Showing papers by "University of Lincoln published in 2014"

The design and function of birds' nests

Abstract: All birds construct nests in which to lay eggs and/or raise offspring. Traditionally, it was thought that natural selection and the requirement to minimize the risk of predation determined the design of completed nests. However, it is becoming increasingly apparent that sexual selection also influences nest design. This is an important development as while species such as bowerbirds build structures that are extended phenotypic signals whose sole purpose is to attract a mate, nests contain eggs and/or offspring, thereby suggesting a direct trade-off between the conflicting requirements of natural and sexual selection. Nest design also varies adaptively in order to both minimize the detrimental effects of parasites and to create a suitable microclimate for parents and developing offspring in relation to predictable variation in environmental conditions. Our understanding of the design and function of birds' nests has increased considerably in recent years, and the evidence suggests that nests have four nonmutually exclusive functions. Consequently, we conclude that the design of birds' nests is far more sophisticated than previously realized and that nests are multifunctional structures that have important fitness consequences for the builder/s.

Gauss-Newton Deformable Part Models for Face Alignment In-the-Wild

Abstract: Arguably, Deformable Part Models (DPMs) are one of the most prominent approaches for face alignment with impressive results being recently reported for both controlled lab and unconstrained settings. Fitting in most DPM methods is typically formulated as a two-step process during which discriminatively trained part templates are first correlated with the image to yield a filter response for each landmark and then shape optimization is performed over these filter responses. This process, although computationally efficient, is based on fixed part templates which are assumed to be independent, and has been shown to result in imperfect filter responses and detection ambiguities. To address this limitation, in this paper, we propose to jointly optimize a part-based, trained in-the-wild, flexible appearance model along with a global shape model which results in a joint translational motion model for the model parts via Gauss-Newton (GN) optimization. We show how significant computational reductions can be achieved by building a full model during training but then efficiently optimizing the proposed cost function on a sparse grid using weighted least-squares during fitting. We coin the proposed formulation Gauss-Newton Deformable Part Model (GN-DPM). Finally, we compare its performance against the state-of-the-art and show that the proposed GN-DPM outperforms it, in some cases, by a large margin. Code for our method is available from http://ibug.doc.ic.ac.uk/resources

A Practical Multirobot Localization System

Abstract: We present a fast and precise vision-based software intended for multiple robot localization. The core component of the software is a novel and efficient algorithm for black and white pattern detection. The method is robust to variable lighting conditions, achieves sub-pixel precision and its computational complexity is independent of the processed image size. With off-the-shelf computational equipment and low-cost cameras, the core algorithm is able to process hundreds of images per second while tracking hundreds of objects with millimeter precision. In addition, we present the method's mathematical model, which allows to estimate the expected localization precision, area of coverage, and processing speed from the camera's intrinsic parameters and hardware's processing capacity. The correctness of the presented model and performance of the algorithm in real-world conditions is verified in several experiments. Apart from the method description, we also make its source code public at http://purl.org/robotics/whycon ; so, it can be used as an enabling technology for various mobile robotic problems.

The pattern of Middle East respiratory syndrome coronavirus in Saudi Arabia: a descriptive epidemiological analysis of data from the Saudi Ministry of Health

Abstract: Purpose: This study describes the epidemiology of Middle East respiratory syndrome coronavirus (MERS-CoV) in Saudi Arabia. Patients and methods: Epidemiological analysis was performed on data from all MERS-CoV cases recorded by the Saudi Ministry of Health between June 6, 2013 and May 14, 2014. The frequency of cases and deaths was calculated and adjusted by month, sex, age group, and region. The average monthly temperature and humidity of infected regions throughout the year was also calculated. Results: A total of 425 cases were recorded over the study period. The highest number of cases and deaths occurred between April and May 2014. Disease occurrence among men (260 cases [62%]) was higher than in women (162 cases [38%]), and the case fatality rate was higher for men (52%) than for women (23%). In addition, those in the 45–59 years and ≥60 years age groups were most likely to be infected, and the case fatality rate for these people was higher than for other groups. The highest number of cases and deaths were reported in Riyadh (169 cases; 43 deaths), followed by Jeddah (156 cases; 36 deaths) and the Eastern Region (24 cases; 22 deaths). The highest case fatality rate was in the Eastern Region (92%), followed by Medinah (36%) and Najran (33%). MERS-CoV infection actively causes disease in environments with low relative humidity (<20%) and high temperature (15°C–35°C). Conclusion: MERS-CoV is considered an epidemic in Saudi Arabia. The frequency of cases and deaths is higher among men than women, and those above 45 years of age are most affected. Low relative humidity and high temperature can enhance the spread of this disease in the entire population. Further analytical studies are required to determine the source and mode of infection in Saudi Arabia.

Responses to social and environmental stress are attenuated by strong male bonds in wild macaques.

Abstract: In humans and obligatory social animals, individuals with weak social ties experience negative health and fitness consequences. The social buffering hypothesis conceptualizes one possible mediating mechanism: During stressful situations the presence of close social partners buffers against the adverse effects of increased physiological stress levels. We tested this hypothesis using data on social (rate of aggression received) and environmental (low temperatures) stressors in wild male Barbary macaques (Macaca sylvanus) in Morocco. These males form strong, enduring, and equitable affiliative relationships similar to human friendships. We tested the effect of the strength of a male’s top three social bonds on his fecal glucocorticoid metabolite (fGCM) levels as a function of the stressors’ intensity. The attenuating effect of stronger social bonds on physiological stress increased both with increasing rates of aggression received and with decreasing minimum daily temperature. Ruling out thermoregulatory and immediate effects of social interactions on fGCM levels, our results indicate that male Barbary macaques employ a tend-and-befriend coping strategy in the face of increased environmental as well as social day-to-day stressors. This evidence of a stress-ameliorating effect of social bonding among males under natural conditions and beyond the mother–offspring, kin or pair bond broadens the generality of the social buffering hypothesis.

Sleep restriction therapy for insomnia is associated with reduced objective total sleep time, increased daytime somnolence, and objectively impaired vigilance: implications for the clinical management of insomnia disorder.

Abstract: Aims: Adverse-effects of psychological therapies are rarely recorded or considered Sleep Restriction Therapy (SRT), an effective component of cognitive-behavioral therapy for insomnia, limits time-in-bed and may result in reduced total sleep time Clinical evidence suggests that daytime impairment may be experienced by patients in the acute treatment period, yet there has been little systematic study of this possibility Here, we investigated whether SRT is associated with reduced total sleep time, increased daytime somnolence and impaired vigilance Design: Within-subjects, repeated measures treatment investigation with the addition of a matched good sleeper control group to permit between-group comparisons on performance measures Setting: Sleep Research Laboratory Participants: Sixteen patients [10 female, Mean Age = 471 (108) yrs] with well defined psychophysiological insomnia (PI) and an age and gender-matched control group of good sleepers [GS, n=15; 10 female, mean age = 471 (105) yrs] Interventions: Patients were treated with single component SRT over a 4-week protocol, comprising one main session for treatment delivery and weekly sleep window titration (weeks 1-4) Patients slept in the laboratory for two nights prior to treatment initiation and for three nights (SRT night 1, 8, 22) during the acute interventional phase In addition, those with PI completed the psychomotor vigilance task (PVT) at seven defined time-points [day 0 (baseline), day 1,7,8,21,22 (acute treatment) and day 84 (3 months)] The Epworth Sleepiness Scale (ESS) was completed at baseline, weeks 1-4, and at three months Matched good sleepers completed the PVT at one single time-point to permit baseline performance comparisons with patients Measurement and results: Subjective sleep outcomes and global insomnia severity significantly improved pre-to-post SRT There was, however, a decrease in PSG defined total sleep time during acute implementation of SRT, by an average of 91 minutes on night 1, 78 minutes on night 8, and 69 minutes on night 22, relative to baseline (p’s<001; effect size range=160-180) During SRT, PVT lapses were significantly increased from baseline (at 3/5 assessment points, all p<05; effect size range=69-77), returning to baseline levels by three months (p=43) A similar pattern was observed for RT, with RTs slowing during acute treatment (at 4/5 assessment points, all p<05; effect size range=57-89) and returning to pre-treatment levels at three months (p=88) While patients did not differ from good sleepers at baseline with respect to PVT performance (p’s<20), between-group differences began to emerge during SRT, with patients showing relative impairment Objective measures were paralleled by significant elevations in subjective daytime sleepiness at weeks 1, 2, and 3 (relative to baseline; all p<05); by three months, sleepiness had returned to baseline (normative) levels (p=65) Conclusion: For the first time we show that acute SRT is associated with reduced total sleep time, increased daytime sleepiness and objective performance impairment Our data have important implications for implementation guidelines around the safe and effective delivery of CBT-I

Baby schema in human and animal faces induces cuteness perception and gaze allocation in children.

Abstract: The baby schema concept was originally proposed as a set of infantile traits with high appeal for humans, subsequently shown to elicit caretaking behavior and to affect cuteness perception and attentional processes However, it is unclear whether the response to the baby schema may be extended to the human-animal bond context Moreover, questions remain as to whether the cute response is constant and persistent or whether it changes with development In the present study we parametrically manipulated the baby schema in images of humans, dogs, and cats We analyzed responses of 3–6 year-old children, using both explicit (ie, cuteness ratings) and implicit (ie, eye gaze patterns) measures By means of eye-tracking, we assessed children’s preferential attention to images varying only for the degree of baby schema and explored participants’ fixation patterns during a cuteness task For comparative purposes, cuteness ratings were also obtained in a sample of adults Overall our results show that the response to an infantile facial configuration emerges early during development In children, the baby schema affects both cuteness perception and gaze allocation to infantile stimuli and to specific facial features, an effect not simply limited to human faces In line with previous research, results confirm human positive appraisal toward animals and inform both educational and therapeutic interventions involving pets, helping to minimize risk factors (eg, dog bites)

Ferroelectric tunnel junctions with graphene electrodes

Abstract: Ferroelectric tunnel junctions, where electrical transport occurs across two electrodes separated by a ferroelectric layer, could be used for future non-volatile computer memories. Here, the authors employ graphene as an electrode in tunnel junctions for interface-facilitated enhancement of device performance.

Targeted memory reactivation during slow wave sleep facilitates emotional memory consolidation.

Abstract: Study Objectives: To investigate the mechanisms by which auditory targeted memory reactivation (TMR) during slow wave sleep (SWS) influences the consolidation of emotionally negative and neutral memories. Design: Each of 72 (36 negative, 36 neutral) picture-location associations were encoded with a semantically related sound. During a subsequent nap, half of the sounds were replayed in SWS, before picture-location recall was examined in a final test. Setting: Manchester Sleep Laboratory, University of Manchester. Participants: 15 adults (3 male) mean age = 20.40 (standard deviation ± 3.07). Interventions: TMR with auditory cues during SWS. Measurements and Results: Performance was assessed by memory accuracy and recall response times (RTs). Data were analyzed with a 2 (sound: replayed/not replayed) × 2 (emotion: negative/neutral) repeated measures analysis of covariance with SWS duration, and then SWS spindles, as the mean-centered covariate. Both analyses revealed a significant three-way interaction for RTs but not memory accuracy. Critically, SWS duration and SWS spindles predicted faster memory judgments for negative, relative to neutral, picture locations that were cued with TMR. Conclusions: TMR initiates an enhanced consolidation process during subsequent SWS, wherein sleep spindles mediate the selective enhancement of reactivated emotional memories.

PEGylated nanomedicines: recent progress and remaining concerns

Abstract: Introduction: Recent biopharma deals related to nanocarrier drug delivery technologies highlight the emergence of nanomedicine. This is perhaps an expected culmination of many years of research demonstrating the potential of nanomedicine as the next generation of therapeutics with improved performance. PEGylated nanocarriers play a key role within this field. Areas covered: The drug delivery advantages of nanomedicines in general are discussed, focusing on nanocarriers and PEGylated nanomedicines, including products under current development/clinical evaluation. Well-established drug delivery benefits of PEGylation (e.g., prolonged circulation) are only briefly covered. Instead, attention is deliberately made to less commonly reported advantages of PEGylation, including mucosal delivery of nanomedicines. Finally, some of the issues related to the safety of PEGylated nanomedicines in clinical application are discussed. Expert opinion: The advent of nanomedicine providing therapeutic options of refined perf...

Alternate endings: using fiction to explore design futures

Abstract: Design research and practice within HCI is inherently oriented toward the future. However, the vision of the future described by HCI researchers and practitioners is typically utility-driven and focuses on the short term. It rarely acknowledges the potentially complex social and psychological long-term consequences of the technology artefacts produced. Thus, it has the potential to unintentionally cause real harm. Drawing on scholarship that investigates the link between fiction and design, this workshop will explore "alternate endings" to contemporary HCI papers. Attendees will use fictional narratives to envision long-term consequences of contemporary HCI projects, as a means for engaging the CHI community in a consideration of the values and implications of interactive technology.

ATRX Dysfunction Induces Replication Defects in Primary Mouse Cells

Abstract: The chromatin remodeling protein ATRX, which targets tandem repetitive DNA, has been shown to be required for expression of the alpha globin genes, for proliferation of a variety of cellular progenitors, for chromosome congression and for the maintenance of telomeres. Mutations in ATRX have recently been identified in tumours which maintain their telomeres by a telomerase independent pathway involving homologous recombination thought to be triggered by DNA damage. It is as yet unknown whether there is a central underlying mechanism associated with ATRX dysfunction which can explain the numerous cellular phenomena observed. There is, however, growing evidence for its role in the replication of various repetitive DNA templates which are thought to have a propensity to form secondary structures. Using a mouse knockout model we demonstrate that ATRX plays a direct role in facilitating DNA replication. Ablation of ATRX alone, although leading to a DNA damage response at telomeres, is not sufficient to trigger the alternative lengthening of telomere pathway in mouse embryonic stem cells.

Pharmaceutical co-crystals – are we there yet?

Abstract: In the pharmaceutical arena it is agreed that co-crystals form a vital part of the solid-state toolbox, allowing the progression of novel compounds through the development pathway to patients and improving properties in older medicines. Sadly though, few co-crystals have made it to the market in the form of a new licensed product. This displays a disconnect between research effort and end product. For some time now it has been possible to determine the formation of co-crystals, by a variety of screening and analytical means; although it is recognised that there will always be phases that sit in the ‘greyer’ area of the salt-co-crystal continuum. It is also possible, with limitations, to predict the formation of co-crystals in silico via energetic and structural considerations. So what are the major hurdles and missing links, and what are the key structural properties we need to study to improve the success rate? This highlight hopes to address these.

Colias: An Autonomous Micro Robot for Swarm Robotic Applications:

Abstract: Robotic swarms that take inspiration from nature are becoming a fascinating topic for multi-robot researchers. The aim is to control a large number of simple robots enables them in order to solve common complex tasks. Due to the hardware complexities and cost of robot platforms, current research in swarm robotics is mostly performed by simulation software. Simulation of large numbers of these robots which are used in swarm robotic applications is extremely complex and often inaccurate due to poor modelling of external conditions. In this paper we present the design of a low-cost, open-platform, autonomous micro robot (Colias) for swarm robotic applications. Colias employs a circular platform with a diameter of 4 cm. It has a maximum speed of 35 cm/s that gives the ability to be used in swarm scenarios very quickly in large arenas. Long-range infrared modules with adjustable output power allow the robot to communicate with its direct neighbours from a range of 0.5 cm to 3 m. Colias has been designed as a complete platform with supporting software development tools for robotics education and research. It has been tested in individual and swarm scenarios and the observed results demonstrate its feasibility to be used as a micro sized mobile robot as well as a low-cost platform for robot swarm applications.

Range-wide multilocus phylogeography of the red fox reveals ancient continental divergence, minimal genomic exchange and distinct demographic histories

Abstract: Widely distributed taxa provide an opportunity to compare biogeographic responses to climatic fluctuations on multiple continents and to investigate speciation. We conducted the most geographically and genomically comprehensive study to date of the red fox (Vulpes vulpes), the world's most widely distributed wild terrestrial carnivore. Analyses of 697 bp of mitochondrial sequence in ~1000 individuals suggested an ancient Middle Eastern origin for all extant red foxes and a 400 kya (SD = 139 kya) origin of the primary North American (Nearctic) clade. Demographic analyses indicated a major expansion in Eurasia during the last glaciation (~50 kya), coinciding with a previously described secondary transfer of a single matriline (Holarctic) to North America. In contrast, North American matrilines (including the transferred portion of Holarctic clade) exhibited no signatures of expansion until the end of the Pleistocene (~12 kya). Analyses of 11 autosomal loci from a subset of foxes supported the colonization time frame suggested by mtDNA (and the fossil record) but, in contrast, reflected no detectable secondary transfer, resulting in the most fundamental genomic division of red foxes at the Bering Strait. Endemic continental Y-chromosome clades further supported this pattern. Thus, intercontinental genomic exchange was overall very limited, consistent with long-term reproductive isolation since the initial colonization of North America. Based on continental divergence times in other carnivoran species pairs, our findings support a model of peripatric speciation and are consistent with the previous classification of the North American red fox as a distinct species, V. fulva.

Spectral analysis for long-term robotic mapping

Abstract: This paper presents a new approach to mobile robot mapping in long-term scenarios. So far, the environment models used in mobile robotics have been tailored to capture static scenes and dealt with the environment changes by means of ‘memory decay’. While these models keep up with slowly changing environments, their utilization in dynamic, real world environments is difficult. The representation proposed in this paper models the environment’s spatio-temporal dynamics by its frequency spectrum. The spectral representation of the time domain allows to identify, analyse and remember regularly occurring environment processes in a computationally efficient way. Knowledge of the periodicity of the different environment processes constitutes the model predictive capabilities, which are especially useful for long-term mobile robotics scenarios. In the experiments presented, the proposed approach is applied to data collected by a mobile robot patrolling an indoor environment over a period of one week. Three scenarios are investigated, including intruder detection and 4D mapping. The results indicate that the proposed method allows to represent arbitrary timescales with constant (and low) memory requirements, achieving compression rates up to 106 . Moreover, the representation allows for prediction of future environment’s state with ∼ 90% precision.

Close but not too close: friendship as method(ology) in ethnographic research encounters

Abstract: “Friendship as method” is a relatively underexplored—and often unacknowledged—method, even within ethnographic inquiry. In this article, we consider the use of friendship as method in general, and situate this in relation to a specific ethnographic research project, which examined the lived experience of asthma amongst sports participants. The study involved researching individuals with whom the principal researcher had prior existing friendships. Via forms of confessional tales we explore some of the challenges encountered when attempting to negotiate the demands of the dual researcher-friend role, particularly during in-depth interviews. To illustrate our analysis, four sets of tales are examined, cohering around issues of: (1) attachment and when to “let go”; (2) interactional “game-play”; (3) “rescuing” participants; and (4) the need for researcher self-care when “things get too much.” The need to guard against merger with research participants-as-friends is also addressed. In analysing the tales, we draw upon insights derived from symbolic interactional analyses and in particular upon Goffman’s theoretical frameworks on interactional encounters.

Adaptive latitudinal variation in Common Blackbird Turdus merula nest characteristics

Abstract: Nest construction is taxonomically widespread, yet our understanding of adaptive intraspecific variation in nest design remains poor. Nest characteristics are expected to vary adaptively in response to predictable variation in spring temperatures over large spatial scales, yet such variation in nest design remains largely overlooked, particularly amongst open-cup-nesting birds. Here, we systematically examined the effects of latitudinal variation in spring temperatures and precipitation on the morphology, volume, composition, and insulatory properties of open-cup-nesting Common Blackbirds' Turdus merula nests to test the hypothesis that birds living in cooler environments at more northerly latitudes would build better insulated nests than conspecifics living in warmer environments at more southerly latitudes. As spring temperatures increased with decreasing latitude, the external diameter of nests decreased. However, as nest wall thickness also decreased, there was no variation in the diameter of the internal nest cups. Only the mass of dry grasses within nests decreased with warmer temperatures at lower latitudes. The insulatory properties of nests declined with warmer temperatures at lower latitudes and nests containing greater amounts of dry grasses had higher insulatory properties. The insulatory properties of nests decreased with warmer temperatures at lower latitudes, via changes in morphology (wall thickness) and composition (dry grasses). Meanwhile, spring precipitation did not vary with latitude, and none of the nest characteristics varied with spring precipitation. This suggests that Common Blackbirds nesting at higher latitudes were building nests with thicker walls in order to counteract the cooler temperatures. We have provided evidence that the nest construction behavior of open-cup-nesting birds systematically varies in response to large-scale spatial variation in spring temperatures.

Coordination and navigation of heterogeneous MAV-UGV formations localized by a 'hawk-eye'-like approach under a model predictive control scheme

Abstract: An approach for coordination and control of 3D heterogeneous formations of unmanned aerial and ground vehicles under hawk-eye-like relative localization is presented in this paper. The core of the method lies in the use of visual top-view feedback from flying robots for the stabilization of the entire group in a leader-follower formation. We formulate a novel model predictive control-based methodology for guiding the formation. The method is employed to solve the trajectory planning and control of a virtual leader into a desired target region. In addition, the method is used for keeping the following vehicles in the desired shape of the group. The approach is designed to ensure direct visibility between aerial and ground vehicles, which is crucial for the formation stabilization using the hawk-eye-like approach. The presented system is verified in numerous experiments inspired by search-and-rescue applications, where the formation acts as a searching phalanx. In addition, stability and convergence analyses are provided to explicitly determine the limitations of the method in real-world applications.

Epigenetic regulation of the placental HSD11B2 barrier and its role as a critical regulator of fetal development.

Abstract: "Fetal programming" is a term used to describe how early-life experience influences fetal development and later disease risk. In humans, prenatal stress-induced fetal programming is associated with increased risk of preterm birth, and a heightened risk of metabolic and neurological diseases later in life. A critical determinant of this is the regulation of fetal exposure to glucocorticoids by the placenta. Glucocorticoids are the mediators through which maternal stress influences fetal development. Excessive fetal glucocorticoid exposure during pregnancy results in low birth weight and abnormalities in a number of tissues. The amount of fetal exposure to maternal glucocorticoids depends on the expression of HSD11B2, an enzyme predominantly produced by the syncytiotrophoblast in the placenta. This protects the fetus by converting active glucocorticoids into inactive forms. In this review we examine recent findings regarding placental HSD11B2 that suggest that its epigenetic regulation may mechanistically link maternal stress and long-term health consequences in affected offspring.