Investigating CXOU J163802.6-471358: a new pulsar wind nebula in the Norma region?

We present the first analysis of the extended source CXOU J163802.6--471358, which was discovered serendipitously during the {\em Chandra} X-ray survey of the Norma region of the Galactic spiral arms. The X-ray source exhibits a cometary appearance with a point source and an extended tail region. The complete source spectrum is fitted well with an absorbed power law model and jointly fitting the {\em Chandra} spectrum of the full source with one obtained from an archived {\em XMM-Newton} observation results in best fit parameters $N_{\rm H}$ $=1.5^{+0.7}_{-0.5}\times10^{23} \text{cm}{^{-2}}$ and $\Gamma=1.1^{+0.7}_{-0.6}$ (90$$ confidence uncertainties). The unabsorbed luminosity of the full source is then $L_X\sim 4.8\times10^{33}d_{10}^2$ergs s$^{-1}$ with $d_{10}=d/10$kpc, where a distance of 10 kpc is a lower bound inferred from the large column density. The radio counterpart found for the source using data from the Molonglo Galactic Plane Survey epoch-2 (MGPS-2) shows an elongated tail offset from the X-ray emission. No infrared counterpart was found. The results are consistent with the source being a previously unknown pulsar driving a bow shock through the ambient medium

Photonic crystal fiber with a hybrid honeycomb cladding

We consider an air-silica honeycomb lattice and demonstrate a new approach to the formation of a core defect. Typically, a high or low-index core is formed by adding a high-index region or an additional air-hole (or other low-index material) to the lattice, but here we discuss how a core defect can be formed by manipulating the cladding region rather than the core region itself. Germanium-doping of the honeycomb lattice has recently been suggested for the formation of a photonic band-gap guiding silica-core and here we experimentally demonstrate how an index-guiding silica-core can be formed by fluorine-doping of the honeycomb lattice.Comment: 5 pages including 3 figures. Accepted for Optics Expres

Investigations of lubricant rheology as applied to elastohydrodynamic lubrication

The pressure viscometer was modified to permit the measurement of viscosity at elevated pressures and shear stresses up to 5 x 10 to the 6th power N/sq m (720 psi). This shear stress is within a factor of three of the shear stress occurring in a sliding ehd point contact such as occurs in the ehd simulator. Viscosity data were taken on five lubricant samples, and it was found that viscous heating effects on the viscosity were predominant and not non-Newtonian behavior at the high shear stresses. The development of the infrared temperature measuring technique for the ehd simulator was completed, and temperature data for a set of operating conditions and one lubricant are reported. The numerical analysis of the behavior of nonlinear lubricants in the lubrication of rollers is reported

Asperity deformation during running-in

Asperities loaded in pure rolling against a hard, smooth surface will often be deformed at the first contact event and will thereby experience high normal stress, presumably of a magnitude near the Vickers hardness of the softer material. Continued running-in can be imagined to develop into lower stress levels and an increase of contact area. An asperity model simulating a running-in process of rough surfaces with lengthy protractions in the rolling direction was investigated. After a limited range of only about 104 contact events a state of very low deformation rate was found

Later is not necessarily better: limitations of survival analysis in studies of long-term drug treatment of psychiatric conditions

Survival analysis is routinely used to assess differences between groups in relapse prevention and treatment discontinuation studies involving people with long-term psychiatric conditions. The actual outcome in survival analysis is 'time to event', yet, in the mental health field, there has been little consideration of whether a temporary delay to relapse is clinically relevant in a condition that can last for decades. Moreover, in psychiatric drug trials, a pattern of elevated early relapses following randomisation to placebo or no treatment is common. This may be the result of the withdrawal of previous treatment leading to physiological withdrawal effects, which may be mistaken for relapse, or genuine relapse precipitated by the process of withdrawal. Such withdrawal effects typically produce converging survival curves eventually. They inevitably lead to differences in time to relapse, even when there is little or no difference in the cumulative risk of relapse at final follow-up. Therefore, statistical tests based on survival analyses can be misleading because they obscure these withdrawal effects. We illustrate these difficulties in a trial of antipsychotic reduction versus maintenance, and a trial of prophylactic esketamine in people with treatment-resistant depression. Both illustrate withdrawal-related effects that underline the importance of long-term follow-up and question the use of tests based on time to event. Further discussion of the most relevant outcome and appropriate approach to analysis, and research on patient and carer preferences is important to inform the design of future trials and interpretation of existing ones

Integrated production of tree biomass and piglets - Effect of paddock design on sow excretory behaviour

In systems with an integrated production of trees and piglets it is important that the lactating sows are motivated to urinate and defecate adjacent to the trees to reduce nutrient losses. Adding poplar trees in one end of individual pasture-based paddocks did not motivate the sows to choose the area with trees for elimination independent of paddock design. The location of feed and hut influenced the sows’ excretory behaviour and the effect differed between the different combination of feed and hut location. Future work should focus further on overall paddock design to optimize nutrient uptake and to ensure an outdoor system that from both a welfare- and environmentally point of view is sustainable

Collective discussions for the development of Interpretative Knowledge in Mathematics Teacher Education

We start from the assumption that teachers need a deep and broad mathematical knowledge —called Interpretative Knowledge (IK)—that allows them to support students in building their mathematical knowledge from their own reasoning and productions. In the present study, we aimed to ascertain how collective discussions focusing on the interpretation of students’ productions engage Prospective Teachers (PTs) and impact their IK development. In particular, we observe how this form of collaborative work among PTs allows for the emergence of novel insights into the mathematical aspects of students’ productions that were not considered during previous individual work, and produce changes in PTs’ attitudes towards students’ productions