Machine learning in geosciences and remote sensing

Learning incorporates a broad range of complex procedures. Machine learning (ML) is a subdivision of artificial intelligence based on the biological learning process. The ML approach deals with the design of algorithms to learn from machine readable data. ML covers main domains such as data mining, difficult-to-program applications, and software applications. It is a collection of a variety of algorithms (e.g. neural networks, support vector machines, self-organizing map, decision trees, random forests, case-based reasoning, genetic programming, etc.) that can provide multivariate, nonlinear, nonparametric regression or classification. The modeling capabilities of the ML-based methods have resulted in their extensive applications in science and engineering. Herein, the role of ML as an effective approach for solving problems in geosciences and remote sensing will be highlighted. The unique features of some of the ML techniques will be outlined with a specific attention to genetic programming paradigm. Furthermore, nonparametric regression and classification illustrative examples are presented to demonstrate the efficiency of ML for tackling the geosciences and remote sensing problems

The Ross Sea in a sea of change

The Ross Sea, the most productive region in the Antarctic, reaches farther south than any body of water in the world. While its food web is relatively intact, its oceanography, biogeochemistry, and sea ice coverage have been changing dramatically, and likely will continue to do so in the future. Sea ice cover and persistence have been increasing, in contrast to the Amundsen-Bellingshausen sector, which has resulted in reduced open water duration for its biota. Models predict that as the ozone hole recovers, ice cover will begin to diminish. Currents on the continental shelf will likely change in the coming century, with a projected intensification of flow leading to altered deep ocean ventilation. Such changes in ice and circulation will lead to altered plankton distributions and composition, but it is difficult at present to predict the nature of these changes. Iron and irradiance play central roles in regulating phytoplankton production in the Ross Sea, but the impacts of oceanographic changes on the biogeochemistry of iron are unclear. Unlike other Southern Ocean regions, where continental shelves are very narrow and Antarctic krill dominates the herbivorous fauna, the broad shelf of the Ross Sea is dominated by crystal krill and silverfish, which are the major prey items for higher trophic levels. At present, the Ross Sea is considered to be one of the most species-rich areas of the Southern Ocean and a biodiversity hotspot due to its heterogeneous habitats. Despite being among the best-studied regions in the entire Southern Ocean, accurate predictions of the impacts of climate change on the oceanography and ecology of the Ross Sea remain fraught with uncertainty

Enhanced flight performance by genetic manipulation of wing shape in Drosophila

Insect wing shapes are remarkably diverse and the combination of shape and kinematics determines both aerial capabilities and power requirements. However, the contribution of any specific morphological feature to performance is not known. Using targeted RNA interference to modify wing shape far beyond the natural variation found within the population of a single species, we show a direct effect on flight performance that can be explained by physical modelling of the novel wing geometry. Our data show that altering the expression of a single gene can significantly enhance aerial agility and that the Drosophila wing shape is not, therefore, optimized for certain flight performance characteristics that are known to be important. Our technique points in a new direction for experiments on the evolution of performance specialities in animals

Premenopausal endogenous oestrogen levels and breast cancer risk: a meta-analysis.

BACKGROUND: Many of the established risk factors for breast cancer implicate circulating hormone levels in the aetiology of the disease. Increased levels of postmenopausal endogenous oestradiol (E2) have been found to increase the risk of breast cancer, but no such association has been confirmed in premenopausal women. We carried out a meta-analysis to summarise the available evidence in women before the menopause. METHODS: We identified seven prospective studies of premenopausal endogenous E2 and breast cancer risk, including 693 breast cancer cases. From each study we extracted odds ratios of breast cancer between quantiles of endogenous E2, or for unit or s.d. increases in (log transformed) E2, or (where odds ratios were unavailable) summary statistics for the distributions of E2 in breast cancer cases and unaffected controls. Estimates for a doubling of endogenous E2 were obtained from these extracted estimates, and random-effect meta-analysis was used to obtain a pooled estimate across the studies. RESULTS: Overall, we found weak evidence of a positive association between circulating E2 levels and the risk of breast cancer, with a doubling of E2 associated with an odds ratio of 1.10 (95% CI: 0.96, 1.27). CONCLUSION: Our findings are consistent with the hypothesis of a positive association between premenopausal endogenous E2 and breast cancer risk

Opportunities and barriers in paediatric pulse oximetry for pneumonia in low-resource clinical settings: a qualitative evaluation from Malawi and Bangladesh

OBJECTIVE: To gain an understanding of what challenges pulse oximetry for paediatric pneumonia management poses, how it has changed service provision and what would improve this device for use across paediatric clinical settings in low-income countries. DESIGN: Focus group discussions (FGDs), with purposive sampling and thematic analysis using a framework approach. SETTING: Community, front-line outpatient, and hospital outpatient and inpatient settings in Malawi and Bangladesh, which provide paediatric pneumonia care. PARTICIPANTS: Healthcare providers (HCPs) from Malawi and Bangladesh who had received training in pulse oximetry and had been using oximeters in routine paediatric care, including community healthcare workers, non-physician clinicians or medical assistants, and hospital-based nurses and doctors. RESULTS: We conducted six FGDs, with 23 participants from Bangladesh and 26 from Malawi. We identified five emergent themes: trust, value, user-related experience, sustainability and design. HCPs discussed the confidence gained through the use of oximeters, resulting in improved trust from caregivers and valuing the device, although there were conflicts between the weight given to clinical judgement versus oximeter results. HCPs reported the ease of using oximeters, but identified movement and physically smaller children as measurement challenges. Challenges in sustainability related to battery durability and replacement parts, however many HCPs had used the same device longer than 4 years, demonstrating robustness within these settings. Desirable features included back-up power banks and integrated respiratory rate and thermometer capability. CONCLUSIONS: Pulse oximetry was generally deemed valuable by HCPs for use as a spot-check device in a range of paediatric low-income clinical settings. Areas highlighted as challenges by HCPs, and therefore opportunities for redesign, included battery charging and durability, probe fit and sensitivity in paediatric populations. TRIAL REGISTRATION NUMBER: NCT02941237

Health trainer-led motivational intervention plus usual care for people under community supervision compared with usual care alone: a study protocol for a parallel-group pilot randomised controlled trial (STRENGTHEN).

INTRODUCTION: People with experience of the criminal justice system typically have worse physical and mental health, lower levels of mental well-being and have less healthy lifestyles than the general population. Health trainers have worked with offenders in the community to provide support for lifestyle change, enhance mental well-being and signpost to appropriate services. There has been no rigorous evaluation of the effectiveness and cost-effectiveness of providing such community support. This study aims to determine the feasibility and acceptability of conducting a randomised trial and delivering a health trainer intervention to people receiving community supervision in the UK. METHODS AND ANALYSIS: A multicentre, parallel, two-group randomised controlled trial recruiting 120 participants with 1:1 individual allocation to receive support from a health trainer and usual care or usual care alone, with mixed methods process evaluation. Participants receive community supervision from an offender manager in either a Community Rehabilitation Company or the National Probation Service. If they have served a custodial sentence, then they have to have been released for at least 2 months. The supervision period must have at least 7 months left at recruitment. Participants are interested in receiving support to change diet, physical activity, alcohol use and smoking and/or improve mental well-being. The primary outcome is mental well-being with secondary outcomes related to smoking, physical activity, alcohol consumption and diet. The primary outcome will inform sample size calculations for a definitive trial. ETHICS AND DISSEMINATION: The study has been approved by the Health and Care Research Wales Ethics Committee (REC reference 16/WA/0171). Dissemination will include publication of the intervention development process and findings for the stated outcomes, parallel process evaluation and economic evaluation in peer-reviewed journals. Results will also be disseminated to stakeholders and trial participants. TRIAL REGISTRATION NUMBERS: ISRCTN80475744; Pre-results

Case Report The Management of Gas-Filled Eyes in the Emergency Department

Background. Intraocular gas bubbles are commonly used in retinal surgery. There are specific management guidelines that need to be followed to ensure surgical success, and there are also unique ophthalmic and systemic complications that can occur in such patients. Objective. To educate emergency department personnel about important issues in the management of patients who have a gas-filled eye following retinal surgery. Case Report. A patient with a gas-filled eye developed several complications including pain, severe vision loss, high-grade atrioventricular (AV) block, and pneumocephalus. Conclusion. Awareness of potential problems that may arise in patients with gas-filled eyes who present to the emergency department may help minimize morbidity for such patients

Comparative prebiotic activity of mixtures of cereal grain polysaccharides

The main components of the non-starch polysaccharide (NSP) fraction of wheat flour are arabinoxylan (AX) and β-glucan. These are also present in other cereal grains, but their proportions vary with AX being the major component in wheat and rye and β-glucan in barley and oats. Therefore, it was hypothesised that these NSPs could act synergistically when fermented in vitro at the ratios present in the major foods consumed, resulting in increased prebiotic activity. AX and β-glucan were therefore tested in in vitro fermentation studies to assess their prebiotic activity when used individually and/or in different ratios. Short-chain fatty-acids (SCFAs) produced from in vitro fermentation were measured using HPLC and bacterial populations were measured using flow cytometry with fluorescence in situ hybridisation (Flow-FISH). Fermentation of AX alone resulted in a significant bifidogenic activity and increased concentrations of SCFAs, mainly acetate, after 8-24 h of fermentation, however β-glucan alone did not show prebiotic activity. The greatest prebiotic activity, based on concentration of total SCFAs and increases in total bacteria as well as beneficial Bifidobacterium and Clostridium coccoides/Eubacterium groups, was observed when AX and β-glucan were combined at a 3:1 ratio, which corresponds to their ratios in wheat flour which is major source of cereal fibre in the diet. This indicates that the population of bacteria in the human GI tract may be modulated by the composition of the fibre in the diet, to maximise the prebiotic potential