697 research outputs found

    Dynamic sampling schemes for optimal noise learning under multiple nonsmooth constraints

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    We consider the bilevel optimisation approach proposed by De Los Reyes, Sch\"onlieb (2013) for learning the optimal parameters in a Total Variation (TV) denoising model featuring for multiple noise distributions. In applications, the use of databases (dictionaries) allows an accurate estimation of the parameters, but reflects in high computational costs due to the size of the databases and to the nonsmooth nature of the PDE constraints. To overcome this computational barrier we propose an optimisation algorithm that by sampling dynamically from the set of constraints and using a quasi-Newton method, solves the problem accurately and in an efficient way

    Hydrolyzed Feather Meal as a Protein Supplement for Steer Calves Fed Corn Silage

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    Hydrolyzed feather meal (HFM) was evaluated for soybean meal replacement value in corn silage diets fed t o steer calves. One hundred ninety-two steers (692 lb) were fed corn silage diets formulated to contain 11.5% crude protein. Hydrolyzed feather meal was substituted for soybean meal at levels providing 0, 25, 50 or 75% of the supplemental protein. Overall performance for the 98-day feeding trial was as follows: 2.10 lb average daily gain; 17.91 lb/day dry matter (DM) intake and 8.58 DM/gain. Protein supplements had no effect on performance, indicating that cost per unit protein is the primary consideration when formulating supplements containing HFM for growing calves fed high quality corn silage

    An efficient algorithm for numerical computations of continuous densities of states

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    In Wang-Landau type algorithms, Monte-Carlo updates are performed with respect to the density of states, which is iteratively refined during simulations. The partition function and thermodynamic observables are then obtained by standard integration. In this work, our recently introduced method in this class (the LLR approach) is analysed and further developed. Our approach is a histogram free method particularly suited for systems with continuous degrees of freedom giving rise to a continuum density of states, as it is commonly found in Lattice Gauge Theories and in some Statistical Mechanics systems. We show that the method possesses an exponential error suppression that allows us to estimate the density of states over several orders of magnitude with nearly-constant relative precision. We explain how ergodicity issues can be avoided and how expectation values of arbitrary observables can be obtained within this framework. We then demonstrate the method using Compact U(1) Lattice Gauge Theory as a show case. A thorough study of the algorithm parameter dependence of the results is performed and compared with the analytically expected behaviour. We obtain high precision values for the critical coupling for the phase transition and for the peak value of the specific heat for lattice sizes ranging from 84 to 204. Our results perfectly agree with the reference values reported in the literature, which covers lattice sizes up to 184. Robust results for the 204 volume are obtained for the first time. This latter investigation, which, due to strong metastabilities developed at the pseudo-critical coupling of the system, so far has been out of reach even on supercomputers with importance sampling approaches, has been performed to high accuracy with modest computational resources. This shows the potential of the method for studies of first order phase transitions. Other situations where the method is expected to be superior to importance sampling techniques are pointed out

    A recurrent epidermoid cyst of the spleen: report of a case and literature review

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    BACKGROUND: Splenic cysts are rare disease. Epidermoid cysts of the spleen belong to the primary nonparasitic splenic cysts group. They are an unusual event in surgical practice. Usually, epidermoid cysts occur in children and young female. Most often, they are asymptomatic, but they may present with abdominal discomfort. CASE PRESENTATION: We are reporting a rare case of a 23-year-old female came to our attention with history of intermittent pain and previously undergone two times to laparoscopic decapsulation of the cyst in others institutions. During hospitalization, serum and intracystic levels of tumor marker CA19-9 increased. Enhanced CT of the abdomen showed recurrent large cyst in the upper pole of the spleen with satellite nodules. Laparotomic total splenectomy was performed. Histopathological and immunoreactive examinations were executed, and they revealed stratified squamous epithelium on the inner surface of cystic wall, which was positive for EMA, CEA, and CA19-9. The diagnosis of epidermoid cyst was confirmed. CONCLUSIONS: Recently, the surgical approach is changing towards conservative treatments in order to save the spleen in young patients for immunological reasons. Sometimes, this target is not achievable. In such circumstances, like recurrent large cyst, anomalous anatomical relationship to the surrounding tissues, total splenectomy is safe and necessary

    Ophthalmic Complications of Bariatric Surgery

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    Obesity is increasing vastly in the world, and the number of bariatric surgeries being performed is also increasing. Patients being submitted to bariatric surgeries, especially malabsorptive procedures, have an increased risk of developing nutrient deficiencies, which can culminate in symptomatic hypovitaminosis, if supplementation is not done correctly. The eye and the optic system need an adequate level of several vitamins and minerals to perform properly, especially vitamin A, and this article wants to cover the main nutrients involved, the possible ophthalmic complications that can arise by their deficiency, and the management of those complications

    Anticipated impact of the 2009 Four Corners raid and arrests

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    Archaeological looting on United States federal land has been illegal for over a century. Regardless, the activity has continued in the Four Corners region. This paper discusses how the 1979 Archaeological Resources Protection Act (ARPA) can be viewed as sumptuary law, and within a sumptuary context, subversion can be anticipated. An analysis of 1986 and June 2009 federal raids in the Four Corners will exemplify this point by identifying local discourses found in newspapers both before and after each raid, which demonstrate a sumptuary effect. Ultimately, this paper concludes that looting just adapted, rather than halted, after each federal raid and that understanding this social context of continued local justification and validation of illegal digging is a potential asset for cultural resource protection

    Mechanical analysis of infant carrying in hominoids

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    In all higher nonhuman primates, species survival depends upon safe carrying of infants clinging to body hair of adults. In this work, measurements of mechanical properties of ape hair (gibbon, orangutan, and gorilla) are presented, focusing on constraints for safe infant carrying. Results of hair tensile properties are shown to be species-dependent. Analysis of the mechanics of the mounting position, typical of heavier infant carrying among African apes, shows that both clinging and friction are necessary to carry heavy infants. As a consequence, a required relationship between infant weight, hair–hair friction coefficient, and body angle exists. The hair–hair friction coefficient is measured using natural ape skin samples, and dependence on load and humidity is analyzed. Numerical evaluation of the equilibrium constraint is in agreement with the knuckle-walking quadruped position of African apes. Bipedality is clearly incompatible with the usual clinging and mounting pattern of infant carrying, requiring a revision of models of hominization in relation to the divergence between apes and hominins. These results suggest that safe carrying of heavy infants justify the emergence of biped form of locomotion. Ways to test this possibility are foreseen here
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