Collision-Free and Low-Latency Scheduling Algorithm for Broadcast Operation in Wireless Ad Hoc Networks

It is desirable for broadcast operation in wireless ad hoc network to prevent collision and achieve low latency at the same time. In this letter, we propose a greedy broadcast scheduling algorithm based on the graph theory of Maximum Weight Independent Set (MWIS) problem. During each broadcast wave cycle, MWIS is able to find the optimal selection of forwarders so that maximum number of untouched nodes is covered without incurring collision. Numerical results show that this algorithm could produce better performance results than recent 2-step approach.     

QoS-Constrained information-theoretic sum capacity of reverse link CDMA. Systems

The information-theoretic sum capacity of reverse link CDMA systems with QoS constraints is investigated in this paper. Since the reverse link of CDMA systems are, for a given channel and noise conditions, interference-limited, the sum capacity can be achieved by optimally allocating the transmit powers of the mobile stations with the optimal (Shannon) coding. Unfortunately, the sum capacity is usually achieved via unfair resource allocation. This can be avoided by imposing QoS constraints on the system. The results here show that for a single cell system, the sum capacity can be achieved while meeting the QoS constraints with a semi-bang-bang power allocation strategy. Numerical results are then presented to show the multi-user diversity gain and the impact of QoS constraints. The implication of TDM operation in a practical reverse link CDMA system is also discussed.     

Therapeutic Ultrasound Halts Progression of Chronic Kidney Disease In Vivo via the Regulation of Markers Associated with Renal Epithelial–Mesenchymal Transition and Senescence

Low-intensity pulsed ultrasound (LIPUS), a therapeutic type of ultrasound, is known to enhance bone fracture repair processes and help some tissues to heal. Here, we investigated the therapeutic potential of LIPUS for the treatment of chronic kidney disease (CKD) in two CKD mouse models. CKD mice were induced using both unilateral renal ischemia/reperfusion injury (IRI) with nephrectomy and adenine administration. The left kidneys of the CKD mice were treated using LIPUS with the parameters of 3 MHz, 100 mW/cm², and 20 min/day, based on the preliminary experiments. The mice were euthanized 14 days after IRI or 28 days after the end of adenine administration. LIPUS treatment effectively alleviated the decreases in the body weight and albumin/globulin ratio and the increases in the serum renal functional markers, fibroblast growth factor-23, renal pathological changes, and renal fibrosis in the CKD mice. The parameters for epithelial–mesenchymal transition (EMT), senescence-related signal induction, and the inhibition of α-Klotho and endogenous antioxidant enzyme protein expression in the kidneys of the CKD mice were also significantly alleviated by LIPUS. These results suggest that LIPUS treatment reduces CKD progression through the inhibition of EMT and senescence-related signals. The application of LIPUS may be an alternative non-invasive therapeutic intervention for CKD therapy.     

Amniotic fluid alpha-fetoprotein levels during midtrimester of trisomy pregnancies

To investigate the association between low amniotic fluid alpha-fetoprotein (AFP) and trisomy pregnancies, we retrospectively reviewed 26 trisomy pregnancies including 18 fetuses with Down's syndrome and eight with trisomy 18. The amniotic fluid AFP median values of Down's syndrome, trisomy 18, and the study groups were 0.73 MoM, 1.15 MoM, and 0.85 MoM, respectively. There was a significant difference between the mean values of the Down's syndrome-affected fetuses (0.78 +/- 0.29 MoM) and that of the control group (p < 0.001), whereas no such difference was found for that of trisomy 18-affected fetuses (1.16 +/- 0.38 MoM). Only three patients in the study group (3/26, 11.5%) had an amniotic fluid AFP value below 0.5 MoM, including the two cases of Down's syndrome (2/18, 11.1%) and one case of trisomy 18 (1/8, 12.5%). Most of the values for the trisomy pregnancies were within the normal range, thereby precluding the possibility of using this measurement as an alternative to fetal karyotyping as a screening test for Down's syndrome or other trisomy pregnancies.     

ULTRASONIC CHARACTERIZATION OF THREE-PHASE SLURRIES

An ultrasonic technique is under development for measuring solids concentration in a three-phase slurry reactor. Preliminary measurements have been made on slurries consisting of water, glass beads, and air bubbles. The data show that both the sound speed and attenuation are well-defined functions of both the solid and gas concentrations in the slurries. A simple model is proposed to correlate the solids concentration with the measured ultrasonic signals.     

A novel CDMA multiuser interference cancellation receiver withreference symbol aided estimation of channel parameters

A novel multistage successive interference cancellation scheme is proposed which operates on the reverse code-division multiple-access (CDMA) link using binary phase shift keying (BPSK) modulation, coherent detection and reference symbols to obtain channel estimates. The results of a single cell multiuser investigation demonstrate increased traffic capacity. However, this increase is initially very moderate due to corruption of the channel estimates by interference from symbols not yet demodulated and cancelled. A modification in the transmitted signal structure addressing this problem is proposed. The results of a single cell analysis of the modified cancellation scheme demonstrate that the system's traffic capacity reaches approximately 80% of that of a multistage successive interference cancelling receiver operating with the perfect knowledge of channel parameters. A subsequent multicell investigation shows that for a hexagonal cell geometry with a path loss exponent of four and without any forward error correction (FEC) coding or cell sectorization, the system capacity compares very favorably with that of the IS-95 system, which employs powerful error control coding. Capacities with other path loss exponents and cell geometries are also investigated. The results show a substantial traffic capacity increase over that of a comparable receiver without interference cancellation     

Postpartum hemorrhage of the uterine artery rupture

Fatty masses, especially solid lipomas, in the paediatric abdomen are very rare. We present such a case, that of an 11-year-old boy who was admitted with abdominal pain and distension. The pre-operative diagnosis of lipoma was suggested by US and CT. The diagnosis of simple lipoma arising in the leaves of the small bowel mesentery, without immature cells, was verified microscopically after the operation. The tumour was enucleated from the mesenterium leaving the intestine intact. We underline the importance of US and CT as pre-operative diagnostic tools.     

Time-dependent rheological properties and transient structural states of entangled polymeric liquids—A kinetic network model

A kinetic network model has been developed to describe the nonlinear rheological behavior of entangled polymer solutions and melts in either steady-state or transient flows. This model is based on the concept of flow-induced structure variation, controlled by the simultaneous existence of entanglement loss and regeneration. When steady-state is attained, both processes occur at the same rate and the structural state (entanglement density) of the fluid remains constant with time. Under transient flow conditions, the fluid structure becomes time-dependent as a result of unequal rates of the two competing processes affecting entanglement density. The viscoelastic response of the fluid is, in turn, influenced by the varying structural state. This is incorporated into the model through the use of structure-dependent coefficients in the contravariant Maxwell constitutive equation for entanglement stress. Model predictions are generated for a number of transient flow programs, including the stress growth and relaxation, interrupted flow, sudden change in shear rate, and nonlinear creep experiments. Comparison with literature data supports not only the qualitative success but also the quantitative ability of this model.