Estimating the confidence level of white matter connections obtained with MRI tractography.

BACKGROUND: Since the emergence of diffusion tensor imaging, a lot of work has been done to better understand the properties of diffusion MRI tractography. However, the validation of the reconstructed fiber connections remains problematic in many respects. For example, it is difficult to assess whether a connection is the result of the diffusion coherence contrast itself or the simple result of other uncontrolled parameters like for example: noise, brain geometry and algorithmic characteristics. METHODOLOGY/PRINCIPAL FINDINGS: In this work, we propose a method to estimate the respective contributions of diffusion coherence versus other effects to a tractography result by comparing data sets with and without diffusion coherence contrast. We use this methodology to assign a confidence level to every gray matter to gray matter connection and add this new information directly in the connectivity matrix. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that whereas we can have a strong confidence in mid- and long-range connections obtained by a tractography experiment, it is difficult to distinguish between short connections traced due to diffusion coherence contrast from those produced by chance due to the other uncontrolled factors of the tractography methodology.

Ultrastructural study of the pit connections of Gelidiocolax Gardner (parasitic Rhodophyta)

A report on the ultrastructural observations of the pit connections in three species of Gelidiocolax (G. margarifoides (Martin and Pocock) Fan and Papenfus, G. christianae Feldmann and G. deformans Seoane-Carnba) has been carried out. As has been described in other species, electrondense elements and myelinic figures, possibly formed by the endoplasmic reticulum, were condensed in a mass. This mass became a diabolos-shaped structure before the cytoplasm had finished its division and the septum had reached its complete development. Myelinic figures were usually found in the core of well formed pit plugs, but such figures were apparently substituted by granular material during the ontogeny. Key words: Gelidiocolax ultrastructure, Pit connection, Pit connection ultrastructure, Pit connection Ontogeny.

On the relationship between connections and the asymptotic properties of predictive distributions

In a recent paper, Komaki studied the second-order asymptotic properties of predictive distributions, using the Kullback-Leibler divergence as a loss function. He showed that estimative distributions with asymptotically efficient estimators can be improved by predictive distributions that do not belong to the model. The model is assumed to be a multidimensional curved exponential family. In this paper we generalize the result assuming as a loss function any f divergence. A relationship arises between alpha connections and optimal predictive distributions. In particular, using an alpha divergence to measure the goodness of a predictive distribution, the optimal shift of the estimate distribution is related to alpha-covariant derivatives. The expression that we obtain for the asymptotic risk is also useful to study the higher-order asymptotic properties of an estimator, in the mentioned class of loss functions.

Chronic Disease Connections, December 2013

IDPH has a new grant-funded program, the Health Promotion and Chronic Disease Control Partnership. This publication, Chronic Disease Connections, will be part of the communication strategy between IDPH staff and healthcare system providers throughout the state as we partner to help patients control their diabetes and high blood pressure. This is just one of the major objectives for the funding. The CDC would like to see that more patients are aware that they have pre-diabetes, diabetes or high blood pressure and that health systems are maximizing evidence-based strategies to assist patients with achieving control. Over the coming months you will hear more about the new program and how you can become involved.

Iowa connections : get on board with passenger rail!

Iowa's rail network offers a great opportunity for passenger rail service, connecting Iowa's largest urban areas to Chicago and potential other Midwest metropolitan centers. The Iowa Department of Transportation (DOT), working with the state of Illinois, Iowa cities, planning organizations and advocacy groups, has created a bold new vision called Iowa Connections. The vision will create a passenger rail network that connects Iowans to each other and the country, and makes Iowa a more attractive place to live, work and visit.

Preventing Cracking at Diaphragm/Plate Girder Connections in Steel Bridges, HR-393, 1998

Some of the Iowa Department of Transportation (Iowa DOT) continuous, steel, welded plate girder bridges have developed web cracking in the negative moment regions at the diaphragm connection plates. The cracks are due to out-of-plane bending of the web near the top flange of the girder. The out-of-plane bending occurs in the "web-gap", which is the portion of the girder web between (1) the top of the fillet welds attaching the diaphragm connection plate to the web and (2) the fillet welds attaching the flange to the web. A literature search indicated that four retrofit techniques have been suggested by other researchers to prevent or control this type of cracking. To eliminate the problem in new bridges, AASHTO specifications require a positive attachment between the connection plate and the top (tension) flange. Applying this requirement to existing bridges is expensive and difficult. The Iowa DOT has relied primarily on the hole-drilling technique to prevent crack extension once cracking has occurred; however, the literature indicates that hole-drilling alone may not be entirely effective in preventing crack extension. The objective of this research was to investigate experimentally a method proposed by the Iowa DOT to prevent cracking at the diaphragm/plate girder connection in steel bridges with X-type or K-type diaphragms. The method consists of loosening the bolts at some connections between the diaphragm diagonals and the connection plates. The investigation included selecting and testing five bridges: three with X-type diaphragms and two with K-type diaphragms. During 1996 and 1997, these bridges were instrumented using strain gages and displacement transducers to obtain the response at various locations before and after implementing the method. Bridges were subjected to loaded test trucks traveling in different lanes with speeds varying from crawl speed to 65 mph (104 km/h) to determine the effectiveness of the proposed method. The results of the study show that the effect of out-of-plane loading was confined to widths of approximately 4 in. (100 mm) on either side of the connection plates. Further, they demonstrate that the stresses in gaps with drilled holes were higher than those in gaps without cracks, implying that the drilling hole technique is not sufficient to prevent crack extension. The behavior of the web gaps in X-type diaphragm bridges was greatly enhanced by the proposed method as the stress range and out-of-plane distortion were reduced by at least 42% at the exterior girders. For bridges with K-type diaphragms, a similar trend was obtained. However, the stress range increased in one of the web gaps after implementing the proposed method. Other design aspects (wind, stability of compression flange, and lateral distribution of loads) must be considered when deciding whether to adopt the proposed method. Considering the results of this investigation, the proposed method can be implemented for X-type diaphragm bridges. Further research is recommended for K-type diaphragm bridges.

Chronic Disease Connections, January 2014

IDPH has a new grant-funded program, the Health Promotion and Chronic Disease Control Partnership. This publication, Chronic Disease Connections, will be part of the communication strategy between IDPH staff and healthcare system providers throughout the state as we partner to help patients control their diabetes and high blood pressure. This is just one of the major objectives for the funding. The CDC would like to see that more patients are aware that they have pre-diabetes, diabetes or high blood pressure and that health systems are maximizing evidence-based strategies to assist patients with achieving control. Over the coming months you will hear more about the new program and how you can become involved.

Chronic Disease Connections, February 2014

IDPH has a new grant-funded program, the Health Promotion and Chronic Disease Control Partnership. This publication, Chronic Disease Connections, will be part of the communication strategy between IDPH staff and healthcare system providers throughout the state as we partner to help patients control their diabetes and high blood pressure. This is just one of the major objectives for the funding. The CDC would like to see that more patients are aware that they have pre-diabetes, diabetes or high blood pressure and that health systems are maximizing evidence-based strategies to assist patients with achieving control. Over the coming months you will hear more about the new program and how you can become involved.

Chronic Disease Connections, March 2014

IDPH has a new grant-funded program, the Health Promotion and Chronic Disease Control Partnership. This publication, Chronic Disease Connections, will be part of the communication strategy between IDPH staff and healthcare system providers throughout the state as we partner to help patients control their diabetes and high blood pressure. This is just one of the major objectives for the funding. The CDC would like to see that more patients are aware that they have pre-diabetes, diabetes or high blood pressure and that health systems are maximizing evidence-based strategies to assist patients with achieving control. Over the coming months you will hear more about the new program and how you can become involved.

Chronic Disease Connections, April 2014

IDPH has a new grant-funded program, the Health Promotion and Chronic Disease Control Partnership. This publication, Chronic Disease Connections, will be part of the communication strategy between IDPH staff and healthcare system providers throughout the state as we partner to help patients control their diabetes and high blood pressure. This is just one of the major objectives for the funding. The CDC would like to see that more patients are aware that they have pre-diabetes, diabetes or high blood pressure and that health systems are maximizing evidence-based strategies to assist patients with achieving control. Over the coming months you will hear more about the new program and how you can become involved.

Chronic Disease Connections, May 2014

IDPH has a new grant-funded program, the Health Promotion and Chronic Disease Control Partnership. This publication, Chronic Disease Connections, will be part of the communication strategy between IDPH staff and healthcare system providers throughout the state as we partner to help patients control their diabetes and high blood pressure. This is just one of the major objectives for the funding. The CDC would like to see that more patients are aware that they have pre-diabetes, diabetes or high blood pressure and that health systems are maximizing evidence-based strategies to assist patients with achieving control. Over the coming months you will hear more about the new program and how you can become involved.

Chronic Disease Connections, June 2014

IDPH has a new grant-funded program, the Health Promotion and Chronic Disease Control Partnership. This publication, Chronic Disease Connections, will be part of the communication strategy between IDPH staff and healthcare system providers throughout the state as we partner to help patients control their diabetes and high blood pressure. This is just one of the major objectives for the funding. The CDC would like to see that more patients are aware that they have pre-diabetes, diabetes or high blood pressure and that health systems are maximizing evidence-based strategies to assist patients with achieving control. Over the coming months you will hear more about the new program and how you can become involved.

Chronic Disease Connections, July 2014

IDPH has a new grant-funded program, the Health Promotion and Chronic Disease Control Partnership. This publication, Chronic Disease Connections, will be part of the communication strategy between IDPH staff and healthcare system providers throughout the state as we partner to help patients control their diabetes and high blood pressure. This is just one of the major objectives for the funding. The CDC would like to see that more patients are aware that they have pre-diabetes, diabetes or high blood pressure and that health systems are maximizing evidence-based strategies to assist patients with achieving control. Over the coming months you will hear more about the new program and how you can become involved.

Chronic Disease Connections, September 2014

IDPH has a new grant-funded program, the Health Promotion and Chronic Disease Control Partnership. This publication, Chronic Disease Connections, will be part of the communication strategy between IDPH staff and healthcare system providers throughout the state as we partner to help patients control their diabetes and high blood pressure. This is just one of the major objectives for the funding. The CDC would like to see that more patients are aware that they have pre-diabetes, diabetes or high blood pressure and that health systems are maximizing evidence-based strategies to assist patients with achieving control. Over the coming months you will hear more about the new program and how you can become involved.