Bayesian Optimisation for Safe Navigation under Localisation Uncertainty

In outdoor environments, mobile robots are required to navigate through terrain with varying characteristics, some of which might significantly affect the integrity of the platform. Ideally, the robot should be able to identify areas that are safe for navigation based on its own percepts about the environment while avoiding damage to itself. Bayesian optimisation (BO) has been successfully applied to the task of learning a model of terrain traversability while guiding the robot through more traversable areas. An issue, however, is that localisation uncertainty can end up guiding the robot to unsafe areas and distort the model being learnt. In this paper, we address this problem and present a novel method that allows BO to consider localisation uncertainty by applying a Gaussian process model for uncertain inputs as a prior. We evaluate the proposed method in simulation and in experiments with a real robot navigating over rough terrain and compare it against standard BO methods.Comment: To appear in the proceedings of the 18th International Symposium on Robotics Research (ISRR 2017

In vivo transcriptome analysis provides insights into host-dependent expression of virulence factors by Yersinia entomophaga MH96, during infection of Galleria mellonella

The function of microbes can be inferred from knowledge of genes specifically expressed in natural environments. Here, we report the in vivo transcriptome of the entomopathogenic bacterium Yersinia entomophaga MH96, captured during initial, septicemic, and pre-cadaveric stages of intrahemocoelic infection in Galleria mellonella. A total of 1285 genes were significantly upregulated by MH96 during infection; 829 genes responded to in vivo conditions during at least one stage of infection, 289 responded during two stages of infection, and 167 transcripts responded throughout all three stages of infection compared to in vitro conditions at equivalent cell densities. Genes upregulated during the earliest infection stage included components of the insecticidal toxin complex Yen-TC (chi1, chi2, and yenC1), genes for rearrangement hotspot element containing protein yenC3, cytolethal distending toxin cdtAB, and vegetative insecticidal toxin vip2. Genes more highly expressed throughout the infection cycle included the putative heat-stable enterotoxin yenT and three adhesins (usher-chaperone fimbria, filamentous hemagglutinin, and an AidA-like secreted adhesin). Clustering and functional enrichment of gene expression data also revealed expression of genes encoding type III and VI secretion system-associated effectors. Together these data provide insight into the pathobiology of MH96 and serve as an important resource supporting efforts to identify novel insecticidal agents

The Composition of Human Milk and Infant Faecal Microbiota Over the First Three Months of Life: A Pilot Study

peer-reviewedHuman milk contains a diverse array of bioactives and is also a source of bacteria for the developing infant gut. The aim of this study was to characterize the bacterial communities in human milk and infant faeces over the first 3 months of life, in 10 mother-infant pairs. The presence of viable Bifidobacterium and Lactobacillus in human milk was also evaluated. MiSeq sequencing revealed a large diversity of the human milk microbiota, identifying over 207 bacterial genera in milk samples. The phyla Proteobacteria and Firmicutes and the genera Pseudomonas, Staphylococcus and Streptococcus were the predominant bacterial groups. A core of 12 genera represented 81% of the microbiota relative abundance in milk samples at week 1, 3 and 6, decreasing to 73% at week 12. Genera shared between infant faeces and human milk samples accounted for 70–88% of the total relative abundance in infant faecal samples, supporting the hypothesis of vertical transfer of bacteria from milk to the infant gut. In addition, identical strains of Bifidobacterium breve and Lactobacillus plantarum were isolated from the milk and faeces of one mother-infant pair. Vertical transfer of bacteria via breastfeeding may contribute to the initial establishment of the microbiota in the developing infant intestine

USING BIRD STRIKE DATA TO MONITOR BIRD-HAZARD CONTROL

An effective definition of a bird strike is the basis for quantifying the scale of bird hazard problems. Here we present a working definition of a bird strike, which in turn forms the basis of an analysis of 32 years’ data collected at Dublin Airport, Ireland. A variety of datasets are analysed including the number of bird strikes per ten thousand aircraft movements, the mass of the bird species being struck, the time of year at which bird strikes occur and the dimensions of the aircraft utilising the airfield. In addition, we have analysed the mean number of strikes per year and the mean number of birds struck per bird strike. Following a very serious incident involving a Boeing 737-200 which struck a flock of gulls in the mid -1980’s, a new regime of control measures was put in place. Therefore our study permits us to evaluate the effectiveness of this management programme. The results suggest that the most significant impact of control measures is to reduce the number of birds being struck per bird strike

Impact of different unconditional monetary incentives on survey response rates in men with prostate cancer: A 2-arm randomised trial

Background: Men are often viewed as a difficult group to recruit for psychological research, including in psycho-oncology. Whilst research has demonstrated the effectiveness of small monetary incentives for encouraging research participation, little research has examined different large unconditional incentive amounts. Larger unconditional incentives may result in increased participation of men in psychological research. This randomised study within a case–control trial of men diagnosed with early-stage prostate cancer aimed to investigate whether (a) response rates to a 30-min questionnaire completed via mail, online, or phone would vary with different unconditional incentive amounts, and (b) demographics would vary in those who responded within the different incentive groups. Methods: We conducted this randomised study within a case–control cross-sectional study aiming to identify the social-ecological factors influencing treatment discontinuation in prostate cancer patients. A total of 238 participants from the cross-sectional study were randomised to receive one of two unconditional incentives (n = 121 received AUD $10, n = 117 received AUD$20) with the study materials (consent form and survey). Results: Overall, 113 (47 %) responded; n = 61/121 (50.4 %) in the AUD $10 group, and n = 52/117 (44.4$20 group. No evidence of a difference was found in response rates by incentive group (odds ratio 1.27, 95 % CI = 0.76 – 2.12, p = 0.36). Additionally, there were no evident differences in the demographics of the responders vs. non-responders within each incentive group (all p \u3e 0.05). Conclusions: Unlike previous research, we were unable to show that higher monetary incentives were more effective for increasing response rates. An AUD $20 unconditional incentive may be no more effective than a lesser amount for encouraging prostate cancer survivors to participate in research involving long questionnaires. Future research should consider the cost-benefits of providing large unconditional incentives, as non-responses will result in lost resources perhaps better utilised in other engagement strategies

Why do men with prostate cancer discontinue active surveillance for definitive treatment? A mixed methods investigation

Objectives: To explore the personal and/or medical reasons patients on active surveillance (AS) have, or consider having, further definitive treatment for their prostate cancer. Research suggests up to 50% of patients on AS will discontinue within 5 years, though reasons for discontinuation from the patient\u27s perspective is under-explored. Methods: Prostate cancer patients who were or had been on AS for at least 6 months were recruited. A questionnaire assessed reasons for receiving/considering definitive treatment and the extent to which reasons were personal or medical. Clinical information was extracted from a state-level population registry. A subset of participants were interviewed to further explore questionnaire responses. Results: One-hundred and-three individuals completed the survey; 33 were also interviewed. Fifty-four survey participants (52%) had discontinued AS for definitive treatment. Common reasons for discontinuation were evidence of disease progression, doctor recommendation, desire to act, and fear of progression. Many participants who considered or had treatment reported weighing medical and personal factors equally in their decision. Interview participants described strongly considering any amount of disease progression and personal factors such as fear of progression, family concerns, and adverse vicarious experiences when deciding whether to pursue treatment. Conclusion: Both medical and personal factors are considered when deciding whether to discontinue AS. Identifying predictors of discontinuation is essential for informing supportive care services to improve AS management

Association of Maternal Smoking and Alcohol Consumption with Young Adults' Cannabis Use: A Prospective Study

This 2006 study examined 1) whether maternal use of tobacco and consumption of alcohol when a child is 5 and 14 years of age predict cannabis use in young adults, and 2) whether this association is explained by possible confounding or mediating factors. Data were taken from a prospective birth cohort study of mothers and their children in Brisbane, Australia. This study was based on a cohort of 3,176 young adults who participated at the 21-year follow-up of the study and for whom data were available on maternal smoking and alcohol consumption 5 and 14 years after their birth. After controlling for possible confounders, the authors found that maternal smoking at 14 years was associated with frequent use of cannabis in offspring at 21 years, regardless of maternal smoking at 5 years. Children of mothers who drank more than one glass of alcohol at 5 years and continued at 14 years were more likely to use cannabis in early adulthood. The association between maternal substance use and offspring cannabis use was partially mediated by adolescent externalizing behavior and smoking measured at 14 years. Prevention programs that address maternal and adolescent tobacco use and adolescent externalizing behavior should be considered as strategies to reduce cannabis use by young adult

Does implementation matter if comprehension is lacking? A qualitative investigation into perceptions of advance care planning in people with cancer

Purpose: While advance care planning holds promise, uptake is variable and it is unclear how well people engage with or comprehend advance care planning. The objective of this study was to explore how people with cancer comprehended Advance Care Plans and examine how accurately advance care planning documentation represented patient wishes. Methods: This study used a qualitative descriptive design. Data collection comprised interviews and an examination of participants’ existing advance care planning documentation. Participants included those who had any diagnosis of cancer with an advance care plan recorded: Refusal of Treatment Certificate; Statement of Choices; and/or Enduring Power of Attorney (Medical Treatment) at one cancer treatment centre. Results: Fourteen participants were involved in the study. Twelve participants were female (86%). The mean age was 77 (range: 61-91) and participants had completed their advance care planning documentation between 8 and 72 weeks prior to the interview (mean 33 weeks). Three themes were evident from the data: Incomplete advance care planning understanding and confidence; Limited congruence for attitude and documentation; Advance care planning can enable peace of mind. Complete advance care planning understanding was unusual; most participants demonstrated partial comprehension of their own advance care plan, and some indicated very limited understanding. Participants’ attitudes and their written document congruence was limited, but advance care planning was seen as helpful. Conclusions: This study highlighted advance care planning was not a completely accurate representation of patient wishes. There is opportunity to improve how patients comprehend their own advance care planning documentation