Normalized additional velocity distribution: a fast sample analysis for dark matter or modified gravity models

Here we propose a fast and complementary approach to study galaxy rotation curves directly from the sample data, instead of first performing individual rotation curve fits. The method is based on a dimensionless difference between the observational rotation curve and the expected one from the baryonic matter ($\delta V^2$). It is named as Normalized Additional Velocity (NAV). Using 153 galaxies from the SPARC galaxy sample, we find the observational distribution of $\delta V^2$. This result is used to compare with the model-inferred distributions of the same quantity. We consider the following five models to illustrate the method, which include a dark matter model and four modified gravity models: Burkert profile, MOND, Palatini $f(R)$ gravity, Eddington-inspired-Born-Infeld (EiBI) and general relativity with renormalization group effects (RGGR). We find that the Burkert profile, MOND and RGGR have reasonable agreement with the observational data, the Burkert profile being the best model. The method also singles out specific difficulties of each one of these models. Such indications can be useful for future phenomenological improvements. The NAV method is sufficient to indicate that Palatini $f(R)$ and EiBI gravities cannot be used to replace dark matter in galaxies, since their results are in strong tension with the observational data sample.Comment: 17 pages, 7 figures, 6 tables. Code available at https://github.com/davi-rodrigues/NAVanalysi

Green coffee beans feature extractor using image processing

This study offers a novel solution to deal with the low signal-to-noise ratio and slow execution rate of the first derivative edge detection algorithms namely, Roberts, Prewitt and Sobel algorithms. Since the two problems are brought about by the complex mathematical operations being used by the algorithms, these were replaced by a discriminant. The developed discriminant, equivalent to the product of total difference and intensity divided by the normalization values, is based on the “pixel pair formation” that produces optimal peak signal to noise ratio. Results of the study applying the discriminant for the edge detection of green coffee beans shows improvement in terms of peak signal to noise ratio (PSNR), mean square error (MSE), and execution time. It was determined that accuracy level varied according to the total difference of pixel values, intensity, and normalization values. Using the developed edge detection technique led to improvements in the PSNR of 2.091%, 1.16 %, and 2.47% over Sobel, Prewitt, and Roberts respectively. Meanwhile, improvement in the MSE was measured to be 13.06%, 7.48 %, and 15.31% over the three algorithms. Likewise, improvement in execution time was also achieved at values of 69.02%, 67.40 %, and 65.46% over Sobel, Prewitt, and Roberts respectively

SinR is a mutational target for fine-tuning biofilm formation in laboratory-evolved strains of Bacillus subtilis

Background: Bacteria often form multicellular, organized communities known as biofilms, which protect cells from a variety of environmental stresses. During biofilm formation, bacteria secrete a species-specific matrix; in Bacillus subtilis biofilms, the matrix consists of protein polymers and exopolysaccharide. Many domesticated strains of B. subtilis have a reduced ability to form biofilms, and we conducted a two-month evolution experiment to test whether laboratory culturing provides selective pressure against biofilm formation in B. subtilis. Results: Bacteria grown in two-month-long batch culture rapidly diversified their biofilm-forming characteristics, exhibiting highly diverse colony morphologies on LB plates in the initial ten days of culture. Generally, this diversity decreased over time; however, multiple types of colony morphology remained in our final two-month-old populations, both under shaking and static conditions. Notably, while our final populations featured cells that produce less biofilm matrix than did the ancestor, cells overproducing biofilm matrix were present as well. We took a candidate-gene approach to identify mutations in the strains that overproduced matrix and found point mutations in the biofilm-regulatory gene sinR. Introducing these mutations into the ancestral strain phenocopied or partially phenocopied the evolved biofilm phenotypes. Conclusions: Our data suggest that standard laboratory culturing conditions do not rapidly select against biofilm formation. Although biofilm matrix production is often reduced in domesticated bacterial strains, we found that matrix production may still have a fitness benefit in the laboratory. We suggest that adaptive specialization of biofilm-forming species can occur through mutations that modulate biofilm formation as in B. subtilis. Electronic supplementary material The online version of this article (doi:10.1186/s12866-014-0301-8) contains supplementary material, which is available to authorized users

Smart Wheelchair with Dual Control using Touchpad and Android Mobile Device

The general objective of the design was to develop a touchpad controlled Android-based electronic wheelchair. It aimed to construct the Android-based circuitry and program for the path finding mechanism of the drive system and interface the Arduino-based circuit to the electronic wheelchair setup. It was designed to evaluate the system in terms of the speed of the electronic wheelchair, reliability of the sensors to avoid obstacle, and ease of use of the wheelchair. C Programming Language was used by the system to control and manipulate the microcontroller, Gizduino AtMega644. The Android application was programmed using the Java Language and Eclipse as the IDE. Its ports were used to interface input and output devices such as the ultrasonic sensors, infrared proximity sensor, touchpad, Bluetooth module, motor and motor driver. There was a satisfactory rating for the evaluation of the system while the Android software was rated excellent as a navigational controller

Palatini f(R)f(R) gravity tests in the weak field limit: Solar System, seismology and galaxies

Palatini $f(R)$ gravity is probably the simplest extension of general relativity (GR) and the simplest realization of a metric-affine theory. It has the same number of degrees of freedom as GR and, in vacuum, it is straightforwardly mapped into GR with a cosmological constant. The mapping between GR and Palatini $f(R)$ inside matter is possible but at the expense of reinterpreting the meaning of the matter fields. The physical meaning and consequences of such mapping will depend on the physical context. Here we consider three such cases within the weak field limit: Solar System dynamics, planetary internal dynamics (seismology), and galaxies. After revising our previous results on the Solar System and Earth's seismology, we consider here the possibility of $f(R)$ Palatini as a dark matter candidate. For any $f(R)$ that admits a polynomial approximation in the weak field limit, we show here, using SPARC data and a recent method that we proposed, that the theory cannot be used to replace dark matter in galaxies. We also show that the same result applies to the Eddington-inspired Born-Infeld gravity. Differently from the metric $f(R)$ case, the rotation curve data are sufficient for this conclusion. This result does not exclude a combination of modified gravity and dark matter.Comment: 20 pages, 2 figures. Submitted as a research article related to the conference Metric-Affine Frameworks for Gravity 202

Intelligent Temperature-Controlled Poultry Feed Dispensing System with Fuzzy Logic Algorithm

This study introduces a novel fuzzy logic algorithm tailored to the thermoneutral zone of poultry, offering a precise and adaptive approach to feed dispensation. This involved the utilization of an LCD module to present essential information such as the selected age, real-time ambient temperature, current time, and the dispensed feed quantity. Data gathered during the process were stored in a memory device. The design of the fuzzy logic algorithm centered on the thermoneutral zone of the chicken serves as the determinant for feed dispensed by the system. It's crucial to note that while the system lacked artificial intelligence (AI), its logical analysis operated based on the fuzzy logic algorithm. Rigorous testing ensued, encompassing the comparison of feed dispensation between automated and manual systems and the assessment of feed waste and broiler weight.  Significant feed waste reduction in the first week demonstrated the efficacy of the fuzzy-based method, with consistently low p-values of 0.00069, 0.015195, and 0.034 across subsequent weeks confirming the consistent outperformance in broiler weight compared to the traditional feeding technique. The findings contribute to the advancement of temperature-based poultry feed systems, addressing key challenges in optimizing feed quantity. The study successfully met its objectives, demonstrating the system's capability to dispense feeds effectively across varying ambient temperatures.  Notably, the study revealed a consistent alignment of system outputs with those obtained from a digital thermometer and digital weighing scale, confirming the accuracy and reliability of the temperature-based feed dispensing system

Determinantes de uma eleição errada ao escolher medicamentos de venda livre

Este estudo avalia a probabilidade de confusão do consumidor para seis categorias de medicamentos de venda livre. As estimativas realizam-se com base em um desenho experimental onde o tempo e a presença das marcas são as variáveis manipuladas. Adicionalmente, controla-se por memorização e hábito de consumo da marca. Através de três tipos de análises (tabela de contingência, árvores de decisão e regressão logit), os resultados indicam que a memorização e a presença da marca são duas variáveis que reduzem a probabilidade de confusão. Os resultados não são generalizáveis a outras categorias, sem embargo, a memorização e a presença da marca se mostraram variáveis importantes ao avaliar a probabilidade de confusão do consumidor.Cette étude évalue la probabilité de confusion du consommateur pour six catégories de médicaments de vente libre. Les estimations sont réalisées sur base d'un design expérimental dans lequel le temps et la présence des marques sont les variables manipulées. En outre, un contrôle est effectué par rappel et habitudes de consommation de la marque. Après avoir utilisé trois types d'analyses (tableau de contingence, arbre de régression et régression logit), les résultats indiquent que le rappel et la présence de la marque sont deux variables qui réduisent la probabilité de confusion. Les résultats ne sont pas généralisables pour d'autres catégories, cependant, le rappel et la présence de la marque sont des variables qui résultent importantes pour évaluer la probabilité de confusion du consommateur.Este estudio evalúa la probabilidad de confusión del consumidor para seis categorías de medicamentos de venta libre. Las estimaciones se realizan con base en un diseño experimental donde el tiempo y la presencia de las marcas son las variables manipuladas. Adicionalmente, se controla por recordación y hábito de consumo de la marca. A través de tres tipos de análisis (tabla de contingencia, regresión de árbol y regresión LO GIT), los resultados indican que la recordación y la presencia de la marca son dos variables que reducen la probabilidad de confusión. Los resultados no son generalizables a otras categorías; sin embargo, la recordación y presencia de la marca sí resultan ser variables importantes al evaluar la probabilidad de confusión del consumidor.This study evaluates the probability of confusion among consumers regarding six categories of over-the-counter medications. The estimates are based on an experimental design in which time and the presence of brands are the variables addressed. Additionally, it is controlled using recollection and consumption habits regarding brands. Using three types of analysis (contingency table, tree regression and logic regression), the results show that recollection and the presence of brands are the two variables that reduce the probability of confusion. The results are not applicable to other categories; however, recollection and the presence of brands do turn out to be significant variables when evaluating the probability of consumer confusion

Structure, Configuration And Sizing Of Ni Nanoparticles Generated By Ultrafast Laser Ablation In Different Media

In recent years, nickel nanoparticles (NPs) have increased scientific interest because of their extensive prospects in catalysts, information storage, large-scale batteries and biomedicine. Several works on Ni NPs generation by laser ablation have appeared in the literature in the last years, using different pulsed laser regimes and different media have been published recently. In this work we analyze the characteristics of species, structure (bare core or core-shell), configuration and size distribution of NPs generated by fs pulse laser ablation over a Ni solid target in n-heptane and water. We explore the presence of NiO-Ni core-shell and hollow Ni (or air-Ni) NPs in the colloids obtained. These were experimentally characterized using AFM and TEM microscopy, as well as Optical Extinction Spectroscopy (OES). Extinction spectra were modeled using Mie theory through an appropriate modification of the complex experimental dielectric function, taking into account a size-dependent corrective term for each free and bound electron contribution. Experimental UV-visible-NIR spectra were reproduced considering a size distribution of bare core, hollow and core-shell structures NPs. In both media, Ni NPs shape and size distribution agrees with that derived from TEM and AFM analysis.954