A Queueing-Theoretic Foundation of Available Bandwidth Estimation: Single-Hop Analysis

Most existing available-bandwidth measurement techniques are justified using a constant-rate fluid cross-traffic model. To achieve a better understanding of the performance of current bandwidth measurement techniques in general traffic conditions, this paper presents a queueing-theoretic foundation of single-hop packet-train bandwidth estimation under bursty arrivals of discrete cross-traffic packets. We analyze the statistical mean of the packet-train output dispersion and its mathematical relationship to the input dispersion, which we call the probing-response curve. This analysis allows us to prove that the single-hop response curve in bursty cross-traffic deviates from that obtained under fluid cross traffic of the same average intensity and to demonstrate that this may lead to significant measurement bias in certain estimation techniques based on fluid models. We conclude the paper by showing, both analytically and experimentally, that the response-curve deviation vanishes as the packet-train length or probing packet size increases, where the vanishing rate is decided by the burstiness of cross-traffic.     

Time-utility function-driven switched Ethernet: packet scheduling algorithm, implementation, and feasibility analysis

We present a MAC-layer, soft real-time packet scheduling algorithm called UPA. UPA considers a message model where message packets have end-to-end timeliness requirements that are specified using Jensen's time-utility functions (TUFs). The algorithm seeks to maximize system-wide, aggregate packet utility. Since this scheduling problem is NP-hard, UPA heuristically computes schedules with a quadratic worst-case cost, faster than the previously best CMA algorithm. Our simulation studies show that UPA performs the same as or significantly better than CMA for a broad set of TUFs. Furthermore, we implement UPA and prototype a TUF-driven switched Ethernet system. The performance measurements of UPA from the implementation reveal its strong effectiveness. Finally, we derive timeliness feasibility conditions of TUF-driven switched Ethernet systems that use the UPA algorithm.     

Diagnosis of Prostate Cancer and Prostatitis Using near Infra-Red Fluorescent AgInSe/ZnS Quantum Dots

The link between the microbiome and cancer has led researchers to search for a potential probe for intracellular targeting of bacteria and cancer. Herein, we developed near infrared-emitting ternary AgInSe/ZnS quantum dots (QDs) for dual bacterial and cancer imaging. Briefly, water-soluble AgInSe/ZnS QDs were synthesized in a commercial kitchen pressure cooker. The as-synthesized QDs exhibited a spherical shape with a particle diameter of 4.5 ± 0.5 nm, and they were brightly fluorescent with a photoluminescence maximum at 705 nm. The QDs showed low toxicity against mouse mammary carcinoma (FM3A-Luc), mouse colon carcinoma (C26), malignant fibrous histiocytoma-like (KM-Luc/GFP) and prostate cancer cells, a greater number of accumulations in Staphylococcus aureus, and good cellular uptake in prostate cancer cells. This work is an excellent step towards using ternary QDs for diagnostic and guided therapy for prostate cancer.     

New Red- and Green-Emitting Phosphors, AYP2O7.5:RE3+ (A=Ca and Sr; RE=Eu and Tb) under Near-UV Irradiation

New red- and green-emitting phosphors, AY_{1− x} P₂O_7.5: x RE³⁺ (A=Ca and Sr; x =0.01, 0.03, 0.05, 0.10; RE=Eu and Tb) were synthesized by the conventional ceramic route and their photoluminescence properties under near-ultraviolet (UV) irradiation were investigated. It was found that CaYP₂O_7.5: Eu³⁺ phosphor emits strong red light when excited by a radiation of 394-nm wavelength and SrYP₂O_7.5:Eu³⁺ gives intense orange light when excited by a radiation of 396-nm wavelength. Strong green emission for AY_{1− x} P₂O_7.5:Tb³⁺ is also observed under near-UV irradiation (378 nm). When compared with emission intensity from a standard YPO₄:0.05Tb³⁺, the emission from SrYP₂O_7.5:0.05Tb³⁺ showed greater intensity values under the same excitation wavelength (378 nm). X-ray powder diffraction analysis showed that AYP₂O_7.5 has xenotime-type structure.     

Investigations on the Guanidination of Lysine in Proteins

The present study was conducted to compare the efficacy of five different reaction conditions on the guanidination of lysine in casein and to establish optimum lysine: O -methylisourea (OMIU) for maximum guanidination of lysine in casein and soya bean meal. The results indicate that the presence of glycine–NaOH buffer is not required for guanidination of proteins at pH 10·5. A OMIU concentration of 0·4 M was found to be as effective as 0·6 M for guanidination. Both OMIU–hydrogen sulphate and free OMIU were equally effective reagents in terms of conversion of lysine to homoarginine. The use of OMIU–hydrogen sulphate for guanidination and the use of ethanol to recover guanidinated protein, however, resulted in the formation of crystalline sodium sulphate, a known purgative agent, in the guanidinated material, and therefore are not recommended if the guanidinated protein is to be used in animal trials. The molar ratio of lysine: OMIU required for efficient lysine conversion to homoarginine varied for different protein sources. Ratios required for maximum conversion for casein and soya bean meal were determined to be 1:10 and 1:16, respectively. A simple procedure developed for the large-scale guanidination (5–10 kg batches) of proteins is also described. The results showed that guanidination of proteins can be easily scaled up from 20 g to 5–10 kg and that large-scale guanidination is feasible and efficient.     

Long time behaviour of the solution of a system of equations from new theory of shock dynamics

The new theory of shock dynamics gives a system of n + 2 equations, the solution of which determines the propagation of a discontinuity in the initial condition. For the model equation u_t + u u_x = 0, the long time behaviour of the solution is investigated for various confined initial data. The suitability of using Padé approximants for the solution is examined. Special exact solutions are obtained.     

Skeletal muscle fatigue and physical endurance of young and old mice

In order to evaluate the role played by muscular and extramuscular factors in the development of fatigue in old age, the time course of fatigue in isolated skeletal muscles and spontaneous motor activity and endurance of whole animals were monitored using young (3-6 months) and old (34-36 months) CF57BL/6J mice. The isolated extensor digitorum longus (EDL) and soleus muscles from old mice had smaller (P < 0.05) mass and developed lower (P < 0.02) maximal tetanic tension at 100-Hz stimulation than the muscles of young mice. During stimulation at 30 Hz every 2.5 s, a 50% decline in original tetanic tension occurred by 109 s in young EDL and 129 s in old EDL, but by 482 s in young soleus and 1134 s (projected) in old soleus, indicating more (P < 0.05) resistance to fatigue in old than young soleus. However, the old mice showed significantly fewer (P < 0.002) spontaneous ambulatory movements than the young mice. On a treadmill with a belt speed of 10 m/min at an inclination of 0 degrees, the old mice could only run for 22 min compared to 39 min ran by young mice (P < 0.02). They took more rest periods (P< 0.02) than the young mice. In a quantitative swimming monitor, the old mice swam for a shorter (P < 0.05) time than young mice (20.4 min compared to 28.6 min). Integrated swimming activity at 20 min was smaller (P < 0.05) in old mice than in young mice (413 g/s compared to 628 g/s). Hence increased fatigue in old age is not caused by impairment of processes within the muscles, but by impairment of central or extramuscular processes.     

Cost-sensitive partitioning in an architecture synthesis system for multicluster processors

Application-specific instruction processors (ASIPs) have great potential to meet the challenging demands of pervasive systems. This hierarchical system automatically designs highly customized multicluster processors. In the first of two tightly coupled components, design space exploration heuristically searches the basic capabilities that define the processor's overall parallelism. In the second, a hardware compiler determines the detailed architecture configuration that realizes the parallelism.     

Multi-media instructional approach to teaching linear programming

This paper describes different strategies employed in converting a lecture-oriented mathematical programming course to a Personalized Self-Paced Instructional (PSI) format. This is an elective course for students in science, engineering and management. A multi media instructional approach is used in the PSI system which combines traditional lectures, self-paced and individualized learning assisted by interactive computer programs and video taped instructional materials. This unique PSI system for mathematical programming provides maximum learning opportunity and flexibility to students. The author's experiences with the PSI system and the students' evaluation of the self-paced system are also discussed.     

Preparation of new niobates with the rutile structure

CrVNbO₆, FeVNbO₆ and NiV₂Nb₂O₁₀ have been prepared. The compounds are isostructural with the rutile phase of FeNbO₄, are nonstoichiometric with respect to all three constituent metal atoms, and show appreciable electrical conductivity.