Universal Algorithms: Beyond the Simplex

The bulk of universal algorithms in the online convex optimisation literature are variants of the Hedge (exponential weights) algorithm on the simplex. While these algorithms extend to polytope domains by assigning weights to the vertices, this process is computationally unfeasible for many important classes of polytopes where the number $V$ of vertices depends exponentially on the dimension $d$. In this paper we show the Subgradient algorithm is universal, meaning it has $O(\sqrt N)$ regret in the antagonistic setting and $O(1)$ pseudo-regret in the i.i.d setting, with two main advantages over Hedge: (1) The update step is more efficient as the action vectors have length only $d$ rather than $V$; and (2) Subgradient gives better performance if the cost vectors satisfy Euclidean rather than sup-norm bounds. This paper extends the authors' recent results for Subgradient on the simplex. We also prove the same $O(\sqrt N)$ and $O(1)$ bounds when the domain is the unit ball. To the authors' knowledge this is the first instance of these bounds on a domain other than a polytope.Comment: 1 figure, 40 page

A New Framework for the Assessment and Calibration of Medium Range Ensemble Temperature Forecasts

We present a new framework for the assessment and calibration of medium range ensemble temperature forecasts. The method is based on maximising the likelihood of a simple parametric model for the temperature distribution, and leads to some new insights into the predictability of uncertainty.Comment: Submitted to AS

The Iowa Homemaker vol.9, no.2

What the Graduate May Do by Mary Elva Sather, page 1 Art in Flower Arrangement by Ruth Dean, page 2 Here Comes the Bride by Dorothy Anderson, page 3 Grading Market Eggs by Jean Guthrie, page 3 Art and Artists, page 4 4-H Club by Mrs. Edith Barker, page 6 Home Economics Association by Marcia E. Turner, page 8 Mrs. Scott Takes a Vacation by Isabel Leith, page 10 Editorial, page 11 Alumnae News by Vera Caulum, page 1

Data assimilation in slow-fast systems using homogenized climate models

A deterministic multiscale toy model is studied in which a chaotic fast subsystem triggers rare transitions between slow regimes, akin to weather or climate regimes. Using homogenization techniques, a reduced stochastic parametrization model is derived for the slow dynamics. The reliability of this reduced climate model in reproducing the statistics of the slow dynamics of the full deterministic model for finite values of the time scale separation is numerically established. The statistics however is sensitive to uncertainties in the parameters of the stochastic model. It is investigated whether the stochastic climate model can be beneficial as a forecast model in an ensemble data assimilation setting, in particular in the realistic setting when observations are only available for the slow variables. The main result is that reduced stochastic models can indeed improve the analysis skill, when used as forecast models instead of the perfect full deterministic model. The stochastic climate model is far superior at detecting transitions between regimes. The observation intervals for which skill improvement can be obtained are related to the characteristic time scales involved. The reason why stochastic climate models are capable of producing superior skill in an ensemble setting is due to the finite ensemble size; ensembles obtained from the perfect deterministic forecast model lacks sufficient spread even for moderate ensemble sizes. Stochastic climate models provide a natural way to provide sufficient ensemble spread to detect transitions between regimes. This is corroborated with numerical simulations. The conclusion is that stochastic parametrizations are attractive for data assimilation despite their sensitivity to uncertainties in the parameters.Comment: Accepted for publication in Journal of the Atmospheric Science

Wet Paint: Visual Culture in a Changing Britain – A Round Table Debate

Political decisions and debates regarding the interregional and interna- tional partnerships that constitute Great Britain, including those over Scottish Independence, EVEL (English Votes for English Laws) and proposed legislation on an ‘in/out’ referendum on British membership of the European Union, have contributed to, and intensified, the examination of Britain’s institutions, as well as its national emblems and arche- types. In light of such a dynamic situation, Visual Culture in Britain has asked representatives of British universities, the museum sector and research centres to respond to the idea of a changing Britain through the prism of British art and visual culture, using cogent examples wherever possible, and to outline their observations, understandings and positions within this rapidly developing context

Sequential phase II Southwest Oncology Group studies (S0112 and S0301) of daunorubicin and cytarabine by continuous infusion, without and with ciclosporin, in older patients with previously untreated acute myeloid leukaemia

Attempts to overcome multi-drug resistance in acute myeloid leukaemia (AML) have been limited by toxicities. To investigate the effect of reducing peak drug levels, we performed sequential phase II studies using continuous infusion daunorubicin and cytarabine without (AD) and then with ciclosporin (ADC) in older patients with AML. Untreated patients (age 56+ years) received daunorubicin (45 mg/m 2 per day for 3 d) and cytarabine (200 mg/m 2 per day for 7 d), both by continuous infusion, without (S0112, 60 patients) and then with (S0301, 50 patients) the addition of ciclosporin. Complete response (CR) rates were 38% on S0112 and 44% on S0301. Fatal induction toxicities occurred in 17% and 12% respectively, arising primarily from infection and haemorrhage. Median overall and relapse-free survival was 7 and 8 months for AD respectively, and 6 and 14 months for ADC. Patients with phenotypic or functional P-glycoprotein had somewhat higher CR rates with ADC than AD, although confidence intervals overlapped. In these sequential trials, continuous infusion AD produced CR rates comparable to those with bolus daunorubicin. The addition of ciclosporin did not cause undue toxicities, produced a similar CR rate, and possibly improved relapse-free survival. Further correlate analyses did not identify a subpopulation specifically benefitting from the addition of ciclosporin.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78683/1/j.1365-2141.2009.07919.x.pd

Topographic stress and rock fracture: a two-dimensional numerical model for arbitrary topography and preliminary comparison with borehole observations

Theoretical calculations indicate that elastic stresses induced by surface topography may be large enough in some landscapes to fracture rocks, which in turn could influence slope stability, erosion rates, and bedrock hydrologic properties. These calculations typically have involved idealized topographic profiles, with few direct comparisons of predicted topographic stresses and observed fractures at specific field sites. We use a numerical model to calculate the stresses induced by measured topographic profiles and compare the calculated stress field with fractures observed in shallow boreholes. The model uses a boundary element method to calculate the stress distribution beneath an arbitrary topographic profile in the presence of ambient tectonic stress. When applied to a topographic profile across the Susquehanna Shale Hills Critical Zone Observatory in central Pennsylvania, the model predicts where shear fractures would occur based on a Mohr–Coulomb criterion, with considerable differences in profiles of stresses with depth beneath ridgetops and valley floors. We calculate the minimum cohesion required to prevent shear failure, C[subscript min], as a proxy for the potential for fracturing or reactivation of existing fractures. We compare depth profiles of C[subscript min] with structural analyses of image logs from four boreholes located on the valley floor, and find that fracture abundance declines sharply with depth in the uppermost 15 m of the bedrock, consistent with the modeled profile of C[subscript min]. In contrast, C[subscript min] increases with depth at comparable depths below ridgetops, suggesting that ridgetop fracture abundance patterns may differ if topographic stresses are indeed important. Thus, the present results are consistent with the hypothesis that topography can influence subsurface rock fracture patterns and provide a basis for further observational tests.United States. Army Research Office (Award W911NF-14-1-0037)United States. Dept. of Energy (Award DE-FG01-97ER14760

Effect of physical activity, social support, and skills training on late-life emotional health: a systematic literature review and implications for public health research

Purpose: Given that emotional health is a critical component of healthy aging, we undertook a systematic literature review to assess whether current interventions can positively affect older adults’ emotional health. Methods: A national panel of health services and mental health researchers guided the review. Eligibility criteria included community-dwelling older adult (aged ≥ 50 years) samples, reproducible interventions, and emotional health outcomes, which included multiple domains and both positive (well-being) and illness-related (anxiety) dimensions. This review focused on three types of interventions – physical activity, social support, and skills training – given their public health significance and large number of studies identified. Panel members evaluated the strength of evidence (quality and effectiveness). Results: In all, 292 articles met inclusion criteria. These included 83 exercise/physical activity, 25 social support, and 40 skills training interventions. For evidence rating, these 148 interventions were categorized into 64 pairings by intervention type and emotional health outcome, e.g., strength training targeting loneliness or social support to address mood. 83% of these pairings were rated at least fair quality. Expert panelists found sufficient evidence of effectiveness only for skills training interventions with health outcomes of decreasing anxiety and improving quality of life and self-efficacy. Due to limitations in reviewed studies, many intervention–outcome pairings yielded insufficient evidence. Conclusion: Skills training interventions improved several aspects of emotional health in community-dwelling older adults, while the effects for other outcomes and interventions lacked clear evidence. We discuss the implications and challenges in moving forward in this important area

The Healthy Aging Research Network: Resources for Building Capacity for Public Health and Aging Practice

There is an urgent need to translate science into practice and help enhance the capacity of professionals to deliver evidence-based programming. We describe contributions of the Healthy Aging Research Network in building professional capacity through online modules, issue briefs, monographs, and tools focused on health promotion practice, physical activity, mental health, and environment and policy. We also describe practice partnerships and research activities that helped inform product development and ways these products have been incorporated into real-world practice to illustrate possibilities for future applications. Our work aims to bridge the research-to-practice gap to meet the demands of an aging population