The neural economics of brain aging

Despite remarkable advances, research into neurodegeneration and Alzheimer Disease (AD) has nonetheless been dominated by inconsistent and conflicting theory. Basic questions regarding how and why the brain changes over time remain unanswered. In this work, we lay novel foundations for a consistent, integrated view of the aging brain. We develop neural economics—the study of the brain’s infrastructure, brain capital. Using mathematical modeling, we create ABC (Aging Brain Capital), a simple linear simultaneous-equation model that unites aspects of neuroscience, economics, and thermodynamics to explain the rise and fall of brain capital, and thus function, over the human lifespan. Solving and simulating this model, we show that in each of us, the resource budget constraints of our finite brains cause brain capital to reach an upper limit. The thermodynamics of our working brains cause persistent pathologies to inevitably accumulate. With time, the brain becomes damaged causing brain capital to depreciate and decline. Using derivative models, we suggest that this endogenous aging process underpins the pathogenesis and spectrum of neurodegenerative disease. We develop amyloid–tau interaction theory, a paradigm that bridges the unnecessary conflict between amyloid- and tau-centered hypotheses of AD. Finally, we discuss profound implications for therapeutic strategy and development.

Improving " Jackknife Instrumental Variable Estimation method" using A class of immun algorithm with practical application

Most of the robust methods based on the idea of ​​sacrificing one side versus promotion of another, the artificial intelligence mechanisms try to balance weakness and strength to make the best solutions in a random search technique. In this paper, a new idea is introduced to improve the estimators of parameters of linear simultaneous equation models that resulting from the Jackknife Instrumental Variable Estimation method (JIVE) by using a class of immune algorithm which called Clonal Selection Algorithm (CSA) and better estimates are obtained using one of the robust criterion which is called Mean Absolut Percentage Error (MAPE). The success of intelligence algorithm mechanisms has been proven that used to improve the parameters of linear simultaneous equation models according to user criterion and real data of size n=48.

ANALISIS PERSAMAAN SIMULTAN DARI TOBIN’S Q, KEPEMILIKAN MANAJERIAL DAN KEBIJAKAN UTANG

The purpose of this research to estimates a simultaneous equations model with Tobin’s Q (firm value), managerial ownership and debt policy jointly determined within the system. This research is based on the pre¬vious¬ research by Chen and Steiner (2000), which found that managerial ownership tobe a significant and positive determinant of the level Tobin’s Q. Chen and Steiner (1999) observed evidence of subtituons-monitoring effects between managerial ownership and debt policy.The research is focused on manufacturing companies listed in BEJ for periode 1999-2002.The method of data collection is done by using pooling method and give 151 firm year observation.This research uses a non linear simultaneous equation methodology with use the statistical method two stage least square. The result of research provides empirical evidence : First, that managerial ownership has a non linear relation with Tobin’s Q (we find support for both an alignmenteffect and an entrenchment effectin the relationship between managerial ownership and Tobin’s Q. second, The result supports the argument that managerial ownership helps to resolve the agency conflicts between stock holder and manager. The result also indicate that there is not subtitu¬ta¬bi¬li¬ty between debt and managerial ownership.

تطبيق طريقة "LIML_LVR" عمليا وفق صيغة K-CLASS العامة على منظومة معادلات آنية مقترحة *

In this paper we try to shed light on one of the methods of estimating the structural parameters of the linear simultaneous equations models Which provide consistent estimates sometimes differ from those that we get from other traditional methods according to the estimators of the general formula K-CLASS .This method is known as the limited information maximum likelihood "LIML" or least variance ratio "LVR" method, which represent by formula (14.2) The other side of the LIML method, which is famous for estimating parameters in linear simultaneous equation (individually) attributed to the system of linear equations so that the identification test for this type of equation be over identified and the advantage of this method in the general formula for the estimators of K-CLASS That the value of k be a variable otherwise known other estimators of K-CLASS in which the value of k is a constant Where the method has been applied to simple real-time system of linear equations constructed by the researcher describe the relationship between economic growth, exports and some variables related to them and draw conclusions using ready-made programs (Excel, Minitab) and finally to comment on the results and viewing the main conclusions and then write some of the recommendations.

ANALISIS PERSAMAAN SIMULTAN DARI TOBIN’S Q, KEPEMILIKAN MANAJERIAL DAN KEBIJAKAN UTANG

The purpose of this research to estimates a simultaneous equations model with Tobin’s Q (firm value), managerial ownership and debt policy jointly determined within the system. This research is based on the pre¬vious¬ research by Chen and Steiner (2000), which found that managerial ownership tobe a significant and positive determinant of the level Tobin’s Q. Chen and Steiner (1999) observed evidence of subtituons-monitoring effects between managerial ownership and debt policy.The research is focused on manufacturing companies listed in BEJ for periode 1999-2002.The method of data collection is done by using pooling method and give 151 firm year observation.This research uses a non linear simultaneous equation methodology with use the statistical method two stage least square. The result of research provides empirical evidence : First, that managerial ownership has a non linear relation with Tobin’s Q (we find support for both an alignmenteffect and an entrenchment effectin the relationship between managerial ownership and Tobin’s Q. second, The result supports the argument that managerial ownership helps to resolve the agency conflicts between stock holder and manager. The result also indicate that there is not subtitu¬ta¬bi¬li¬ty between debt and managerial ownership.

RELATIVE STUDY OF SOLVERS FOR FINITE ELEMENT ANALYSIS

A relative study of various linear simultaneous equation solvers has been made. The profile solver and the block solver which have been considered to be most effective solution techniques have been implemented. Medium to large sized structural analysis problems have been analyzed. The comparison of solution time, total execution time and the incore memory requirement have been made. The suitability of solvers for various sized problems has also been discussed.

ESTIMATING A LINEAR SIMULTANEOUS EQUATION MODEL WITH PANEL DATA

In this paper we consider a class of the GMM estimators for a linear simultaneous equation model with panel data. The model is characterized by the presence of unobserved individual effects as part of structural disturbances and by the correlation of certain time-varying and time-invariant exogenous variables with the individual effects. A class of single-equation and system GMM estimators is proposed on the basis of a class of instruments as a unifying theme. Small-sample performance of this class of estimators is also investigated by a series of sampling experiments.