Meta-descent for Online, Continual Prediction

This paper investigates different vector step-size adaptation approaches for non-stationary online, continual prediction problems. Vanilla stochastic gradient descent can be considerably improved by scaling the update with a vector of appropriately chosen step-sizes. Many methods, including AdaGrad, RMSProp, and AMSGrad, keep statistics about the learning process to approximate a second order update---a vector approximation of the inverse Hessian. Another family of approaches use meta-gradient descent to adapt the step-size parameters to minimize prediction error. These meta-descent strategies are promising for non-stationary problems, but have not been as extensively explored as quasi-second order methods. We first derive a general, incremental meta-descent algorithm, called AdaGain, designed to be applicable to a much broader range of algorithms, including those with semi-gradient updates or even those with accelerations, such as RMSProp. We provide an empirical comparison of methods from both families. We conclude that methods from both families can perform well, but in non-stationary prediction problems the meta-descent methods exhibit advantages. Our method is particularly robust across several prediction problems, and is competitive with the state-of-the-art method on a large-scale, time-series prediction problem on real data from a mobile robot.Comment: AAAI Conference on Artificial Intelligence 2019. v2: Correction to Baird's counterexample. A bug in the code lead to results being reported for AMSGrad in this experiment, when they were actually results for Ada

Efficiency and adaptability of the benthic methane filter at Quepos Slide cold seeps, offshore Costa Rica

Large amounts of methane are delivered by fluids through the erosive forearc of the convergent margin offshore Costa Rica and lead to the formation of cold seeps at the sediment surface. Besides mud extrusion, numerous cold seeps are created by landslides induced by seamount subduction or fluid migration along major faults. Most of the dissolved methane reaching the seafloor at cold seeps is oxidized within the benthic microbial methane filter by anaerobic oxidation of methane (AOM). Measurements of AOM and sulfate reduction as well as numerical modeling of porewater profiles revealed a highly active and efficient benthic methane filter at Quepos Slide site; a landslide on the continental slope between the Nicoya and Osa Peninsula. Integrated areal rates of AOM ranged from 12.9 ± 6.0 to 45.2 ± 11.5 mmol m-2 d-1, with only 1 to 2.5% of the upward methane flux being released into the water column. Additionally, two parallel sediment cores from Quepos Slide were used for in vitro experiments in a recently developed Sediment-F low-Through (SLOT) system to simulate an increased fluid and methane flux from the bottom of the sediment core. The benthic methane filter revealed a high adaptability whereby the methane oxidation efficiency responded to the increased fluid flow within 150–170 days. To our knowledge, this study provides the first estimation of the natural biogeochemical response of seep sediments to changes in fluid flow

Phase II Study of Paclitaxel in Patients With Soft Tissue Sarcomas

Purpose. Patients with soft tissue sarcoma (STS) who have previously received standard chemotherapy including adriamycin (doxorubicin), ifosfamide, cyclophosphamide and DTIC (dacarbazine) have very limited therapeutic options. It is important to identify new drugs with some activity in this disease and we therefore undertook this trial to determine the antitumor activity of paclitaxel (Taxol)

The feasibility and effectiveness of a web-based personalised feedback and social norms alcohol intervention in UK university students: A randomised control trial

OBJECTIVE Alcohol misuse amongst University students is a serious concern, and research has started to investigate the feasibility of using e-health interventions. This study aimed to establish the effectiveness of an electronic web-based personalised feedback intervention through the use of a randomised control trial (RCT). METHODS 506 participants were stratified by gender, age group, year of study, self-reported weekly consumption of alcohol and randomly assigned to either a control or intervention condition. Intervention participants received electronic personalised feedback and social norms information on their drinking behaviour which they could access by logging onto the website at any time during the 12-week period. CAGE score, average number of alcoholic drinks consumed per drinking occasion, and alcohol consumption over the last week were collected from participants at pre- and post-survey. RESULTS A significant difference in pre- to post-survey mean difference of alcohol consumed per occasion was found, with those in the intervention condition displaying a larger mean decrease when compared to controls. No intervention effect was found for units of alcohol consumed per week or for CAGE scores. Sixty-three percent of intervention participants agreed that the feedback provided was useful. Those intervention participants who were above the CAGE cut off were more likely to report that the website would make them think more about the amount they drank. CONCLUSIONS Delivering an electronic personalised feedback intervention to students via the World Wide Web is a feasible and potentially effective method of reducing student alcohol intake. Further research is needed to replicate this outcome, evaluate maintenance of any changes, and investigate the process of interaction with web-based interventions

The effectiveness of web-based interventions designed to decrease alcohol consumption – a systematic review

OBJECTIVE To review the published literature on the effectiveness of web-based interventions designed to decrease consumption of alcohol and/or prevent alcohol abuse. METHOD Relevant articles published up to, and including, May 2006 were identified through electronic searches of Medline, PsycInfo, Embase, Cochrane Library, ASSIA, Web of Science and Science Direct. Reference lists of all articles identified for inclusion were checked for articles of relevance. An article was included if its stated or implied purpose was to evaluate a web-based intervention designed to decrease consumption of alcohol and/or to prevent alcohol abuse. Studies were reliably selected and quality-assessed, and data were independently extracted and interpreted by two authors. RESULTS Initial searches identified 191 articles of which 10 were eligible for inclusion. Of these, five provided a process evaluation only, with the remaining five providing some pre-to post-intervention measure of effectiveness. In general the percentage quality criteria met was relatively low and only one of the 10 articles selected was a randomized control trial. CONCLUSION The current review provides inconsistent evidence on the effectiveness of eIectronic screening and brief intervention (eSBI) for alcohol use. Process research suggests that web-based interventions are generally well received. However further controlled trials are needed to fully investigate their efficacy, to determine which elements are keys to outcome and to understand if different elements are required in order to engage low- and high-risk drinkers

Microbes, macrofauna, and methane: a novel seep community fueled by aerobic methanotrophy

During the discovery and description of seven New Zealand methane seep sites, an infaunal assemblage dominated by ampharetid polychaetes was found in association with high seabed methane emission. This ampharetid-bed assemblage had a mean density of 57,000 ± 7800 macrofaunal individuals m−2 and a maximum wet biomass of 274 g m−2, both being among the greatest recorded from deep-sea methane seeps. We investigated these questions: Does the species assemblage present within these ampharetid beds form a distinct seep community on the New Zealand margin? and What type of chemoautotrophic microbes fuel this heterotrophic community? Unlike the other macro-infaunal assemblages, the ampharetid-bed assemblage composition was homogeneous, independent of location. Based on a mixing model of species-specific mass and isotopic composition, combined with published respiration measurements, we estimated that this community consumes 29–90 mmol C m−2 d−1 of methane-fueled biomass; this is > 290 times the carbon fixed by anaerobic methane oxidizers in these ampharetid beds. A fatty acid biomarker approach supported the finding that this community, unlike those previously known, consumes primarily aerobic methanotrophic bacteria. Due to the novel microbial fueling and high methane flux rates, New Zealand's ampharetid beds provide a model system to study the influence of metazoan grazing on microbially mediated biogeochemical cycles, including those that involve greenhouse gas emission

Simulating and Quantifying Multiple Natural Subsea CO2 Seeps at Panarea Island (Aeolian Islands, Italy) as a Proxy for Potential Leakage from Subseabed Carbon Storage Sites

Carbon dioxide (CO2) capture and storage (CCS) has been discussed as a potentially significant mitigation option for the ongoing climate warming. Natural CO2 release sites serve as natural laboratories to study subsea CO2 leakage in order to identify suitable analytical methods and numerical models to develop best-practice procedures for the monitoring of subseabed storage sites. We present a new model of bubble (plume) dynamics, advection-dispersion of dissolved CO2, and carbonate chemistry. The focus is on a medium-sized CO2 release from 294 identified small point sources around Panarea Island (South-East Tyrrhenian Sea, Aeolian Islands, Italy) in water depths of about 40–50 m. This study evaluates how multiple CO2 seep sites generate a temporally variable plume of dissolved CO2. The model also allows the overall flow rate of CO2 to be estimated based on field measurements of pH. Simulations indicate a release of ∼6900 t y–1 of CO2 for the investigated area and highlight an important role of seeps located at >20 m water depth in the carbon budget of the Panarea offshore gas release system. This new transport-reaction model provides a framework for understanding potential future leaks from CO2 storage sites

The chemistry and kinematics of two molecular clouds near Sagittarius A

We have analysed the chemical and kinematic properties of the 20 and 50 km s−1 molecular clouds in the Central Molecular Zone of the Milky Way Galaxy, as well as those of the molecular ridge bridging these two clouds. Our work has utilized 37 molecular transitions in the 0.65, 3 and 7-mm wavebands, from the Mopra and NANTEN2 telescopes. The 0.65-mm NANTEN2 data highlights a dense condensation of emission within the western part of the 20 km s−1 cloud, visible in only four other transitions, which are 3-mm H13CN (1–0), H13CO+ (1–0), HNC (1–0) and N2H+ (1–0), suggesting that the condensation is moderately optically thick and cold. We find that while the relative chemical abundances between both clouds are alike in many transitions, suggesting little variation in the chemistry between both clouds; the 20 km s−1, cold cloud is brighter than the 50 km s−1 cloud in shock and high density tracers. The spatial distribution of enhanced emission is widespread in the 20 km s−1 cloud, as shown via line ratio maps. The position velocity diagrams across both clouds indicate that the gas is well mixed. We show that the molecular ridge is most likely part of the 20 km s−1 cloud and that both of them may possibly extend to include the 50 km s−1 cloud, as part of one larger cloud. Furthermore, we expect that the 20 km s−1 cloud is being tidally sheared as a result of the gravitational potential from Sgr A*

Thermoregulatory ability and mechanism do not differ consistently between neotropical and temperate butterflies

Climate change is a major threat to species worldwide, yet it remains uncertain whether tropical or temperate species are more vulnerable to changing temperatures. To further our understanding of this, we used a standardised field protocol to (1) study the buffering ability (ability to regulate body temperature relative to surrounding air temperature) of neotropical (Panama) and temperate (the United Kingdom, Czech Republic and Austria) butterflies at the assemblage and family level, (2) determine if any differences in buffering ability were driven by morphological characteristics and (3) used ecologically relevant temperature measurements to investigate how butterflies use microclimates and behaviour to thermoregulate. We hypothesised that temperate butterflies would be better at buffering than neotropical butterflies as temperate species naturally experience a wider range of temperatures than their tropical counterparts. Contrary to our hypothesis, at the assemblage level, neotropical species (especially Nymphalidae) were better at buffering than temperate species, driven primarily by neotropical individuals cooling themselves more at higher air temperatures. Morphology was the main driver of differences in buffering ability between neotropical and temperate species as opposed to the thermal environment butterflies experienced. Temperate butterflies used postural thermoregulation to raise their body temperature more than neotropical butterflies, probably as an adaptation to temperate climates, but the selection of microclimates did not differ between regions. Our findings demonstrate that butterfly species have unique thermoregulatory strategies driven by behaviour and morphology, and that neotropical species are not likely to be more inherently vulnerable to warming than temperate species

Impaired Cardiac and Skeletal Muscle Energetics Following Anthracycline Therapy for Breast Cancer

Acknowledgments The fellow (Dr Gamble) recruited participants, scheduled, coordinated, and performed all clinical imaging investigations, patients skeletal muscle biopsies and venesection, conducted mitochondrial copy number analysis of muscle biopsies under supervision, analyzed all data, performed statistical analyses under supervision, and drafted this article. H. Khan and A. Rudd helped with the investigations and reviewed and contributed to this article. S. Baliga provided the healthy volunteer skeletal muscle biopsies. Dr Ross designed and developed the protocol for cardiac and skeletal muscle spectroscopy. L. Cheyne supervised muscle biopsy analyses. Drs Unger and Linke performed the skeletal muscle transmission electron microscopy and immunofluorescence confocal microscopy investigations. Dr Horgan is the study statistician. Drs Urquhart, Masannat, Elsberger, Fuller, Mustafa, and Sharma identified and recruited participants and reviewed and contributed to this article. Drs Hannah, Sharma, and Saunders contributed to the design of the study. D. Dawson (PI) designed the study, obtained funding (together with Drs Sharma and Masannat) and regulatory approvals, supervised the unfolding of the study, its analyses and revised the article drafts. Sources of Funding Tenovus Scotland G18.01, D. Dawson and Dr Sharma, Friends of Anchor 2019, Grampian National Health Service-Endowments (Drs Sharma and Masannat), British Health Foundation PG/18/35/33786 to D. Dawson funded DG salary and BHF FS/RTF/20/30009 to D. Dawson funded AR salary.Peer reviewedPublisher PD