A New Mathematical Model For Assessment of Memorization Dynamics

Se propone un nuevo modelo de memoria basado en el análisis de regresión y las curvas exponenciales de aprendizaje. La eficacia del modelo se verifica con varios tipos de experimentos incluyendo la aversión a la comida en caracoles, el aprendizaje de laberintos en ratas y las pruebas de memoria en adultos y niños. El modelo también se pone a prueba en drogadictos y alcohólicos. Los resultados de las pruebas de bondad de ajuste indican que nuestro modelo puede ser empleado con precisión para predecir las dinámicas de la memoria en diversos experimentos y poblaciones. También puede emplearse el modelo para predecir tanto la ejecución grupal como la individual. Se comenta la aplicación del modelo para detectar el deterioro de la memoria, así como las limitaciones del mismo.A new memory model is proposed based on regression analysis and exponential- shaped learning curves. The efficacy of the model is tested with several types of experiments including food aversion in snails, maze learning in rats and memory tests for adults and children. The model is also tested on drug abusers and alcoholics. The results of goodness of fit tests indicate that our model can accurately be used to predict the memory dynamics of diverse experiments and populations. The model can also be used to predict both group and individual performance. The application of the model to detect memory impairment is discussed, as are limitation

Simulation of the Betatron Magnetic Field at the Electron Beam Displacement in Comsol Multiphysics

This article describes the betatron magnetic field simulation in Comsol Multiphysics software package. The model makes it possible to evaluate the betatron focusing properties at the moment of electron displacement onto the target. The simulation results coincide with the experiment described earlier. The study shows the vertical size of the target affects the focal spot size. However, a target size decrease leads to low output dose, since not all electrons reach it. Therefore, the vertical size of the target should be greater than or equal to the vertical dimension of the accelerated beam

Overall Memory Impairment Identification with Mathematical Modeling of the CVLT-II Learning Curve in Multiple Sclerosis

The CVLT-II provides standardized scores for each of the List A five learning trials, so that the clinician can compare the patient's raw trials 1–5 scores with standardized ones. However, frequently, a patient's raw scores fluctuate making a proper interpretation difficult. The CVLT-II does not offer any other methods for classifying a patient's learning and memory status on the background of the learning curve. The main objective of this research is to illustrate that discriminant analysis provides an accurate assessment of the learning curve, if suitable predictor variables are selected. Normal controls were ninety-eight healthy volunteers (78 females and 20 males). A group of MS patients included 365 patients (266 females and 99 males) with clinically defined multiple sclerosis. We show that the best predictor variables are coefficients B3 and B4 of our mathematical model B3 ∗ exp(−B2  ∗  (X − 1)) + B4  ∗  (1 − exp(−B2  ∗  (X − 1))) because discriminant functions, calculated separately for B3 and B4, allow nearly 100% correct classification. These predictors allow identification of separate impairment of readiness to learn or ability to learn, or both

Update on beam-plasma interaction research at PPPL

We have performed experimental and theoretical studies of beam neutralization by background plasma. Near-complete space-charge neutralization is required for the transverse compression of highperveance ion beams for ion-beam-driven warm dense matter experiments and heavy ion fusion..

Climate Change and Inequality: How to Solve These Problems Jointly?

In recent decades, economic growth in developing economies and the growth of the middle class lead to a surge in energy consumption and greenhouse gas emissions. Within the framework of the United Nations (UN) sustainable development goals established in 2015, the solution to poverty and inequality thus comes into conflict with climate change mitigation. The existing international system of climate regulation does not address this contradiction. Today, global climate governance relies on estimates of aggregate emissions by countries without considering their level of development and the distribution of emissions among income groups within each country. Emissions from production are being monitored, while consumption-related emissions, albeit known to experts, rarely underlie decision-making. Meanwhile, income distribution has a higher impact on consumption-based emissions in comparison to production-based ones. Decisions on emissions regulation are made at the national level by countries with different development agendas in which climate change mitigation often gets less priority in comparison to other socio-economic objectives. This paper proposes a set of principles and specific mechanisms that can link climate change and inequality within a single policy framework. First, we highlight the need to modify the global emission monitoring system for the sake of accounting for emissions from consumption (rather than production) by income groups. Second, we suggest the introduction of a new redistribution system to address climate change which would include the imposition of a “fine” on households with the highest levels of emissions. Such a system follows the principles of progressive taxation but supports climate mitigation objectives and should be understood not as taxation of high incomes but rather as payment for a negative externality. Third, we outline the need to adjust climate finance criteria; priority should be given to projects designed to reduce carbon-intensive consumption by social groups entering the middle class, or to help the poorest population groups adapt to climate change. A special role in the implementation of these principles may belong to BRICS (Brazil, Russia, India, China and South Africa), which may view this as an opportunity for a proactive transition to inclusive, low-carbon development

New microfocus bremsstrahlung source based on betatron B-18 for high-resolution radiography and tomography

New microfocus source of hard bremsstrahlung (photon energy > 1 MeV), based on the betatron B-18 with a narrow Ta target inside, for high-resolution radiography and tomography is presented. The first studies of the source demonstrate its possibilities for practical applications to detect the microdefects in products made from heavy materials and to control gaps in joints of parts of composite structures of engineering facilities. The radiography method was used to investigate a compound object consisting of four vertically arranged steel bars between which surfaces were exposed gaps of 10 [mu]m in width. The radiographic image of the object, obtained with a magnification of 2.4, illustrates the good sensitivity of detecting the gaps between adjacent bars, due to the small width of the linear focus of the bremsstrahlung source

Comparative physical-tribological properties of anti-friction ion-plasma Ti-C-Mo-S coating on VT6 alloy or 20X13 and 40X steels

Results of comparative tests mechanical and tribological properties of solid antifriction Ti-C-Mo-S coating, deposited by magnetron-plasma combined sputtering method on substrates of VT6 titanium alloy, 40X and 20X13 hardened steels are provided. Coating is sputtered using the same conditions and technological regimes on substrates of different materials. However, the friction tests results showed significant difference in tribological characteristics of coating depending on type of material used for substrate, first of all by wear-resistance ability. Authors suppose that this is due to difference between physical properties such as composition and structure of substrate materials that determines hardness and coating adhesion to surface

ENHANCEMENT OF STRENGTH PROPERTIES IN BIOCOMPATIBLE Ti-Nb-Zr ALLOYS BY SEVERE PLASTIC DEFORMATION

Перспективным направлением развития производства медицинских имплантатов из биоинертных материалов является создание сплавов с низким модулем упругости, полученных методами интенсивной пластической деформации (ИПД). В исследуемых образцах из прутков плавки 92 (Ti-40Nb-5Zr) и плавки 94 (Ti-40Nb-5Zr-2Ta-2Sn) после интенсивной пластической деформации методом abc-прессования с последующей прокаткой установлено повышение предела прочности по сравнению с исходным состоянием после горячей прокатки с 620 до 940 Мпа и с 610 до 760 МПа соответственно. Изготовлен образец и методом ДМА определена зависимость модуля упругости от температуры нагрева в диапазоне от комнатной до 600 °С.A promising direction in the development of the production of medical implants made of bioinert materials is the creation of alloys with a low elastic modulus, obtained by severe plastic deformation (SPD) methods. In the studied samples from rods of melt 92 (Ti-40Nb-5Zr) and melt 94 (Ti-40Nb-5Zr-2Ta-2Sn), after severe plastic deformation by the abc-pressing method followed by rolling, an increase in ultimate strength was found compared to the initial state after hot rolling from 620 to 940 MPa and from 610 to 760 MPa, respectively. A sample was made and the dependence of the elastic modulus on the heating temperature in the range from room temperature to 600 °C was determined using the DMA method.Исследование выполнено при финансовой поддержке Министерства науки и высшего образования Российской Федерации в рамках Программы развития Уральского федерального университета имени первого Президента России Б.Н. Ельцина в соответствии с программой стратегического академического лидерства «Приоритет-2030»