Performance Comparison Between Different Tunneling Techniques Using Different Routing Protocols

Wireless Personal Communications - Migration to IPv6 becomes a priority with the draining of IPv4 addresses. But both IPv4 and IPv6 have different structures, and directly bringing IPv6 into the...     

Unequal Clustering Protocols for Wireless Sensor Networks—Taxonomy,Comparison and Simulation

Wireless Sensor Network (WSN) consists of randomly distributed sensor nodes which can collect, process, route and transmit data from their respective environment. Most of the research on WSN is oriented towards optimizing utilization of finite resources of Sensor Nodes to increase the overall network operative time. Recent literature on WSNs reveals that hierarchical routing unequal clustering methodologies are gaining popularity due to energy efficiency, load balancing and scalability. In literature, numerous surveys on clustering methodologies are available which address different equal clustering methods. The unequal clustering protocols, which have their own attributes viz. balance load distribution, hot spot mitigation and energy efficiency, are comparatively less explored. This motivated us to undertake the present study on the taxonomy, comparison and simulation analysis of different methodologies pertaining to less explored unequal clustering protocols. Our base metrics for comparison of different unequal clustering protocols are scalability, energy efficiency & load balancing capability of the resulting network. A comprehensive discussion has also been presented to highlight the various advantages and disadvantages of different unequal clustering protocols. Further, we have summarized the study of unequal clustering protocols in the tabular form.

     

Comorbid anxiety disorders in late-life depression

We examined the prevalence and correlates of comorbid anxiety disorders in two groups of older depressed patients assessed at the University of Pittsburgh. A total of 336 older outpatients and inpatients with major depression were comprehensively evaluated with several instruments including the Hamilton Depression Rating Scale, and either the SADS-L or the SCID for DSM-III-R. These patients presented with major depression, associated with a wide range of functional, cognitive, and medical impairment. One-third to one-half of them also presented with severe symptomatic anxiety. However, only a small proportion (less than 5%) met diagnostic criteria for lifetime or current panic, obsessive-compulsive, or phobic disorders. At baseline, lifetime comorbid anxiety disorders were associated with a higher rate of alcoholism and higher symptomatic anxiety. Lifetime comorbid anxiety disorders did not affect the rate of response of depression, but they were associated with a higher use of benzodiazepines and a 50% increase in the time outpatients needed to respond. These findings suggest that, even in psychiatric patients with major depression, the lifetime prevalence of anxiety disorders is lower in late life, but that it has important clinical and therapeutic implications.     

Reliability and validity of the 12-minute distance walk in patients with chronic obstructive pulmonary disease

Validity and test-retest liability of the 12-minute distance (12MD) walk, a measure of functional status, were examined in patients with chronic obstructive pulmonary disease. Four tests were administered at weekly intervals. Performance increased (p < .01) over the first three tests. Test-retest reliability was r34 = .98 (df = 46) for tests 3 and 4. The 12MD walk correlated with the Sickness Impact Profile, Physical Dimension (r = -.45); forced expiratory volume in 1 second % predicted ( r = .40); maximal inspiratory pressure (PImax) (r = .52); and exercise-related breathlessness (r = -.49). Exercise-related breathlessness and PImax accounted for 42% of the variance. The validity and reliability of the 12MD walk were supported.     

Segmentation of document images

Several methods for segmentation of document images (maps, drawings, etc.) are explored. The segmentation operation is posed as a statistical classification task with two pattern classes: print and background. A number of classification strategies are available. All require some prior information about the distribution of gray levels for the two classes. Training (either supervised or unsupervised) is employed to form these initial density estimates. Automatic updating of the class-conditional densities is performed within subregions in the image to adapt these global density estimates to the local image area. After local class-conditional densities have been obtained, each pixel is classified within the window using several techniques: a noncontextual Bayes classifier, Besag's classifier, relaxation, Owen and Switzer's classifier, and Haslett's classifier. Four test images were processed. In two of these, the relaxation method performed best, and in the other two, the noncontextual method performed best. Automatic updating improved the results for both classifiers     

Metastatic carcinoma to the mandible. Report of two cases

Two cases of rare metastases from malignant neoplasms to the posterior mandible in young adults are reported. Multiple imaging modalities were necessary to identify the many metastases and, in one case, the suspected primary site. Many of the radiographic images are presented for that case.     

A common pathway mediates retinoic acid and PMA-dependent programmed cell death (apoptosis) of neuronal cells

To assess the maternal and neonatal risk associated with high-order cesarean sections, a case-control study was carried out in two university affiliated maternity wards. The outcome of 154 pregnancies of women undergoing cesarean section for the 4th time or more was compared with 148 women sectioned for the 2nd or 3rd time and 132 women of similar age and parity after spontaneous birth. The main outcome measures were maternal operative and postoperative morbidity and neonatal prematurity and its complications, Apgar scores, and the need for intensive care. Women undergoing multiple (> or = 4) cesarean sections had significantly more intra-abdominal adhesions (P < 0.0001) than women sectioned for the 2nd or 3rd time. However, the time interval from incision to delivery and the total duration of operation were similar. The postoperative course was not adversely affected by multiple cesarean sections. A high incidence (16.2%) of preterm cesarean deliveries was noted in the study group. This was due to non-elective repeat cesarean delivery rather than to poor timing of scheduled cesarean sections. The significantly increased (P < 0.05) need for neonatal intensive care was explained by the higher occurrence of prematurity. Low Apgar scores (< or = 7) at 1 and 5 min were significantly (P < 0.01) related to multiple cesarean sections, even after controlling for the effect of gestational age. We conclude that multiple cesarean sections pose little risk for the mother, but may be associated with increased neonatal risk, attributed mainly to preterm non-elective cesarean sections.     

Shear Localization and Damage in AA5754 Aluminum Alloy Sheets

In this article, we study the Portevin-Le Chatelier (PLC) bands and their influences on strain localization and fracture in continuous cast (CC) AA5754 aluminum sheets. Three types of tensile tests are conducted: (1) tensile samples are pulled directly to fracture at 223 K, (2) tensile samples are pulled at 223 K to initiate diffuse necking followed by unloading and reloading to fracture at room temperature, and (3) tensile samples are pulled at 223 K to localized necking and unloaded followed by reloading to fracture at room temperature. Furthermore, in situ V-bending test coupled with deformation mapping using digital image correlation is used to study damage at large strains. The results show that PLC bands detect favorable geometrical sites for shear band initiation. The formation of shear bands precedes damage and damage is a consequence of shear band formation. This article was presented at Materials Science & Technology 2007, Automotive and Ground Vehicles symposium held September 16-20, 2007, in Detroit, MI.