The Dirichlet distribution (Dir) is one of the most widely used prior distributions in statistical approaches to natural language processing. The parameters of Dir are required to be positive, which significantly limits its strength as a sparsity prior. In this paper, we propose a simple modification to the Dirichlet distribution that allows the parameters to be negative. Our modified Dirichlet...

BACKGROUND Multiple sclerosis (MS) is a demyelinating disease of the central nervous system. MRI has an important role in early diagnosis of MS within diagnostic criteria. AIM To determine the diagnostic value of the double inversion recovery (DIR) sequence in detection of brain MS lesions. METHODS In this cross-sectional study, 55 patients were admitted to the MRI department in Vali-E-Asr ...

Link level SINR simulation results and network level sector throughput simulation results that quantify the benefit of dual antenna MMSE reception in a macrocellular HSDPA system are provided. The dual antenna RAKE receiver serves as baseline reference. Link-level simulation results are confirmed by a novel analytical expression that in flat Rayleigh fading and for uncorrelated rx antenna branc...

Purpose: Multiple sclerosis (MS) has long been considered a pure white matter (WM) disease. In recent years, greater attention is paid to cortical pathology in MS. However, detection of cortical lesions is complicated by low contrast on MRI between lesions and surrounding tissue, the relatively low image resolution, and the confounding signal from WM and cerebrospinal fluid (CSF). Double invers...

The goal of this project is to investigate quantitatively the performance of different deformable image registration algorithms (DIR) with helical (HCT), axial (ACT), and cone-beam CT (CBCT). The variations in the CT-number values and lengths of well-known targets moving with controlled motion were evaluated. Four DIR algorithms: Demons, Fast-Demons, Horn-Schunck and Lucas-Kanade were used to r...

Embryonic stem (ES) cells have great potential in applications such as disease modeling, pharmacological screening and stem cell therapies. Up to date, there is no related report on the use of ES cells as tracking and contrast reagents of cancer cells in vivo. Herein we report that DiR-labeled murine ES cells can recognize and target gastric cancer cells in vivo. DiR-labeled murine ES (mES) cel...

Introduction The use of two inversion delays with two inversion pulses allows signals with being suppressed two different tissues simultaneously, and is termed a double inversion recovery (DIR) sequence(1,2,3). Non-invasive characterizations of an effusion on the basis of imaging may obviate the need for joint aspirations with its associated patient morbidity. A fluid of the knee may consist of...

InSAR signal delays due to the varying atmospheric refractivity are a potential data source to improve weather models [1]. Especially with the launch of the new Sentinel-1 satellites, which increases data coverage, latency and accessibility, it may become possible to operationalize the assimilation of differential integrated refractivity (DIR) values in numerical weather models. Although studie...

Path Multiplexing (PM) and Link Multiplexing (LM) [3, 5] are two approaches for establishing connections (or lightpaths) in optical networks. This paper describes distributed control protocols for establishing lightpaths in WDM networks using LM and PM. We propose and evaluate the performance of two classes of protocols, namely Source Initiated Reservation (SIR) and Destination Initiated Reserv...

Introduction Most gray matter volumetric studies use T1-weighted imaging such as MP-RAGE because it provides good contrast between white matter and cortex. However, due to susceptibility artifact coming from the air-tissue interface (Fig. 1), a reliable and accurate measurement is difficult in the regions near the air-bone interface for T1-wieghted schemes. One way to alleviate this problem is ...