polycyclic aromatic hydrocarbons (PAHs) undergo ultrafast relaxation on a few tens of femtoseconds timescales, involving an interplay between the electronic and vibrational degrees of freedom.

Alignment dependent enhancement of the photoelectron cutoff for multiphoton ionization of molecules.

The multiphoton ionization rate of molecules depends on the alignment of the molecular axis with respect to the ionizing laser polarization. By studying molecular frame photoelectron angular distributions from N(2), O(2), and benzene, we illustrate how the angle-dependent ionization rate affects the photoelectron cutoff energy. We find alignment can enhance the high energy cutoff of the photoelectron spectrum when probing along a nodal plane or when ionization is otherwise suppressed.

Measurement and control of plasma oscillations in femtosecond filaments.

The short-lived longitudinal plasma oscillations generated during filamentation in argon and nitrogen gas are measured with a specially designed current monitor. The magnitude and initial direction of the corresponding currents depend sensitively on laser polarization and nature of the gas. The results are interpreted as resulting from the competition between two forces acting on free electrons born during the filamentation process: the Lorentz laser force and a Coulomb wake force resulting from a lateral expansion of the plasma.

Partitioning of the linear photon momentum in multiphoton ionization.

The balance of the linear photon momentum in multiphoton ionization is studied experimentally. In the experiment argon and neon atoms are singly ionized by circularly polarized laser pulses with a wavelength of 800 and 1400 nm in the intensity range of 10(14)-10(15)  W/cm2. The photoelectrons are measured using velocity map imaging.

Precise in-situ measurement of laser pulse intensity using strong field ionization.

Building on the work of Alnaser et al. [Phys. Rev.

Direct test of laser tunneling with electron momentum imaging.

Tunneling is often used to describe multiphoton ionization of rare gas atoms in infrared fields. We test the tunneling approximation and its nonadiabatic extension by measuring the unperturbed momentum distribution along the κ direction of a circularly polarized light pulse. We find substantial, but not total, agreement between our results and the predictions of the model.

Bioaccumulation of persistent organic pollutants in female common dolphins (Delphinus delphis) and harbour porpoises (Phocoena phocoena) from western European seas: geographical trends, causal factors and effects on reproduction and mortality.

Concentrations of polychlorinated biphenyls (PCBs) in blubber of female common dolphins and harbour porpoises from the Atlantic coast of Europe were frequently above the threshold at which effects on reproduction could be expected, in 40% and 47% of cases respectively. This rose to 74% for porpoises from the southern North Sea. PCB concentrations were also high in southern North Sea fish.

Delineation of moving targets with slow MVCT scans: implications for adaptive non-gated lung tomotherapy.

Accurate imaging is a prerequisite for adaptive radiation therapy of mobile tumours. We present an evaluation of the performance of slow computed tomography (CT) for mapping and delineating the excursion boundary of a moving object using a tumour phantom scanned with the helical MVCT scanner of a tomotherapy unit. A spherical test object driven by sinusoidal motion in both the lateral and cranial-caudal directions was used to determine how well MVCT images depict the true envelope of the motion.

Neurodevelopmental defects resulting from ATRX overexpression in transgenic mice.

Several X-linked mental retardation syndromes are caused by mutations in the ATRX gene. Common clinical features associated with ATRX mutations include severe mental retardation, characteristic facial anomalies and variable degrees of urogenital defects and alpha-thalassemia. Although the ATRX protein is a member of the SWI/SNF family of chromatin remodeling proteins, little is known about the biochemical activity of the ATRX protein or its in vivo function during development.

Cell cycle-dependent phosphorylation of the ATRX protein correlates with changes in nuclear matrix and chromatin association.

Mutations in the ATRX gene are associated with an X-linked mental retardation (XLMR) syndrome most often accompanied by alpha-thalassaemia (ATR-X syndrome). The ATRX gene encodes a predicted protein of 280 kDa featuring a PHD zinc finger motif and an ATPase/helicase domain of the SWI/SNF type; the vast majority of mutations in the ATRX gene fall within these two motifs. Although these domains are suggestive of a role for ATRX in transcriptional regulation by affecting chromatin structure and/or function, the precise cellular role of the ATRX protein remains undefined.

Postmortem investigations on winter stranded sperm whales from the coasts of Belgium and The Netherlands.

During winter 1994-95, four and three sperm whales (Physeter macrocephalus) were stranded along the Belgian and the Dutch coasts, respectively. Necropsies and tissue samplings were collected 24 hrs post mortem. Lesions on several whales included round and linear skin scars, ventral skin abrasions, acute skin ulcers, acute ulcerative stomatitides, acute to chronic external otitides, and passive visceral congestion.

Mutations in the hemagglutinin and matrix genes of a virulent influenza virus variant, A/FM/1/47-MA, control different stages in pathogenesis.

The mouse adapted strain of influenza A/FM/1/47 virus, FM-MA, has increased virulence due to mutations in HA, M1 and at least one other, unmapped, genome segment. Genetic reassortants that differ due to the HA or M1 mutations were used to define the role of these mutations in pathogenesis. Pathological changes in lungs of infected mice were assessed by hematoxylin phloxine saffron (HPS) staining, and viral infection was measured by fluorescent antibody staining of thin sections and flow cytometry of lung parenchymal cells.

Polychlorinated Biphenyls, Dibenzo-p-dioxins, and Dibenzofurans in Harbor Porpoises (Phocoena phocoena) Stranded on the Dutch Coast Between 1990 and 1993.

Congener-specific polychlorinated biphenyl (PCB) concentrations were determined in the blubber, kidney, and liver tissues of 22 harbor porpoises (Phocoena phocoena) stranded on the Dutch coast. For comparison, the PCB concentrations in blubber and liver samples of four porpoises from the vicinity of Greenland were investigated. In ten blubber samples, the non-ortho PCB concentrations were determined, while in four of these the levels of chlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) were analyzed.

The influenza virus variant A/FM/1/47-MA possesses single amino acid replacements in the hemagglutinin, controlling virulence, and in the matrix protein, controlling virulence as well as growth.

Genetic analysis of mouse-adapted influenza virus variant A/FM/1/47 (FM) MA has previously identified four genome segments, 4, 5, 7, and 8, that are statistically associated with virulence. On sequencing these genome segments, we found single amino acid replacements at amino acid 47 of the HA2 subunit of the hemagglutinin and at amino acid 139 of the matrix protein. Mutation was not detected in segments 5 and 8, obviating a role for these genes in FM-MA virulence.

[The position of seals in the system of mammals (author's transl)].

The common seal Phoca vitulina belongs to the order Pinnipedia, a group of marine mammals, the majority of which live in the colder seas. Two main groups are differentiated within this order: Otarioidea and Phocoidea. The Otarioidea are divided into two families: Otariidae (sea lions and fur seals) and Odobenidae (walruses): the Phocoidea consist of the family Phocidae (seals) only.