Real-Time Planning with Primitives for Dynamic Walking over Uneven Terrain

We present an algorithm for receding-horizon motion planning using a finite family of motion primitives for underactuated dynamic walking over uneven terrain. The motion primitives are defined as virtual holonomic constraints, and the special structure of underactuated mechanical systems operating subject to virtual constraints is used to construct closed-form solutions and a special binary search tree that dramatically speed up motion planning. We propose a greedy depth-first search and discuss improvement using energy-based heuristics. The resulting algorithm can plan several footsteps ahead in a fraction of a second for both the compass-gait walker and a planar 7-Degree-of-freedom/five-link walker.Comment: Conference submissio

Photochromic control of nucleic acid systems through anthracene photodimerisation

The focus of this project has involved the incorporation of non-nucleosidic anthracene phosphoramidites into oligonucleotide sequences for the purpose of studying anthracene photodimerisation and its effect on DNA structure and function. The primary aim of the research was to use this technique as a method of disrupting hybridisation between complementary oligonucleotides. By introducing two anthracene tags into the same oligonucleotide sequence it is possible to initiate a reversible, light-induced reaction involving the intramolecular dimerisation of the appended anthracene groups. The resulting change in structure, combined with a change in π-stacking interactions within the oligonucleotide, alters the binding towards the complementary sequence. This effect was studied through a number of techniques including variable temperature UV, CD and fluorescence spectroscopy and gel electrophoresis. A range of studies have been employed that utilise this technique, principally investigating whether the release of a bound complementary oligonucleotide can be achieved by completely destabilising the intermolecular interactions. However the study has been expanded to investigate known G-quadruplex sequences and how their interactions with proteins can be altered. Finally the intermolecular photodimerisation between two anthracene modified oligonucleotides was investigated in order to create temporary cross links, which can help stabilise the duplex structure

Original Climax Films: historicizing the British hardcore pornography film business

This article presents findings from my research into the British hardcore pornography business. Porn studies has given little coverage to the British pornography business, with much of the academic literature focusing on the American adult entertainment industry. Recently, there has been a rising interest in the historical framework of porn cinemas both in popular culture and in academic work. This article contributes to this debate, taking both a cultural and an economic approach to explore the conditions that led to the emergence of British hardcore production as an alternative economy in the 1960s. In this economy, entrepreneurs make use of new technologies to produce artefacts that are exchanged for an economic benefit, while circumventing laws to distribute their artefacts. To historicize this economy, I draw on ethnohistorical research, which includes interviews with people involved in the British hardcore business and archival research. I argue that a combination of glamour filmmaking, a relaxation of political and cultural attitudes towards sexuality, the location of Soho, London, and emerging technologies for producing films collectively contribute to the emergence of an alternative economy of British hardcore production. I focus specifically on the practices of two entrepreneurs within this economy, Ivor Cook and Mike Freeman, considering how their actions inadvertently created the British hardcore film business, and played a significant role in the development of hardcore production outside of the United Kingdom

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Identification of externally positive systems

We consider identification of externally positive linear discrete-time systems from input/output data. The proposed method is formulated as a semidefinite program, and is guaranteed to identify models that are ellipsoidal cone-invariant and, consequently, externally positive. We demonstrate empirically that this cone-invariance approach can significantly reduce the conservatism associated with methods that enforce internal positivity as a sufficient condition for external positivity

Using automated active infrared counters to estimate footfall on urban park footpaths: reliability and validity testing - Supporting Dataset

This sheet contains the refined data used to calculate intraclass correlations for active infrared counter reliability assessments and validity assessments. There are 13-weeks of active infrared footfall counts per season and these have been used to calculate median footfall for all possible 1, 2, 3, and 4-week combinations. These combinations are replicated for three counters within an UK urban park