24,844 research outputs found

    Dimension-independent Harnack inequalities for subordinated semigroups

    Full text link
    Dimension-independent Harnack inequalities are derived for a class of subordinate semigroups. In particular, for a diffusion satisfying the Bakry-Emery curvature condition, the subordinate semigroup with power α\alpha satisfies a dimension-free Harnack inequality provided α∈(1/2,1)\alpha \in(1/2, 1), and it satisfies the log-Harnack inequality for all α∈(0,1).\alpha \in (0,1). Some infinite-dimensional examples are also presented

    A comparison of neuroimaging abnormalities in multiple sclerosis, major depression and chronic fatigue syndrome (Myalgic Encephalomyelitis): is there a common cause?

    Get PDF
    There is copious evidence of abnormalities in resting-state functional network connectivity states, grey and white matter pathology and impaired cerebral perfusion in patients afforded a diagnosis of multiple sclerosis, major depression or chronic fatigue syndrome (CFS) (myalgic encephalomyelitis). Systemic inflammation may well be a major element explaining such findings. Inter-patient and inter-illness variations in neuroimaging findings may arise at least in part from regional genetic, epigenetic and environmental variations in the functions of microglia and astrocytes. Regional differences in neuronal resistance to oxidative and inflammatory insults and in the performance of antioxidant defences in the central nervous system may also play a role. Importantly, replicated experimental findings suggest that the use of high-resolution SPECT imaging may have the capacity to differentiate patients afforded a diagnosis of CFS from those with a diagnosis of depression. Further research involving this form of neuroimaging appears warranted in an attempt to overcome the problem of aetiologically heterogeneous cohorts which probably explain conflicting findings produced by investigative teams active in this field. However, the ionising radiation and relative lack of sensitivity involved probably preclude its use as a routine diagnostic tool

    Color-coordinate system from a 13th-century account of rainbows.

    Get PDF
    We present a new analysis of Robert Grosseteste’s account of color in his treatise De iride (On the Rainbow), dating from the early 13th century. The work explores color within the 3D framework set out in Grosseteste’s De colore [see J. Opt. Soc. Am. A 29, A346 (2012)], but now links the axes of variation to observable properties of rainbows. We combine a modern understanding of the physics of rainbows and of human color perception to resolve the linguistic ambiguities of the medieval text and to interpret Grosseteste’s key terms

    Dynamic treatment for proximal phalangeal fracture of the hand

    Get PDF
    PURPOSE: To assess a protected mobilisation programme (dynamic treatment) for proximal phalangeal fracture of the hand, irrespective of the geometry. METHODS: Clinical and radiological results of 32 consecutive patients with proximal phalangeal fracture of the hand treated from January 2001 to February 2007 were evaluated. Our supervised rehabilitation programme was strictly followed to gain full range of movement of the proximal interphalangeal joint and to prevent the development of an extension lag contracture. Patients were followed up for a mean period of 15 (range, 13-16) months. Results were evaluated using the Belsky classification. RESULTS: The results were excellent in 72% of the patients, good in 22%, and poor in 6%. Some patients defaulted follow-up, which made long-term assessment difficult. The poor results may have been related to patient non-compliance or default from rehabilitation. Many good results upgraded to excellent following further rehabilitation. CONCLUSION: Skeletal stability, not rigidity, is necessary for functional movements of the hand. Proximal phalangeal fractures can be effectively treated by closed methods, using the stabilising effect of soft tissues (zancolli complex-metacarpophalangeal retention apparatus) and external devices (metacarpophalangeal block splint), thus enabling bone healing and movement recovery at the same time.published_or_final_versio

    Characterization and utilization of fermented cassava flour in breadmaking and placali preparation

    Get PDF
    Freshly harvested cassava roots from yace cultivar were collected in five regions of Ivory Coast and characterized. These roots were processed into fermented flour. The physicochemical characteristics of flours were evaluated following standard methods and, the ability to be valorised in placali preparation and breadmaking were assessed by sensory analysis of products obtained. Both roots and fermented flours were energizing foods. Moisture (6.09-10.49%), protein (1.12-1.57%), ash (0.87-1.39%), fat (0.20-0.51%), total sugars (1.43-1.80%) and cyanide contents (3.33-10.00 mg HCN/kg) of fermented flours were low, while starch (72.79-84.23%), total carbohydrate (93.67-96.45%) and energy (384.53-393.50 kcal/100 g) contents were high. Minerals like phosphorus (78.00-133.33 mg/100 g), calcium (52.66-142.92 mg/100 g), magnesium (27.77- 69.26 mg/100 g), iron (2.5-8.20 mg/100 g) and zinc (1.56-6.98 mg/100 g) were available. The sensory evaluation test indicated a significant difference (p<0.05) between the placali samples in terms of visual appearance, odour, taste, texture and overall appreciation. It is a clear indication that reconstitution proportion (flour to water ratio) affects all the hedonic appreciations assessed. Placali prepared from fermented cassava flour were appreciated when reconstitution proportion was within 1:3.5 and 1:3. Composite breads of 85% wheat and 15% cassava fermented flour were accepted by a sensory evaluation panellist. Fermented flour has been successfully used in breadmaking and placali preparation. It is a means of diversifying cassava utilization form.Keywords: Gelatinized food, yace cultivar, sensory evaluation, composite flour, bread

    How self-organization can guide evolution

    Get PDF
    Self-organization and natural selection are fundamental forces that shape the natural world. Substantial progress in understanding how these forces interact has been made through the study of abstract models. Further progress may be made by identifying a model system in which the interaction between self-organization and selection can be investigated empirically. To this end, we investigate how the self-organizing thermoregulatory huddling behaviours displayed by many species of mammals might influence natural selection of the genetic components of metabolism. By applying a simple evolutionary algorithm to a wellestablished model of the interactions between environmental, morphological, physiological and behavioural components of thermoregulation, we arrive at a clear, but counterintuitive, prediction: rodents that are able to huddle together in cold environments should evolve a lower thermal conductance at a faster rate than animals reared in isolation. The model therefore explains how evolution can be accelerated as a consequence of relaxed selection, and it predicts how the effect may be exaggerated by an increase in the litter size, i.e. by an increase in the capacity to use huddling behaviours for thermoregulation. Confirmation of these predictions in future experiments with rodents would constitute strong evidence of a mechanism by which self-organization can guide natural selection

    ForestHash: Semantic Hashing With Shallow Random Forests and Tiny Convolutional Networks

    Full text link
    Hash codes are efficient data representations for coping with the ever growing amounts of data. In this paper, we introduce a random forest semantic hashing scheme that embeds tiny convolutional neural networks (CNN) into shallow random forests, with near-optimal information-theoretic code aggregation among trees. We start with a simple hashing scheme, where random trees in a forest act as hashing functions by setting `1' for the visited tree leaf, and `0' for the rest. We show that traditional random forests fail to generate hashes that preserve the underlying similarity between the trees, rendering the random forests approach to hashing challenging. To address this, we propose to first randomly group arriving classes at each tree split node into two groups, obtaining a significantly simplified two-class classification problem, which can be handled using a light-weight CNN weak learner. Such random class grouping scheme enables code uniqueness by enforcing each class to share its code with different classes in different trees. A non-conventional low-rank loss is further adopted for the CNN weak learners to encourage code consistency by minimizing intra-class variations and maximizing inter-class distance for the two random class groups. Finally, we introduce an information-theoretic approach for aggregating codes of individual trees into a single hash code, producing a near-optimal unique hash for each class. The proposed approach significantly outperforms state-of-the-art hashing methods for image retrieval tasks on large-scale public datasets, while performing at the level of other state-of-the-art image classification techniques while utilizing a more compact and efficient scalable representation. This work proposes a principled and robust procedure to train and deploy in parallel an ensemble of light-weight CNNs, instead of simply going deeper.Comment: Accepted to ECCV 201

    Noncommutative geometry and stochastic processes

    Full text link
    The recent analysis on noncommutative geometry, showing quantization of the volume for the Riemannian manifold entering the geometry, can support a view of quantum mechanics as arising by a stochastic process on it. A class of stochastic processes can be devised, arising as fractional powers of an ordinary Wiener process, that reproduce in a proper way a stochastic process on a noncommutative geometry. These processes are characterized by producing complex values and so, the corresponding Fokker-Planck equation resembles the Schroedinger equation. Indeed, by a direct numerical check, one can recover the kernel of the Schroedinger equation starting by an ordinary Brownian motion. This class of stochastic processes needs a Clifford algebra to exist. In four dimensions, the full set of Dirac matrices is needed and the corresponding stochastic process in a noncommutative geometry is easily recovered as is the Dirac equation in the Klein-Gordon form being it the Fokker--Planck equation of the process.Comment: 16 pages, 2 figures. Updated a reference. A version of this paper will appear in the proceedings of GSI2017, Geometric Science of Information, November 7th to 9th, Paris (France

    Assessment of Maize Stem Borer Damage on Hybrid Maize Varieties in Chitwan, Nepal

    Full text link
    Maize is the second most important cereal crop in Nepal. However, national figure of grain production still remains below than the world's average grain production per unit area. Thus, this experiment was designed to determine the suitable time of maize planting, and to assess the peak period of one of the major insects, maize stem borer, in Chitwan condition. The results showed that plant damage percentage as per the maize planting month varies significantly, and the average plant damage percentage by stem borer was up to 18.11%. Length of the feeding tunnel in maize stem was significantly higher in January than July. In case of exit holes made by borer counted more than four holes per plant that were planted in the month of January. All in all, except the tunnel length measurement per plant, we observed similar pattern in other borer damage parameters such as exit whole counts and plant damage percentage within the tested varieties. Stem borer damage was not significantly affect on grain yield.Journal of Maize Research and Development (2015) 1(1):53-63DOI: http://dx.doi.org/10.5281/zenodo.3429
    • …
    corecore