Storage and synchronization for distributed continuous media

Advances in local area ATM networking make it possible to integrate digital audio and video, or continuous media (CM), into distributed computing environments. The temporal nature of CM introduces new requirements for acceptable end-to-end delay and jitter. This and an increased demand for bandwidth affect the design of modern, general purpose, operating systems. This paper addresses distributed system support for CM applications, focusing on the design and implementation of facilities for secondary storage and synchronization. We describe the relevant issues, along with details of our research project and its relationship to existing work. We emphasize experimentation and present results obtained with a prototype in an ATM testbed. These provide fresh insights into the role of operating system support for multimedia.     

Analysis of smartphone user mobility traces for opportunistic data collection in wireless sensor networks

The increasing ubiquity of smartphones coupled with the mobility of their users will allow the use of smartphones to enhance the operation of wireless sensor networks. In addition to accessing data from a wireless sensor network for personal use, and the generation of data through participatory sensing, we propose the use of smartphones to collect data from sensor nodes opportunistically. For this to be feasible, the mobility patterns of smartphone users must support opportunistic use. We analyze the dataset from the Mobile Data Challenge by Nokia, and we identify the significant patterns, including strong spatial and temporal localities. These patterns should be exploited when designing protocols and algorithms, and their existence supports the proposal for opportunistic data collection through smartphones.     

Enhanced streaming services in a content distribution network

Prism's content naming, management, discovery, and redirection mechanisms support: high-quality streaming media services in an IP-based content distribution network. IP content distribution networks (CDNs) are special-purpose networks that provide scalability by distributing many servers across the Internet “close” to consumers. Prism (Portal infrastructure for Streaming Media) is a CDN architecture for: distributing, storing, and delivering high quality streaming media over IP networks. The Prism-based stored-TV (STV) service allows users to select content based on the program's name as well as the time it was aired. Content stored inside the network is accessible throughout the whole Prism infrastructure. For example, a user in the US can access European TV content both live and on-demand. Prism also allows users to specify content to be stored in a “network-VCR” type service. The authors introduce the components of the Prism architecture     

Worst-Case Delay Control in Multigroup Overlay Networks

This paper proposes a novel and simple adaptive control algorithm for the effective delay control and resource utilization of end host multicast (EMcast) when the traffic load becomes heavy in a multigroup network with real-time flows constrained by (sigma, rho) regulators. The control algorithm is implemented at the overlay networks and provides more regulations through a novel (sigma, rho, lambda) regulator at each group end host who suffers from heavy input traffic. To our knowledge, it is the first work to incorporate traffic regulators into the end host multicast to control heavy traffic output. Our further contributions include a theoretical analysis and a set of results. We prove the existence and calculate the value of the rate threshold rho* such that for a given set of K groups, when the average rate of traffic entering the group end hosts rho macr > rho*, the ratio of the worst-case multicast delay bound of the proposed (sigma, rho, lambda) regulator over the traditional (sigma, rho) regulator is O(1/Kⁿ) for any integer n. We also prove the efficiency of the novel algorithm and regulator in decreasing worst-case delays by conducting computer simulations.     

Thyroid dysfunction is not associated with alterations in serum leptin levels

To determine if serum leptin levels are affected by thyroid dysfunction, we measured its concentration in serum samples from 25 euthyroid controls and 25 subjects each with hypothyroidism and thyrotoxicosis collected over a 3-month period. Mean leptin levels in the euthyroid (24.1 +/- 8.3 microg/L), hypothyroid (22.7 +/- 7.0 microg/L) and thyrotoxic (23.3 +/- 4.3 microg/L) groups were not significantly different. Data were available to express leptin in terms of body mass index (BMI) in 11 euthyroid, and 6 untreated hypothyroid and thyrotoxic individuals. There was a significant positive correlation between BMI and leptin level (r = 0.60, p = .0002) for this subgroup, irrespective of their thyroid status. These data suggest that leptin levels are not affected by thyroid dysfunction.     

Get wireless: a mobile technology spectrum

Mobile computing applications allow anytime, anywhere access to the Internet and corporate intranets. For several reasons, the market for wireless data services has grown at a much slower rate than wireless voice. Until recently, portable data devices were bulky, required heavy batteries, and didn't have integrated networking. Wireless services have also had to contend with narrow bandwidths, high access latency, and frequent disconnection. Added to this were inadequate coverage, expensive services, and perceived security problems. Finally, few applications were specifically designed with mobility in mind. New mobile technologies address these problems, making wireless data transmission an attractive alternative for individuals and enterprises. The next few years will see wireless data networks come into their own. Next year (year 2000), the market for wireless data networks is predicted to grow to six to eight million users with seven percent of the total wireless revenues. In fact, wireless data service is projected to be a multibillion-dollar market within five years. The combination of portable gadgets and wireless data services provides exciting opportunities for mobile computing applications     

Carcinosarcomas of the female genital tract. A pathologic study of 29 metastatic tumors: further evidence for the dominant role of the epithelial component and the conversion theory of histogenesis

Carcinosarcomas of the female genital tract have generally been regarded as a type of sarcoma. Recent evidence suggests, however, that they may be more closely related to carcinoma. The histologic features of 29 carcinosarcomas with documented metastases were analyzed to study the relative importance of the carcinomatous and sarcomatous components and attempt to provide further evidence on the histogenesis of these neoplasms. Patients' ages ranged from 33 to 81 years (mean, 68). The primary tumor originated in the uterus in 17 cases, the ovary in 11, and the fallopian tube in one. Heterologous sarcoma was present in 21 of the primary tumors (72%). Myometrial invasion was present in all 15 of the uterine tumors treated with hysterectomy and consisted only of the carcinomatous component in 12 cases (80%). In two cases, which possibly developed as "collision"-type carcinosarcomas, the myometrium was separately invaded by carcinoma and sarcoma. Myoinvasive tumor consisted solely of sarcoma in one case. Lymphatic-vascular invasion was found in 10 of the primary tumors (eight uterine, two extrauterine) and consisted of pure carcinoma in all instances. The cellular composition of 62 metastases was evaluated. Of these, 51 metastases were diagnosed concurrently with the primary tumor in 21 patients (73%). Eleven metastases were diagnosed from 2 to 26 months after initial treatment. Carcinoma only was found in 43 metastases (70%), both carcinoma and sarcoma in 15 (24%), and sarcoma alone in four (6%). A total of 35 lymph node metastases occurred in 10 cases, consisting of carcinoma alone at 34 sites. The sole example of a purely sarcomatous lymph node metastasis occurred in one of the possible uterine "collision"-type tumors. Intraperitoneal metastases to serosal surfaces or the omentum occurred in 19 cases and consisted of both carcinoma and sarcoma in 14 and carcinoma only in five. Vaginal metastases occurred in four cases and consisted of only carcinoma in two, carcinoma and sarcoma in one and only sarcoma in one. Four patients had distant organ metastases, including one each to the liver (carcinoma only), breast (carcinoma only), bone marrow (sarcoma only), and brain (sarcoma only). Of the 51 concurrent metastases, only carcinoma was present in 37 (73%), both carcinoma and sarcoma in 13 (26%), and sarcoma alone in one. Of the 11 subsequent metastases, carcinoma alone was found in six (55%), sarcoma alone in three (27%), and both carcinoma and sarcoma in two (18%).(ABSTRACT TRUNCATED AT 400 WORDS)     

Connectivity and coverage maintenance in wireless sensor networks

One of the main design challenges for wireless sensor networks (WSNs) is to obtain long system lifetime without sacrificing system original performance such as communication connectivity and sensing coverage. A large number of sensor nodes are deployed in redundant fashion in dense sensor networks, which lead to higher energy consumption. We propose a distributed framework for energy efficient connectivity and coverage maintenance in WSNs. In our framework, each sensor makes self-scheduling to separately control the states of RF and sensing unit based on dynamic coordinated reconstruction mechanism. A novel energy-balanced distributed connected dominating set algorithm is presented to make connectivity maintenance; and also a distributed node sensing scheduling is brought forward to maintain the network coverage according to the surveillance requirements. We implemented our framework by C++ programming, and the simulation results show that our framework outperforms several related work by considerably improving the energy performance of sensor networks to effectively extend network lifetime.     

Defective pancreatic beta-cell glycolytic signaling in hepatocyte nuclear factor-1alpha-deficient mice

Mutations in the hepatocyte nuclear factor-1alpha (HNF-1alpha) gene cause maturity onset diabetes of the young type 3, a form of type 2 diabetes mellitus. In mice lacking the HNF-1alpha gene, insulin secretion and intracellular calcium ([Ca2+]i) responses were impaired following stimulation with nutrient secretagogues such as glucose and glyceraldehyde but normal with non-nutrient stimuli such as potassium chloride. Patch clamp recordings revealed ATP-sensitive K+ currents (KATP) in beta-cells that were insensitive to suppression by glucose but normally sensitive to ATP. Exposure to mitochondrial substrates suppressed KATP, elevated [Ca2+]i, and corrected the insulin secretion defect. NAD(P)H responses to glucose were substantially reduced, and inhibitors of glycolytic NADH generation reproduced the mutant phenotype in normal islets. Flux of glucose through glycolysis in islets from mutant mice was reduced, as a result of which ATP generation in response to glucose was impaired. We conclude that hepatocyte nuclear factor-1alpha diabetes results from defective beta-cell glycolytic signaling, which is potentially correctable using substrates that bypass the defect.