A New Look at Bonding in Trialuminides: Reinvestigation of TaAl3

Single crystals of TaAl3 were grown at high temperatures from an Al-rich, binary solution. TaAl3 adopts the D022 structure type, space group I4/mmm with a = 3.8412(5) Å, c = 8.5402(17) Å, and Z = 2. The structure type, which is the preferred structure for all group 5 trialuminides and TiAl3 as well as the high-temperature form of HfAl3, is a binary coloring of the face-centered-cubic (fcc) arrangement. The distribution of Ta atoms creates a three-dimensional network of vertex and edge-sharing square pyramids of Al atoms. Temperature-dependent electrical resistivity and magnetic susceptibility measurements are consistent with TaAl3 being a metallic compound with a relatively low density of states at the Fermi surface. Furthermore, tight-binding electronic structure calculations are utilized to describe the bonding in these compounds and to compare their stability with respect to the alternative fcc-related, e.g., the D023 (ZrAl3-type) and the L12 (AuCu3-type), structures. A modified Wade\u27s rule argument provides insights into the structural preferences

Quasi 1-dimensional photonic crystals as building block for compact integrated optical sensors

A quasi one-dimensional photonic crystal has been fabricated and the applicability of this kind of structure for optical sensing has been investigated by measuring the transmission spectra as a function of the cladding refractive index. The cladding index was varied using a liquid flow, of which the index was slowly varied over a small range. The shift with cladding index of the steep stop band edge provides a relatively sensitive detection mechanism in an extremely compact device

Weyl group multiple Dirichlet series constructed from quadratic characters

We construct multiple Dirichlet series in several complex variables whose coefficients involve quadratic residue symbols. The series are shown to have an analytic continuation and satisfy a certain group of functional equations. These are the first examples of an infinite collection of unstable Weyl group multiple Dirichlet series in greater than two variables.Comment: incorporated referee's comment

Lamellar Phase of Stacked Two-Dimensional Rafts of Actin Filaments

We examined liquid crystalline phases of the cytoskeletal polyelectrolyte filamentous (F-)actin in the presence of multivalent counterions. As a function of increasing ion concentration, the F-actin rods in either an isotropic or a nematic phase will transform into a new and unexpected lamellar phase of crosslinked rafts (LXR phase), before condensing into a bundled phase of parallel, close-packed rods. This behavior is generic for alkali earth divalent ions Mg2+, Ca2+, Sr2+, and Ba2+, and the structural transitions are achieved without any architecture-specific actin-binding linker proteins

On the evolution of cosmic-superstring networks

We model the behaviour of a network of interacting (p,q) strings from IIB string theory by considering a field theory containing multiple species of string, allowing us to study the effect of non-intercommuting events due to two different species crossing each other. This then has the potential for a string dominated Universe with the network becoming so tangled that it freezes. We give numerical evidence, explained by a one-scale model, that such freezing does not take place, with the network reaching a scaling limit where its density relative to the background increases with N, the number of string types.Comment: Extra references added showing constraints on cosmic superstrings, 7 pages, 7 figure

Feasibility and patient’s experiences of perioperative telemonitoring in major abdominal surgery:an observational pilot study

Background: Telemonitoring during the perioperative trajectory may improve patient outcomes and self-management. The aim of this study is to assess the feasibility of and patient’s experiences with telemonitoring before and after major abdominal surgery to inform future study design. Methods: Patients planned for elective major abdominal surgery wore a sensor and answered well-being questions on a tablet daily for at least 2 weeks preoperatively up to 30-days postoperatively. Feasibility was assessed by participation and completion rate, compliance per day, weekly satisfaction scores, and reasons for nonscheduled contact. Results: Twenty-three patients were included (participation rate of 54.5%) with a completion rate of 69.6%. Median compliance with the wearable sensor and well-being questions was respectively: 94.7% and 83.3% preoperatively at home; 100% and 66.7% postoperatively in-hospital; and 95.4% and 85.8% postoperatively at home. Median weekly satisfaction scores for both wearing the sensor and well-being questions were 5 (IQR, 4–5). Contact moments were related to absence of sensor data and technological issues (76.0%) or patient discomfort and insecurity (24.0%). Conclusions: In this study, telemonitoring showed high satisfaction and compliance during the perioperative trajectory. Future trial design regarding the effectiveness of telemonitoring requires embedding in clinical practice and support for patients, relatives, and healthcare personnel

Seeking Evolution of Dark Energy

We study how observationally to distinguish between a cosmological constant (CC) and an evolving dark energy with equation of state $\omega(Z)$. We focus on the value of redshift Z* at which the cosmic late time acceleration begins and $\ddot{a}(Z^{*}) = 0$. Four $\omega(Z)$ are studied, including the well-known CPL model and a new model that has advantages when describing the entire expansion era. If dark energy is represented by a CC model with $\omega \equiv -1$, the present ranges for $\Omega_{\Lambda}(t_0)$ and $\Omega_m(t_0)$ imply that Z* = 0.743 with 4% error. We discuss the possible implications of a model independent measurement of Z* with better accuracy.Comment: 9 pages, LaTeX, 5 figure

Routine abdominal ultrasonography has limited value in the care for patients with indolent systemic mastocytosis

Objectives: Systemic mastocytosis (SM) is a myeloproliferative disease characterized by the accumulation of aberrant mast cells. Since advanced subtypes of SM can lead to organ dysfunction and shortened survival, timely recognition of progressive disease is important for the adequate treatment of SM patients. Methods: Here, we report the results of our cohort study on the value of routine abdominal ultrasonography for the detection of progression of indolent systemic mastocytosis (ISM). Results: We included 88 patients with ISM, of whom 9 developed new hepatosplenomegaly during follow-up. In this group, the median serum tryptase level increased by 11.60 μg/l, compared with a decrease of −0.20 μg/l in the 79 patients with unchanged ultrasonography results (p = 0.016). A change in liver and/or spleen size never led to a change in clinical classification, nor management. Discussion: Based on the finding that a change in ultrasonography findings did not correlate to disease progression in general, it appears that isolated hepatosplenomegaly does not have prognostic implications in patients with ISM. Conclusions: Routine abdominal ultrasonography is redundant in the follow-up of patients with ISM. A combination of physical examination with serum tryptase levels can be used to screen for hepatosplenomegaly