Artificial Intelligence

When Don Breneman called me last January to participate on the New Technologies panel, I eagerly accepted. I have a habit of eagerly accepting responsibilities that are half a year away. In June, responsibilities accepted in January have a way of causing perspiration and I don\u27t believe that has anything to do with the weather in Fargo

Constructing a Space from the System of Geodesic Equations

Given a space it is easy to obtain the system of geodesic equations on it. In this paper the inverse problem of reconstructing the space from the geodesic equations is addressed. A procedure is developed for obtaining the metric tensor from the Christoffel symbols. The procedure is extended for determining if a second order quadratically semi-linear system can be expressed as a system of geodesic equations, provided it has terms only quadratic in the first derivative apart from the second derivative term. A computer code has been developed for dealing with larger systems of geodesic equations

Conservation laws and their associated symmetries for stochastic differential equations

The modelling power of Itˆo integrals has a far reaching impact on a spectrum of diverse fields. For example, in mathematics of finance, its use has given insights into the relationship between call options and their non-deterministic underlying stock prices; in the study of blood clotting dynamics, its utility has helped provide an understanding of the behaviour of platelets in the blood stream; and in the investigation of experimental psychology, it has been used to build random fluctuations into deterministic models which model the dynamics of repetitive movements in humans. Finding the quadrature for these integrals using continuous groups or Lie groups has to take families of time indexed random variables, known as Wiener processes, into consideration. Adaptations of Sophus Lie’s work to stochastic ordinary differential equations (SODEs) have been done by Gaeta and Quintero [1], Wafo Soh and Mahomed [2], ¨Unal [3], Meleshko et al. [4], Fredericks and Mahomed [5], and Fredericks and Mahomed [6]. The seminal work [1] was extended in Gaeta [7]; the differential methodology of [2] and [3] were reconciled in [5]; and the integral methodology of [4] was corrected and reconciled in [5] via [6]. Symmetries of SODEs are analysed. This work focuses on maintaining the properties of the Weiner processes after the application of infinitesimal transformations. The determining equations for first-order SODEs are derived in an Itˆo calculus context. These determining equations are non-stochastic. Many methods of deriving Lie point-symmetries for Itˆo SODEs have surfaced. In the Itˆo calculus context both the formal and intuitive understanding of how to construct these symmetries has led to seemingly disparate results. The impact of Lie point-symmetries on the stock market, population growth and weather SODE models, for example, will not be understood until these different results are reconciled as has been attempted here. Extending the symmetry generator to include the infinitesimal transformation of the Wiener process for Itˆo stochastic differential equations (SDEs), has successfully been done in this thesis. The impact of this work leads to an intuitive understanding of the random time change formulae in the context of Lie point symmetries without having to consult much of the intense Itˆo calculus theory needed to derive it formerly (see Øksendal [8, 9]). Symmetries of nth-order SODEs are studied. The determining equations of these SODEs are derived in an Itˆo calculus context. These determining equations are not stochastic in nature. SODEs of this nature are normally used to model nature (e.g. earthquakes) or for testing the safety and reliability of models in construction engineering when looking at the impact of random perturbations. The symmetries of high-order multi-dimensional SODEs are found using form invariance arguments on both the instantaneous drift and diffusion properties of the SODEs. We then apply this to a generalised approximation analysis algorithm. The determining equations of SODEs are derived in an It¨o calculus context. A methodology for constructing conserved quantities with Lie symmetry infinitesimals in an Itˆo integral context is pursued as well. The basis of this construction relies on Lie bracket relations on both the instantaneous drift and diffusion operators

News Releases Delivered by Computer

An electronic information transfer system, called Michigan State University Information Services (MSUIFS), can store and deliver news and feature stories to mass media outlets and to Michigan county Extension offices

Early affective changes and increased connectivity in preclinical Alzheimer's disease.

IntroductionAffective changes precede cognitive decline in mild Alzheimer's disease and may relate to increased connectivity in a "salience network" attuned to emotionally significant stimuli. The trajectory of affective changes in preclinical Alzheimer's disease, and its relationship to this network, is unknown.MethodsOne hundred one cognitively normal older adults received longitudinal assessments of affective symptoms, then amyloid-PET. We hypothesized amyloid-positive individuals would show enhanced emotional reactivity associated with salience network connectivity. We tested whether increased global connectivity in key regions significantly related to affective changes.ResultsIn participants later found to be amyloid positive, emotional reactivity increased with age, and interpersonal warmth declined in women. These individuals showed higher global connectivity within the right insula and superior temporal sulcus; higher superior temporal sulcus connectivity predicted increasing emotional reactivity and decreasing interpersonal warmth.ConclusionsAffective changes should be considered an early preclinical feature of Alzheimer's disease. These changes may relate to higher functional connectivity in regions critical for social-emotional processing

Prenatal aromatase inhibition alters postnatal immunity in domestic chickens (Gallus gallus)

In birds, exposure to exogenous testosterone during embryonic development can suppress measures of immune function; however, it is unclear whether these effects are due to direct or indirect action via aromatization. Estradiol (E2) is synthesized from testosterone by the enzyme aromatase, and this conversion is a necessary step in many signaling pathways that are ostensibly testosterone-dependent. Many lines of evidence in mammals indicate that E2 can affect immune function. We tested the hypothesis that some of the immunomodulatory effects observed in response to in ovo testosterone exposure in birds are mediated by conversion to E2 by aromatase, by using fadrozole to inhibit aromatization of endogenous testosterone during a crucial period of embryonic immune system development in domestic chickens (Gallus gallus). We then measured total IgY antibody count, response to PHA challenge, mass of thymus and bursa of Fabricius, and plasma testosterone post-hatch on days 3 and 18. Because testosterone has a reputation for immunosuppression, we predicted that if modulation of an immune measure by testosterone is dependent on aromatization, then inhibition of estrogen production by fadrozole treatment would lead to elevated measures of that parameter. Conversely, if testosterone inhibits an immune measure directly, then fadrozole treatment would likely not alter that parameter. Fadrozole treatment reduced circulating E2 in female embryos, but had no effect on males or on testosterone in either sex. Fadrozole-treated chicks had decreased day 3 plasma IgY antibody titers and a strong trend towards increased day 18 thymic mass. Furthermore, fadrozole treatment generated a positive relationship between testosterone and thymic mass in males, and tended to increase day 18 IgY levels for a given bursal mass in females. There was no effect on PHA response, bursal mass, or plasma testosterone at either age post-hatch. The alteration of several indicators of immune function in fadrozole-treated chicks implicates aromatization as a relevant pathway through which developmental exposure to testosterone can affect immunity in bird

Learning in an Introductory Physics MOOC: All Cohorts Learn Equally, Including an On-Campus Class

We studied student learning in the MOOC 8.MReV Mechanics ReView, run on the edX.org open source platform. We studied learning in two ways. We administered 13 conceptual questions both before and after instruction, analyzing the results using standard techniques for pre- and posttesting. We also analyzed each week’s homework and test questions in the MOOC, including the pre- and posttests, using item response theory (IRT). This determined both an average ability and a relative improvement in ability over the course. The pre- and posttesting showed substantial learning: The students had a normalized gain slightly higher than typical values for a traditional course, but significantly lower than typical values for courses using interactive engagement pedagogy. Importantly, both the normalized gain and the IRT analysis of pre- and posttests showed that learning was the same for different cohorts selected on various criteria: level of education, preparation in math and physics, and overall ability in the course. We found a small positive correlation between relative improvement and prior educational attainment. We also compared homework performance of MIT freshmen taking a reformed on-campus course with the 8.MReV students, finding them to be considerably less skillful than the 8.MReV students.Google (Firm) (Faculty Award)Massachusetts Institute of TechnologyNational Science Foundation (U.S.

A systematic review of parent and family functioning in pediatric solid organ transplant populations

The process of pediatric solid organ transplantation (SOT) places new and increased stressors on patients and family members. Measures of family functioning may predict psychological and health outcomes for pediatric patients and their families, and provide opportunity for targeted intervention. This systematic review investigated parent and family functioning and factors associated with poorer functioning in the pediatric SOT population. Thirty‐seven studies were identified and reviewed. Studies featured a range of organ populations (eg, heart, liver, kidney, lung, intestine) at various stages in the transplant process. Findings highlighted that parents of pediatric SOT populations commonly report increased stress and mental health symptoms, including posttraumatic stress disorder. Pediatric SOT is also associated with increased family stress and burden throughout the transplant process. Measures of parent and family functioning were associated with several important health‐related factors, such as medication adherence, readiness for discharge, and number of hospitalizations. Overall, findings suggest that family stress and burden persists post‐transplant, and parent and family functioning is associated with health‐related factors in SOT, highlighting family‐level functioning as an important target for future intervention.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136483/1/petr12900.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136483/2/petr12900_am.pd