Modelling the emergence of whisker barrels

Brain development relies on an interplay between genetic specification and self-organization. Striking examples of this relationship can be found in the somatosensory brainstem, thalamus, and cortex of rats and mice, where the arrangement of the facial whiskers is preserved in the arrangement of cell aggregates to form precise somatotopic maps. We show in simulation how realistic whisker maps can self-organize, by assuming that information is exchanged between adjacent cells only, under the guidance of gene expression gradients. The resulting model provides a simple account of how patterns of gene expression can constrain spontaneous pattern formation to faithfully reproduce functional maps in subsequent brain structures

Longitudinal vehicle dynamics : a comparison of physical and data-driven models under large-scale real-world driving conditions

Mathematical models of vehicle dynamics will form essential components of future autonomous vehicles. They may be used within inverse or forward control loops, or within predictive learning systems. Often, nonlinear physical models are used in this context, which, though conceptually simple (especially for decoupled, longitudinal dynamics), may be computationally costly to parameterise and also inaccurate if they omit vehicle-specific dynamics. In this study we sought to determine the relative merits of a commonly used nonlinear physical model of vehicle dynamics versus data-driven models in large-scale real-world driving conditions. To this end, we compared the performance of a standard nonlinear physical model with a linear state-space model and a neural network model. The large-scale experimental data was obtained from two vehicles; a Lancia Delta car and a Jeep Renegade sport utility vehicle. The vehicles were driven on regular, public roads, during normal human driving, across a range of road gradients. Both data-driven models outperformed the physical model. The neural network model performed best for both vehicles; the state-space model performed almost as well as the neural network for the Lancia Delta, but fell short for the Jeep Renegade whose dynamics were more strongly nonlinear. Our results suggest that the linear data-driven model gives a good trade-off in accuracy and simplicity, whilst the neural network model is most accurate and is extensible to more nonlinear operating conditions, and finally that the widely used physical model may not be the best choice for control design

Resistencia a la humedad y al secado de un suelo estabilizado con cal modificado con escoria de acero y reforzado con fibras

The investigation dealt with the stabilization of expansive soil with combinations of lime, steel slag and reinforced with two types of fibres, copper filaments and polypropylene fibres. The investigation began with the characterization of the soil for its geotechnical properties. The initial consumption of lime required for the modification of the soil properties was determined from the Eades and Grim pH test. Cylindrical specimens of soil with dimensions 38 mm x 76 mm were cast using this lime content as a stabilizer along with varying quantities of steel slag for determination of optimum steel slag content. The pure lime stabilized soil as well as lime-steel slag modified soil specimens were reinforced with different proportions of copper filaments for determination of optimum fibre content. One dosage of polypropylene fibres was also adopted as reinforcement in specimen preparation. The optimal combinations identified were then subjected to a maximum of three cycles of wetting and drying followed by determination of unconfined compression strength (UCS). The expansive soil required a minimum of 3% lime for its modification. The optimum dosage of steel slag was identified as 5% and optimum copper filament content as 1%. Polypropylene content of 0.3% was also adopted as one combination. The results of the investigation revealed that lime stabilized fibre-reinforced soil with copper filaments was the most durable combination followed by polypropylene fibres. The introduction of steel slag in the mix could not generate enough beneficial durability to the soil after three cycles of wetting and drying.La investigación se ocupó de la estabilización del suelo expansivo con combinaciones de cal, escoria de acero y reforzado con dos tipos de fibras, filamentos de cobre y fibras de polipropileno. La investigación comenzó con la caracterización del suelo por sus propiedades geotécnicas. El consumo inicial de cal requerido para la modificación de las propiedades del suelo se determinó a partir de la prueba de pH Eades y Grim. Se moldearon muestras cilíndricas de suelo con dimensiones de 38 mm x 76 mm utilizando este contenido de cal como estabilizador junto con cantidades variables de escoria de acero para la determinación del contenido óptimo de escoria de acero. El suelo estabilizado con cal pura y las muestras de suelo modificadas con escoria de acero de cal se reforzaron con diferentes proporciones de filamentos de cobre para determinar el contenido óptimo de fibra. También se adoptó una dosis de fibras de polipropileno como refuerzo en la preparación de muestras. Las combinaciones óptimas identificadas se sometieron luego a un máximo de tres ciclos de humectación y secado, seguido de la determinación de la resistencia a la compresión no confinada (UCS). El suelo expansivo requirió un mínimo de 3% de cal para su modificación. La dosis óptima de escoria de acero se identificó como 5% y el contenido óptimo de filamento de cobre como 1%. El contenido de polipropileno del 0.3% también se adoptó como una combinación. Los resultados de la investigación revelaron que el suelo reforzado con fibra estabilizado con cal con filamentos de cobre fue la combinación más duradera seguida por las fibras de polipropileno. La introducción de escoria de acero en la mezcla no pudo generar suficiente durabilidad beneficiosa para el suelo después de tres ciclos de humectación y secado

Multivariate side-band subtraction using probabilistic event weights

A common situation in experimental physics is to have a signal which can not be separated from a non-interfering background through the use of any cut. In this paper, we describe a procedure for determining, on an event-by-event basis, a quality factor ($Q$-factor) that a given event originated from the signal distribution. This procedure generalizes the "side-band" subtraction method to higher dimensions without requiring the data to be divided into bins. The $Q$-factors can then be used as event weights in subsequent analysis procedures, allowing one to more directly access the true spectrum of the signal.Comment: 17 pages, 9 figure

NMR Determination of Oligonucleotide Structure

This unit provides an overview of the use of NMR to determine oligonucleotide structure. It covers basic NMR spectral properties, acquisition of interproton distance restraints and torsion angle restraints, structure refinement, assessment of the quality of the structure obtained. Software programs used in the process are also described.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143742/1/cpnc0702.pd

Agronomic and greenhouse gas assessment of land applied anaerobically digested swine manure

Non-Peer ReviewedManagement of animal wastes from intensive livestock operations (ILO) must be economically feasible, environmentally friendly and socially acceptable. Anaerobic digestion is a promising technology that could provide an option for managing animal waste that may reduce greenhouse gas emissions by utilizing the biogas produced during digestion to displace fossil-fuels and by reducing emissions during lagoon storage. A three-year study was conducted at two locations, Swift Current and Melfort, to compare the agronomic performance and gaseous N loss of land-applied anaerobically digested swine manure (ADSM) to conventionally treated swine manure (CTSM). Treatments included spring and fall applications of CTSM and ADSM at a 1x rate (10,000 and 7,150 L ha-1 respectively) applied each year, and a 3x rate (30,000 and 21,450 L ha-1 respectively) applied once at the beginning of the study. A treatment receiving commercial fertilizer (UAN) and a check (no N) were also included. Nitrogen use efficiency for single applications of ADSM or CTSM at the 3x rate were lower than three annual applications at the 1x rate, while UAN was intermediate. Nitrogen use efficiency of ADSM and CTSM applied in the fall was equal to spring when applied at 1x rate and, in general, agronomic performance of ADSM was similar or better than CTSM. Ammonia loss from ADSM was similar to CTSM, except for CTSM at the 3x rate applied in the fall at Melfort and in the spring at Swift Current, which had significantly higher losses than all other treatments. The percentage of applied N lost as N2O measured at the Melfort site was generally higher for treatments receiving CTSM compared to ADSM or UAN, and losses from ADSM and UAN were similar. The results from this study suggest that ADSM is equal or better than CTSM in terms of agronomic performance, but has lower environmental impact with respect to gaseous N loss

A Novel Approach to the Common Due-Date Problem on Single and Parallel Machines

This paper presents a novel idea for the general case of the Common Due-Date (CDD) scheduling problem. The problem is about scheduling a certain number of jobs on a single or parallel machines where all the jobs possess different processing times but a common due-date. The objective of the problem is to minimize the total penalty incurred due to earliness or tardiness of the job completions. This work presents exact polynomial algorithms for optimizing a given job sequence for single and identical parallel machines with the run-time complexities of $O(n \log n)$ for both cases, where $n$ is the number of jobs. Besides, we show that our approach for the parallel machine case is also suitable for non-identical parallel machines. We prove the optimality for the single machine case and the runtime complexities of both. Henceforth, we extend our approach to one particular dynamic case of the CDD and conclude the chapter with our results for the benchmark instances provided in the OR-library.Comment: Book Chapter 22 page

Anisotropic low field behavior and the observation of flux jumps in CeCoIn5

The magnetic behavior of the heavy fermion superconductor CeCoIn5 has been investigated. The low field magnetization data show flux jumps in the mixed state of the superconducting phase in a restricted range of temperature. These flux jumps begin to disappear below 1.7 K, and are completely absent at 1.5 K. The magnetization loops are asymmetric, suggesting that surface and geometrical factors dominate the pinning in this system. The lower critical field (Hc1), obtained from the magnetization data, shows a linear temperature dependence and is anisotropic. The calculated penetration depth is also anisotropic, which is consistent with the observation of an anisotropic superconducting gap in CeCoIn5. The critical currents, determined from the high field isothermal magnetization loops, are comparatively low (around 4000 A/cm2 at 1.6 K and 5 kOe).Comment: 4 pages 3 figure

CD4-T Cells as a Predictor of Immune Status and Its Outcomes Following Second-Line Combination Antiretroviral Therapy in Adult HIV-1 Infected Patients Attending Apin/Juth HIV Clinic in Jos, Plateau State, Nigeria

Deficiency in immune cell number or activity is a cardinal feature of HIV.  Second line antiretroviral therapy is geared towards improving immune cell activity and improving treatment outcomes. More people are now accessing free combination antiretroviral therapy through public health programmes in resource limited settings. There is currently no third line therapy for patients failing second line therapy in most of these programmes and data on effectiveness of second line antiretroviral therapy are limited. To adequately address and prepare for this scenario, critical assessments of the outcomes of second-line cART are needed. This is a retrospective cohort study of patients accessing second line cART at the APIN/ JUTH, Jos adult HIV clinic from 2004 to 2018, to determine the proportion of patients failing second line cART, to evaluate time to immunologic failure, time to lost to follow up and time to death using Kaplan Meier estimates. Immunological failure occurs when there is a fall of CD4 counts to pre-therapy baseline (or below) or 50% fall from the on-treatment peak value (if known) or persistent CD4 levels below 100 cells/mm3 6 months after ART initiation. A total of 285 patients were included in the study, with a mean age of 45±9.5 years. Females where 194 (68.1%) All the patients were on boosted protease inhibitor, the predominant combination antiretroviral therapy for second line regimen was Lopinavir boosted with ritonavir in combination with Tenofovir, Lamivudine and Zidovudine (43.9%). The baseline CD4 count was 134 (IQR 54-272). The CD4 count increased to 339 (IQR213-498) at 72 weeks.   In conclusion, Second line cART immunologic failure rates are low in our cohort and patient stay longer on cART before failure. Keywords: CD4 cells, Immunologic failure, Antiretroviral therapy DOI: 10.7176/JHMN/107-02 Publication date: April 30th 202

Dibaryon Spectroscopy

The AdS/CFT correspondence relates dibaryons in superconformal gauge theories to holomorphic curves in Kaehler-Einstein surfaces. The degree of the holomorphic curves is proportional to the gauge theory conformal dimension of the dibaryons. Moreover, the number of holomorphic curves should match, in an appropriately defined sense, the number of dibaryons. Using AdS/CFT backgrounds built from the generalized conifolds of Gubser, Shatashvili, and Nekrasov (1999), we show that the gauge theory prediction for the dimension of dibaryonic operators does indeed match the degree of the corresponding holomorphic curves. For AdS/CFT backgrounds built from cones over del Pezzo surfaces, we are able to match the degree of the curves to the conformal dimension of dibaryons for the n'th del Pezzo surface, n=1,2,...,6. Also, for the del Pezzos and the A_k type generalized conifolds, for the dibaryons of smallest conformal dimension, we are able to match the number of holomorphic curves with the number of possible dibaryon operators from gauge theory.Comment: 30 pages, 6 figures, corrected refs; v3 typos correcte