This paper concerns trajectory tracking control of attitude dynamics configured on SU(2). Inspired by a popular geometric tracking controller on SO(3), differential geometric tools are used to derive both continuous and discontinuous attitude controllers on the SU(2) manifold, relating these to preexisting controllers operating with imaginary quaternion errors. Additionally, a robustness result is

We exploit knowledge of linear substructure in the linear-regression Kalman filters (LRKFs) to simplify the problem of moment matching. The theoretical results yield quantifiable and significant computational speedups at no cost of estimation accuracy, assuming partially linear estimation models. The results apply to any symmetrical LRKF, and reductions in computational complexity are stated as a

We present a tracking controller for quadrotor UAVs which uses partial state information and filters measurement noise. We show uniform almost global and locally exponential asymptotic stability of the resulting closed-loop system, which implies robustness against bounded disturbances. We illustrate the performance of the controller by means of several numerical examples, including a complex loopi

This paper considers coordination control of double-integrator systems and proposes general control laws involving time-varying inputs. The nominal control input is weighted by time-varying (time-dependent or state-dependent) positive definite matrices, providing more freedoms in defining the control tasks. We present sufficient conditions to ensure the asymptotic convergence of double-integrator

Background: Little is known of possible gender differences in treatment of periampullary tumours and outcome after pancreatoduodenectomy (PD), and the aim of this study was therefore to investigate any variances from national multicentre perspective. Methods: Data from the Swedish National Registry for Pancreatic and Periampullary Cancer for all patients diagnosed with a periampullary tumour from

Under the application of longitudinal electric fields in microchannels, microparticles experience lift forces that push them away from the channel walls and affect their trajectories. At high frequencies (>100KHz) the dielectrophoretic forces dominate and are well understood but at lower frequencies there is little agreement as to the exact nature of the forces, how they are generated and how they

High throughput in particle and molecular sorting schemes is an important performance indicator and can be realized through increased volumetric processing rates or increased concentrations. Here we investigate the effect of increased concentration of high-molecular weight DNA in micropillar arrays for deterministic lateral displacement (DLD). We find that the array imposes regular fluctuations in

Transfer RNAs (tRNAs) are central adaptors that decode genetic information during translation and have been long considered static cellular components. However, whether dynamic changes in tRNAs and tRNA-derived fragments actively contribute to gene regulation remains debated. In this issue, Huh et al (2020) highlight tyrosine tRNAGUA fragmentation at the nexus of an evolutionarily conserved adapti

Proper compensation during foreclosure is essential to any effort to protect borrowers as consumers. However, the effectiveness of consumer protection and other safety nets during foreclosure has been debated within academia. This study contributes to this debate by exploring socio-economic group differences related to the compensatory potential of foreclosure proceedings. It employs micro-level d

Inspired by the NP-hardness of string folding problems modeling the natural process of protein folding, we discuss the idea of solving instances of NP-hard problems (e.g., string folding problems) of moderate size by letting artificially assembled proteins to fold. The accuracy with which one can combinatorially model the protein folding process, e.g., by string folding, as well as the precision w

Nanowires and nanotubes are very promising tools for biological applications. Their small dimensions, which are on the same length scale as many cell components, make them an ideal tool to probe and stimulate cells with minimal perturbation. Here, we present a review of our work towards using nanowires and nanotubes for biomedical applications, such as neural implant, mechanosensing, and cell tran

This paper examines an artefact type of unknown function, found in several places across medieval England. These artefacts are mostly made from goose radii, but other species, such as chicken and hare, are also known. The worked radii have often been interpreted as being related to writing, but a closer examination suggests that they are more likely to be awls.

This paper tests how gender stereotypes may result in biased student evaluations of teaching (SET). We thereby contribute to an ongoing discussion about the validity and use of SET in academia. According to social psychological theory, gender biases in SET may occur because of a lack of fit between gender stereotypes, and the professional roles individuals engage in. A lack of fit often leads to m

A State of the Art lecture titled “The role of platelets in sepsis” was presented at the ISTH congress in 2020. Sepsis is a life-threatening organ dysfunction caused by a dysregulated and multifaceted host response to infection. Platelets play a significant role in the coordinated immune response to infection and therefore in the inflammation and coagulation dysfunction that contributes to organ d

Objectives: The National Institutes of Health Stroke Scale (NIHSS) has not been validated to diagnose aphasia in the stroke population. We therefore examined the diagnostic accuracy of NIHSS for detecting aphasia in acute ischemic stroke. Methods: Consecutive patients with acute first-ever ischemic stroke were included prospectively in Lund Stroke Register Study at Skåne University Hospital, Swede

In 1833-1874, Spain suffered 0.7 coups per year. By contrast, the Restoration (1874-1923) saw the eradication of successful coups. This can be partially attributed to the turno pacífico, which allowed the main political parties to alternate in office without dragging the military into politics. We suggest, however, that the reduction in coup risk was also associated with a conscious budget policy.

The traditional method for recycling brass chips is to send the scrap back to the material manufacturer for re-melting. Alternatively, brass chips can be reclaimed through hot forging operations at the production site. As an initial screening of the environmental impact of this novel reclamation method, the impacts of this new method was compared to conventional brass production (including recycli

Purpose: To explore associations between the characteristics of people with epilepsy (PWE) and their attitudes toward generic substitution of antiseizure drugs (ASDs) in epilepsy. Methods: This was a cross-sectional survey study directed at adults with epilepsy using selected brand drugs: Keppra®, Lamictal®, Lyrica® or Topimax®. Symptoms of anxiety and depression, sense of self-efficacy, and belie