Football Concussions: Effects, Evaluation and Prevention

Football related concussions are a growing concern in society. Concussions can lead to a major brain disease called chronic traumatic encephalopathy. This disease leads to many degenerative qualities that affect physical, cognitive, and emotional aspects in football players. In this review, the effects, evaluation, and prevention of concussions in football are discussed. Concussion rates and brain damage can both be decreased through improving equipment such as helmet design as well as better head-on collision rules being developed, and better evaluation techniques for taking concussed players out of games. In the future, with the combination of advancements in evaluation and prevention, concussions can start to become less of a concern

Stability of fixed points in Poisson geometry and higher Lie theory

We provide a uniform approach to obtain sufficient criteria for a (higher order) fixed point of a given bracket structure on a manifold to be stable under deformations. Examples of bracket structures include Lie algebroids, Lie $n$-algebroids, singular foliations, Lie bialgebroids, Courant algebroids and Dirac structures in split Courant algebroids admitting a Dirac complement. We show that the stability problems are specific instances of the following problem: given a differential graded Lie algebra $\mathfrak g$, a differential graded Lie subalgebra $\mathfrak h$ of degreewise finite codimension in $\mathfrak g$ and a Maurer-Cartan element $Q\in \mathfrak h^1$, when are Maurer-Cartan elements near $Q$ in $\mathfrak g$ gauge equivalent to elements of $\mathfrak h^1$? We show that the vanishing of a finite-dimensional cohomology group associated to $\mathfrak g,\mathfrak h$ and $Q$ implies a positive answer to the question above, and therefore implies stability of fixed points of the geometric structures described above. In particular, we recover the stability results of Crainic-Fernandes for zero-dimensional leaves, as well as the stability results for higher order singularities of Dufour-Wade.Comment: 58 page

Thousand Cankers Disease: Virulence of \u3ci\u3eGeosmithia morbida\u3c/i\u3e isolates and potential alternative vectors of the fungus

The fungal pathogen, Geosmithia morbida, along with its vector, walnut twig beetle (WTB), Pityophthorus juglandis is the causal agent of the Thousand Cankers Disease complex (TCD) in Juglans spp. and Pterocarya spp. Disease outbreaks have been reported in the eastern and western United States (U.S.). Since TCD was detected in the western U.S. in early 2000s, the disease complex has spread to the eastern U.S. and Italy, Europe. In our preliminary data, G. morbida isolates from eastern and western states have been placed in five distinct genetic clusters, though geography was not correlated with origins of isolates of each cluster. In the eastern U.S., fungal pathogen had been detected on other insect species besides WTB. These insect species included two ambrosia beetles, Xyleborinus saxesenii and Xylosandrus crassiusculus, and a bark weevil, Stenomimus pallidus. Since TCD incidence and severity have been reported to be higher in the western U.S. states when compared to the eastern states, we hypothesized that differences in disease severity and incidence are due to variations in the fungal virulence at different geographical locations. To test our hypothesis, the proposed study had two specific objectives: 1) to determine if other wood boring beetle species could be potential vectors of G. morbida in Tennessee, and 2) to evaluate the level of virulence of five isolates from each of the five genetically distinct clusters of G. morbida. Our results indicated that eleven species of bark and ambrosia beetles were found to carry G. morbida. This finding raised concerns about the role these potential vector species play in the dissemination of the pathogen to healthy walnut trees. We also found that canker area was not correlated with geography or genetic clusters. The genetic Cluster 1 produced significantly larger cankers with the mean canker area 271 mm2 (millimeter square) than isolates from the four other clusters. In addition, isolates from the same genetic cluster exhibited significant variation in virulence. In conclusion, results from this study present potential implications to phytosanitary and quarantine efforts of TCD

Statistical modelling and analysis of traffic: a dynamic approach

In both developed and emerging-economies, major cities continue to experience increasing traffic congestion. To address this issue, complex Traffic Management Systems (TMS) are employed in recent years to help manage traffic. These systems fuse traffic-surveillance-related information from a variety of sensors deployed across traffic networks. A TMS requires real-time information to make effective control decisions and to deliver trustworthy information to users, such as travel time, congestion level, etc. There are three fundamental inputs required by TMS, namely, traffic volume, vehicular speed, and traffic density. Using conventional traffic loop detectors one can directly measure flow and velocity. However, traffic density is more difficult to measure. The situation becomes more difficult for multi-lane motorways due to drivers lane-change behaviour. This research investigates statistical modelling and analysis of traffic flow. It contributes to the literature of transportation and traffic management and research in several aspects. First, it takes into account lane-changes in traffic modelling through incorporating a Markov chain model to describe the drivers lane-change behaviour. Secondly, the lane change probabilities between two adjacent lanes are not assumed to be fixed but rather they depend on the current traffic condition. A discrete choice model is used to capture drivers lane choice behaviour. The drivers choice probabilities are modelled by several traffic-condition related attributes such as vehicle time headway, traffic density and speed. This results in a highly nonlinear state equation for traffic density. To address the issue of high nonlinearity of the state space model, the EKF and UKF is used to estimate the traffic density recursively. In addition, a new transformation approach has been proposed to transform the observation equation from a nonlinear form to a linear one so that the potential approximation in the EKF & UKF can be avoided. Numerical studies have been conducted to investigate the performance of the developed method. The proposed method outperformed the existing methods for traffic density estimation in simulation studies. Furthermore, it is shown that the computational cost for updating the estimate of traffic densities for a multi-lane motorway is kept at a minimum so that online applications are feasible in practice. Consequently the traffic densities can be monitored and the relevant information can be fed into the traffic management system of interest

Antenatal diagnosis of omphalocele and spinal dysraphism: a possible OEIS complex

OEIS complex, which comprises of omphalocele, exstrophy bladder, imperforate anus and spinal dysraphism, is a rare disorder. The prognosis depends upon the severity of the structural defects. Survival depends on the extension of the cloacal exstrophy and the neural tube defect. The antenatal diagnosis in early pregnancy is very tough, and a high level of suspicion should be kept for the possibility of its existence, even only if omphalocele and spinal dysraphism are seen on a prenatal sonography. Authors present the case of a 33-year-old, G1P0 female, who on her prenatal routine sonography scan, was found to have a fetus with omphalocele and spinal dysraphism. Despite the repeated attempts to follow her up, she refused and hence the possibility of the presence of other associated malformations could not be ascertained. Considering the difficulty of antenatal diagnosis of OEIS complex and its associated mortality, the objective of this case report is to discuss the vital sonographic findings of OEIS, along with its etiology and prognosis, which can aid in its early detection and subsequently help parents to make a decision regarding the continuation of pregnancy

Antenatal diagnosis of alobar holoprosencephaly

Holoprosencephaly (HPE), a congenital induction disorder, occurs due to failed segmentation of neural tube and subsequent incomplete separation of the prosencephalon. Because of the defect in the ventral induction, HPE is also associated with multiple facial abnormalities. Mortality correlates with the severity of brain malformation and facial phenotype. Frequent causes of death include respiratory infections, dehydration due to uncontrolled diabetes insipidus, intractable seizures, and brainstem malfunction. This is a case of Alobar holoprosencephaly in the fetus of a 31-year-old G2P1 female, detected on level II obstetric ultrasound at 17 weeks of gestation. The objective of this case report is to discuss the etiology, pathogenesis, prenatal sonographic findings, management and prognosis of HPE which can aid in its early antenatal diagnosis and can help formulate an adequate plan for the parents and fetus

Stability of fixed points of Dirac structures

Given an $L_{\infty}$-algebra $V$ and an $L_{\infty}$-subalgebra $W$, we give sufficient conditions for all small Maurer-Cartan elements of $V$ to be equivalent to Maurer-Cartan elements lying in $W$. As an application, we obtain a stability criterion for fixed points of a Dirac structure (for instance a twisted Poisson structure), i.e. points where the corresponding leaf is zero-dimensional. The criterion guarantees that any nearby Dirac structure also has a fixed point.Comment: 22 page