Adaptive Neural Compilation

This paper proposes an adaptive neural-compilation framework to address the problem of efficient program learning. Traditional code optimisation strategies used in compilers are based on applying pre-specified set of transformations that make the code faster to execute without changing its semantics. In contrast, our work involves adapting programs to make them more efficient while considering correctness only on a target input distribution. Our approach is inspired by the recent works on differentiable representations of programs. We show that it is possible to compile programs written in a low-level language to a differentiable representation. We also show how programs in this representation can be optimised to make them efficient on a target distribution of inputs. Experimental results demonstrate that our approach enables learning specifically-tuned algorithms for given data distributions with a high success rate.Comment: Submitted to NIPS 2016, code and supplementary materials will be available on author's pag

Efficient Relaxations for Dense CRFs with Sparse Higher Order Potentials

Dense conditional random fields (CRFs) have become a popular framework for modelling several problems in computer vision such as stereo correspondence and multi-class semantic segmentation. By modelling long-range interactions, dense CRFs provide a labelling that captures finer detail than their sparse counterparts. Currently, the state-of-the-art algorithm performs mean-field inference using a filter-based method but fails to provide a strong theoretical guarantee on the quality of the solution. A question naturally arises as to whether it is possible to obtain a maximum a posteriori (MAP) estimate of a dense CRF using a principled method. Within this paper, we show that this is indeed possible. We will show that, by using a filter-based method, continuous relaxations of the MAP problem can be optimised efficiently using state-of-the-art algorithms. Specifically, we will solve a quadratic programming (QP) relaxation using the Frank-Wolfe algorithm and a linear programming (LP) relaxation by developing a proximal minimisation framework. By exploiting labelling consistency in the higher-order potentials and utilising the filter-based method, we are able to formulate the above algorithms such that each iteration has a complexity linear in the number of classes and random variables. The presented algorithms can be applied to any labelling problem using a dense CRF with sparse higher-order potentials. In this paper, we use semantic segmentation as an example application as it demonstrates the ability of the algorithm to scale to dense CRFs with large dimensions. We perform experiments on the Pascal dataset to indicate that the presented algorithms are able to attain lower energies than the mean-field inference method

Recovery of Total Chromium from Tannery Wastewater by Carbonization Application

A carbonization process was carried out for the recovery of chromium from wastewater by chemical treatment with sodium hydroxide as a basic solution in contact with the precursor material at different concentrations [1:0.15 (%w/w) - 1:0.20 (%w/w)]. The physical treatment was carried out with carbonization at 700∘C for a period of 2 hours. The obtained samples were characterized by elemental analysis, thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), atomic absorption spectroscopy, and surface area analysis (BET) to validate the evidence of metal recovery. The results indicate that the percentage of total chromium recovery was 47.62% with respect to the uncarbonized material, establishing that the best carbonization variables are at 700∘C and concentration 1:0.20% w/w for 2 hours. Keywords: tannery industry, carbonization, recovery, total chromium. Resumen Se realizó un proceso de carbonización para la recuperación de cromo a partir de aguas residuales mediante un tratamiento químico con hidróxido de sodio como solución básica en contacto con el material precursor a diferentes concentraciones [1:0,15 (%p/p)- 1:0,20 (%p/p)], el tratamiento físico se realizó con la carbonización a 700∘C por un lapso de 2 horas. Las muestras obtenidas se caracterizaron mediante análisis elemental, análisis termogravimétrico (TGA), espectroscopia infrarroja por transformada de Fourier (FT-IR), espectroscopia de absorción atómica y análisis de área superficial (BET) para validar la evidencia de la recuperación del metal. Los resultados indican que el porcentaje de recuperación de cromo total es de 47,62% respecto del material sin carbonizar estableciendo que las mejores variables de carbonización son 700 ∘C y concentración 1:0.20 %p/p por 2 horas. Palabras Clave: Industria curtiembre, carbonización, recuperación, cromo total

Associations between vaccination and antimicrobial consumption in Danish pig herds, 2013

Antimicrobial agents are being used in modern swine production worldwide, generating concern in regards to the development of antimicrobial resistance. Identifying efficient alternatives has therefore become a subject of interest. The aim of this study was to explore the impact of routinely used vaccination as an alternative to antimicrobial consumption in weaner pig herds. The hypothesis was that herds with increased use of vaccination would have a lower antimicrobial consumption. Data were obtained from the Danish VetStat database in which prescriptions of medication for livestock are recorded as well as the Danish Central Husbandry Register. All Danish one-site pig herds, active in year 2013, with \u3e50 sows and \u3e200 weaners were selected for the study. Initially, data were analysed using a univariable model, and secondly a multivariable linear regression model was applied. The analyses included use of three different vaccines against Porcine Circovirus Type 2 (PCV2), Mycoplasma hyopneumoniae (M_HYO) and Lawsonia intracellularis (LAW), respectively, as well as annual production measured as number of weaners produced in a year. The outcome was the average antimicrobial consumption measured in animal daily does (ADD) per weaner pig. Out of the 1,513 herds selected for the study, 1,415 herds had antimicrobials prescribed for gastrointestinal disorders, and 836 for respiratory disorders. PCV2 vaccine was used in 880 herds, M_HYO vaccine in 787 and LAW vaccine was the least used, with 115 herds using it. The results suggested that antimicrobials to some extent were being used for other disease categories than those officially prescribed by the veterinarians. On average, herds using the different combinations of vaccines had higher use of antimicrobials than herds not using the vaccines – probably as a result of health problems in the herds existing prior to the initiation of vaccine use. Information about vaccination protocols, health status, biosecurity, and management practices was not available limiting the ability to assess causality

Magnetic breakdown in a normal-metal - superconductor proximity sandwich

We study the magnetic response of a clean normal-metal slab of finite thickness in proximity with a bulk superconductor. We determine its free energy and identify two (meta-)stable states, a diamagnetic one where the applied field is effectively screened, and a second state, where the field penetrates the normal-metal layer. We present a complete characterization of the first order transition between the two states which occurs at the breakdown field, including its spinodals, the jump in the magnetization, and the latent heat. The bistable regime terminates at a critical temperature above which the sharp transition is replaced by a continuous cross-over. We compare the theory with experiments on normal-superconducting cylinders.Comment: 7 pages Revtex, 3 Postscript figures, needs psfig.te

Breastfeeding and Respiratory Tract Infections during the First 2 Years of Life.

Breastfeeding protects against respiratory tract infections (RTIs) in infants [1–3], but whether its effects persist beyond that age is not well understood. Some studies have reported that protection diminishes soon after weaning [2], while others have found that it extends until the age of 2 years [4] or more [5, 6]. It is noteworthy that many previous studies grouped RTIs broadly into upper or lower tract infections, rather than studying specific diseases [3, 7], and few adjusted adequately for confounding factors [5] or investigated a possible effect modification by sex, which had been suggested by several studies showing a stronger protection in girls [8, 9]. This study aimed to quantify the protective effect of breastfeeding against RTIs during the first 2 years of life, while adjusting for potential confounding factors and testing whether the effect varied by sex. We analysed data from the Leicester Respiratory Cohorts, a population-based random sample of children from Leicestershire, UK, which has been described in detail elsewhere [10]. For this analysis we included only children born between 1996 and 1997 who were aged 1–1.99 years at the date of the first survey in 1998. Parents completed a standardised questionnaire that requested detailed information on breastfeeding and respiratory symptoms. We assessed the duration of breastfeeding (no breastfeeding, ⩽6 months or >6 months), the prevalence of frequent colds (>6 episodes), ear infections and croup within the last 12 months, and any episodes of bronchiolitis or pneumonia. We extracted perinatal data and demographic information from maternity records. The Leicestershire Health Authority Research Ethics Committee approved the study. The survey requested information on a number of RTIs for each child, so we first performed an omnibus logistic regression to determine whether breastfeeding was associated with the occurrence of any RTI. By reforming the data into long format, this omnibus logistic regression also adjusted for the clustering of observations within each child [11]. Following a significant omnibus test, we performed unadjusted and adjusted logistic regressions to determine which RTIs were affected by breastfeeding practice. Adjusted models controlled for sex, ethnicity, socioeconomic status (Townsend deprivation score [12]), perinatal factors (gestational age, birthweight, birth season), environmental factors ( pre- and post-natal maternal smoking, number of older siblings, day care attendance) and parental history of asthma, hay fever and bronchitis. We tested for effect modification by sex by adding interaction terms into adjusted models. Finally, we performed a sensitivity analysis including a subgroup of children with information on exact breastfeeding duration, by using breastfeeding as a continuous exposure, rather than categorical. All analyses were performed in Stata (version 14.2, Stata Corporation, Austin, TX, USA). The survey in 1998 was sent to 5400 families with children aged between 1 and 1.99 years. Questionnaires were returned by 4100 parents (response rate of 76%). After excluding 47 children who had no breastfeeding information and 13 children born extremely prematurely (gestational age of <28 weeks [13]), 4040 children remained in the analysis. Of these, 52% were boys, 81% were white and 19% were of South Asian ethnic origin, 1659 (41%) had never been breastfed, 1639 (41%) had been breastfed for ⩽6 months and 742 (18%) for >6 months. Of the 4040 included children, 769 (19%) were reported by their parents to have had frequent colds, 1685 (42%) ear infections and 293 (7%) croup within the last 12 months. Any episodes of bronchiolitis were reported for 453 children (11%) and pneumonia for 53 (1%)Peer-reviewedPublisher Versio

Grooming-at-a-distance by exchanging calls in non-human primates

International audienceThe 'social bonding hypothesis' predicts that, in large social groups, functions of gestural grooming should be partially transferred to vocal interactions. Hence, vocal exchanges would have evolved in primates to play the role of grooming-at-a-distance in order to facilitate the maintenance of social cohesion. However, there are few empirical studies testing this hypothesis. To address this point, we compared the rate of contact call exchanges between females in two captive groups of Japanese macaques as a function of female age, dominance rank, genetic relatedness and social affinity measured by spatial proximity and grooming interactions. We found a significant positive relationship between the time spent on grooming by two females and the frequency with which they exchanged calls. Our results conform to the predictions of the social bonding hypothesis, i.e. vocal exchanges can be interpreted as grooming-at-a-distanc

Serre's reduction of linear functional systems

Serre's reduction aims at reducing the number of unknowns and equations of a linear functional system (e.g., system of partial differential equations, system of differential time-delay equations, system of difference equations). Finding an equivalent representation of a linear functional system containing fewer equations and fewer unknowns generally simplifies the study of its structural properties, its closed-form integration as well as of different numerical analysis issues. The purpose of this paper is to present a constructive approach to Serre's reduction for determined and underdetermined linear functional systems