Morphology and volatile compounds of metathoracic scent gland in Tessaratoma papillosa (Drury) (Hemiptera: Tessaratomidae)

Tessaratoma papillosa (Drury) (Hemiptera: Tessaratomidae) is a serious insect pest of litchi and longan in South China. When disturbed, this insect could release large quantities of disagreeable odorous volatiles from its scent gland. Knowledge on the scent gland and its secretion is crucial for developing the semiochemical methods to manage this pest. Morphology and ultrastructure of the metathoracic scent glands (MTGs) were studied under stereo and scanning electron microscopy, and the volatile compounds of MTGs from both male and female T. papillosa were analyzed with coupled gas chromatography-mass spectrometry (GC-MS). The MTG complex is located between the metathorax and the first abdominal segment at the ventral surface of the insect, which has a well-developed single double valve cystic-shaped orange median reservoir, paired colorless lateral glands in both sides, and a long and wavy tubular accessory gland that inlays tightly into the ventral edge around the median reservoir. The MTG opens to the body surface through paired ostioles located between the meso- and metacoxae of the evaporatorium with mushroom bodies. The GC-MS analyses showed that female and male adults have nine major volatile components in common. Tridecane is the most abundant in both females and males, reaching up to 47.1% and 51.8% of relative amount, respectively. The minor component is benzophenone with only 0.28% and 0.14%. Furthermore, undecane, tetradecane, 3-methyl-tridecane, and cyclopentadecane were found only in males. The possible function of volatile compounds of MTG contents in T. papillosa is addressed.

Post-stroke wrist rehabilitation assisted with an intention-driven functional electrical stimulation (FES)-robot system

In this work, a novel FES-robot system was developed for wrist rehabilitation training after stroke. The FES-robot system could be continuously controlled by electromyography (EMG) from the residual wrist muscles to facilitate wrist flexion and extension tracking tasks on a horizontal plane by providing assistance from both FES and robot parts. The system performance with five different assistive combinations from the FES and robot parts was evaluated by subjects with chronic stroke (n=5). The results suggested that the assistance from the robot part mainly improved the movement accuracy in the tracking tasks; and the assistance from the FES part mainly suppressed the excessive muscular activities from the elbow joint. The best combination was when the assistances from FES and robot was 1:1, and the results showed better wrist tracking performance with less muscle co-contraction from the elbow joint.

Alterations of directional connectivity among resting-state networks in Alzheimer disease

BACKGROUND AND PURPOSE

AD has been documented as a kind of disconnection syndrome by functional neuroimaging studies. The primary focus of this study was to examine, with the use of resting-state fMRI, whether AD would impact connectivity among RSNs.

MATERIALS AND METHODS

Fourteen patients with AD and 16 NC were recruited and scanned by using resting-state fMRI. Group independent-component analysis and the BN learning approach were used, respectively, to separate the RSNs and construct the network-to-network connectivity patterns for each group. The convergence index for the special network DMN was measured.

RESULTS

Three of the 4 connections were significantly lower in AD compared with NC. Although numerically the AD group had more connections, none was statistically different from that in the NC group except for 1 increased connection from the DMN to the DAN. The convergence index for the DMN node was lower in AD than in NC.

CONCLUSIONS

Connections among cognitive networks in AD were more vulnerable to impairment than sensory networks. The DMN decreased its integration function for other RSNs but may also play a role in compensating for the disrupted connections in AD.

Regulation of Olig2 during astroglial differentiation in the subventricular zone of a cuprizone-induced demyelination mouse model

The mammalian subventricular zone (SVZ) is the largest germinative zone of the adult brain. Progenitor cells generated from the SVZ play important roles during the remyelination process. To determine the functional role of Olig2 in regulating astroglial differentiation in the mouse SVZ, we used the cuprizone mouse model to investigate demyelination. We found that cuprizone administration significantly enhanced the expression of Olig2 and increased astroglial differentiation in the SVZ, as compared with control. Moreover, cytoplasmic translocation of Olig2 occurred after demyelination. In vitro studies further revealed that supplementation of culture media with growth factors enhanced the oligodendroglial differentiation of oligodendrocyte progenitor cells (OPCs), whereas serum alone promoted astroglial differentiation and cytoplasmic translocation of Olig2. Additionally, the expression levels of bone morphogenetic proteins 2 and 4 (BMP2 and BMP4) and inhibitor of DNA binding 2 and 4 (Id2 and Id4) were greatly elevated during astroglial differentiation. BMP inhibition by noggin suppressed the astroglial differentiation of OPCs. Our results indicate that Olig2 may serve as a key regulator during the directional differentiation of progenitor cells after demyelination. The BMP signaling pathway may contribute to the cytoplasmic translocation and altered expression of Olig2 during the remyelination process. These findings provide a better understanding of the mechanisms involved in remyelination.

WE-C-217BCD-05: A Novel Interpolation Method for the 3D Reconstruction of Cell Structures

PURPOSE

To develop a new interpolation method for accurate 3D reconstruction of cell morphology from laser scanning confocal microscope (LSCM) image data.

METHODS

Current techniques are based on the assumption that pixel intensity or contour shapes of images change linearly in the interpolation direction. Gray-value and position of the pixel in interpolated image slice are obtained through weighted average calculation with gray-values and distances of corresponding pixels in two adjacent original image slices, only information from adjacent image slices is considered, often fail to meet the need of 3D reconstruction for cells because of the complex cell morphology. The new method interpolates cellular organelle contours in polar coordinate system. Coordinate system origin is chosen to be the mass center weighted by pixel intensity instead of conventional geometric center, contour points of the organelle is sampled by their angles first and fitted with uniform cubic B-spline to perform interpolation. For complex organelle structures such as branched nuclei, a special method combining morphological information and corner detection technique based on curvature scale space has been developed to solve the contour division and related problems. New method was applied to confocal images of 130 different cells acquired with an LSCM system (LSM510, Zeiss), sampling step was set as 0.5 μm in longitudinal direction, pixel size in horizontal plane was 0.07 μm and the resolution was 512×512. Marching cubes algorithm was used for 3D reconstruction.

RESULTS

Experiments showed that reconstructed 3D images with new method have much smoother and more valid organelle surfaces for both cytoplasm and nucleus than those from conventional methods.

CONCLUSIONS

The new interpolation method can significantly improve the quality of 3D reconstruction and serve as a valid and effective tool for quantitative study of 3D cell morphology in radiation biology and other areas of life science.*support by NSFC- 81171342. Supported by the National Science Foundation of China (NSFC- 81171342).

SU-D-BRA-01: Accurate Real-Time Tumor Motion Estimation from Respiratory Surrogates via Memory-Based Learning

PURPOSE

Respiratory tumor motion is a major challenge in radiation therapy. Effective beam gating or tracking approaches necessitate an accurate knowledge of the real-time tumor motion. Fluoroscopic tracking with implanted fiducial markers is invasive and exposes the patient to additional imaging dose. Respiratory surrogate signal measured by external noninvasive and non-ionizing devices provides an attractive approach, in which estimating the tumor motion from respiratory surrogates is crucial.

METHODS

We utilize a powerful memory-based learning approach to find the complex relations between tumor motion and respiratory surrogates. The learning method uses locally weighted functions to interpolate between and extrapolate from training data. Due to the local nature of the learning functions, it is inherently robust to outliers. Moreover, both training and adapting to new data is highly efficient and almost free, making it suitable for dynamically following possibly variable internal/external relations. We evaluated the method using respiratory motion data (3D tumor motion plus 1D surrogate) from six patients (three lung and three pancreas patients).

RESULTS

Given only 5-sec (roughly one breath) pretreatment training data, the method achieved an average 3D error of 0.37 mm (range: 0.10 mm - 1.06 mm) and 95th percentile error of 0.86 mm (range: 0.24 mm - 2.47 mm) on 120-sec unseen test data. These errors are well below the average peak- to-peak amplitude (-10 mm). The errors decrease monotonically with an increasing amount of training data. Compared with the best linear model, the learning approach achieved a 21% reduction in error for an average patient (range: 10% - 42%).

CONCLUSIONS

The memory-based learning technique is able to accurately capture the highly nonlinear and complex relations between tumor and surrogate motion in an efficient manner (∼1 ms per prediction). These desirable properties make it an ideal candidate for accurate and robust tumor gating/tracking using respiratory surrogates.

Ten year survival and outcomes in a prospective cohort of new onset Chinese Parkinson's disease patients

OBJECTIVE

The 10 year outcomes and impact of motor and non-motor features on survival of a cohort of new onset Chinese Parkinson's disease (PD) patients were prospectively studied.

METHOD

A cohort of new onset PD patients from 1995 to 2002 was recruited from a regional hospital based movement disorder clinic. Subjects were classified into postural instability gait disorder (PIGD), tremor predominant type or mixed subtypes at presentation. All were evaluated yearly for development of sensory complaints, first significant fall, hallucinations, dementia, postural hypotension, speech disturbances, dysphagia and postural instability persisted during 'on' medication state (PIPon). Mortality and predictors of death were determined.

RESULTS

171 new onset PD patients were recruited. After a mean follow-up of 11.3±2.6 years, 50 (29%) patients died. The standardised mortality ratio was 1.1 (CI 0.8 to 1.5, p=0.34). 83 (49%) developed dementia, 81 (47%) had psychosis and 103 (60%) had sensory complaints. Postural hypotension was found in 58 (34%) patients, 108 (63%) had PIPon, 101 (59%) had falls, 102 (60%) had dysphagia, 148 (87%) had freezing of gait and 117 (68%) had speech disturbances. 46 (27%) were institutionalised whereas 54 (32%) lived independently. Dementia (HR 5.0, 95% CI 2.1 to 13.0), PIPon (HR 2.8, 95% CI 1.2 to 6.8), older onset (HR 1.05, 1 year increase in age, 95% CI 1.0 to 1.1) and PIGD type (HR 2.1, 95% CI 1.2 to 3.7) were independent predictors of death.

CONCLUSIONS

10 years into PD, a significant proportion of patients developed dopa resistant motor and non-motor features. Older onset, PIGD type, PIPon and dementia had a negative impact on survival. Standardised mortality ratio was 1.1.

TU-E-BRA-03: Real-Time Fiducial Detection and Prostate Movement Assessment with Cine MV Images in RapidArc Treatments

PURPOSE

To develop an algorithm for detection of metallic fiducial markers in cine MV images, and to assess the prostate movement during RapidArc treatment.

METHODS

A Varian TrueBeam linear accelerator (LINAC) was used to deliver RapidArc treatment for prostate patients. Cine images were acquired with the onboard electronic portal imaging device (EPID) using the MV therapeutic beam. Three metallic fiducial markers were implanted inside the prostate. To detect the fiducial position, we explicitly account for the possible marker blockage by MLC during beam modulation. If the marker is not blocked, we employ the planning coordinates of the marker centroids projected onto the cine MV images and perform template matching in the vicinity of its projection to localize the actual position of the marker. Displacements of the fiducial markers are assessed by comparing the actual and planned positions.

RESULTS

We analyzed ∼280 cine MV images acquired during a 55-sec RapidArc treatment for a prostate patient. The three markers were visible in about 46%, 52%, and 48% of the images, and at least one fiducial was visible during almost entire treatment (97% of the time). The marker detection algorithm agrees well with manual detection (< 0.2 mm). The mean displacement for each fiducial was 0.40 ± 0.42, 0.27 ± 0.29, and 0.46 ± 0.34 mm. The maximum displacement was 2.33, 1.75, and 2.23 mm.

CONCLUSIONS

An algorithm for automatic detection of fiducial markers in cine MV images has been developed. The prostate movement during a RapidArc treatment has been analyzed for a patient with implanted markers. Accurate target positioning is achieved at all times during treatment. In light of the random nature of intrafraction prostate motion, this work represents an important step toward real-time image-guided prostate radiation therapy.