Paraintestinal mesenteric abscess and chronic peritonitis in a bull

A 2-year-old bull was examined because of intermittent anorexia, signs of mild colic, and weight loss of 3 weeks' duration. A tympanitic resonance (ping) could be heard during simultaneous auscultation and percussion of the right paralumbar fossa, and a mass could be felt in the right dorsal quadrant of the abdominal cavity during palpation per rectum. Right flank laparotomy was performed, and intraoperative ultrasonography and ultrasound-guided fine-needle aspiration were used to determine that the mass was an abscess. However, the abscess could not be removed or drained into the colon because of extensive adhesions to other organs. Because the owner refused to pursue continued medical treatment, the bull was euthanatized. At necropsy, the abscess was found to be connected to a caudal mesenteric lymph node through a fistula. Histologic evaluation of the lymph node revealed hyperplastic lymphadenitis, and an alpha-hemolytic streptococcus was recovered from the abscess fluid. The most likely possibility for the findings in this bull were that the lymphadenitis was of hematogenous origin and that the abscess developed as a direct extension of the infectious process, similar to development of mesenteric abscesses in horses with chronic streptococcal infection (i.e., strangles).     

Steady-State Pharmacokinetics of a Multiparticulate Matrix Sustained-Release Theophylline Preparation

A novel multiparticulate matrix sustained-release theophylline preparation was evaluated in comparison with a reference product, Neulin-SR®, in a multiple-dose administration study, conducted according to a randomized, two-way crossover design involving 12 healthy volunteers. Comparison was made using the parameters, area under the serum concentration-time curve from time 0 to 12 hr (AUC_0-12), time to reach peak serum concentration (T_max), peak serum concentration (C_max), trough serum concentration (C_min), average drug concentration (C_av), degree of fluctuation (DF), percentage of time serum drug concentrations lie within the therapeutic range (occupancy time) and time for 50% of dose absorbed (T_50%). The parameters, C_max, C_min, AUC_0-12 C_av, and DF were logarithmic transformed prior to statistical analysis. A statistically significant difference was obtained between the values of the two preparations in the T_max, C_min, DF, and T_50%; but not in the C_max, AUC_0-12, C_av, and occupancy time. These findings suggest that the novel preparation has a more sustained rate but equivalent extent of absorption compared to Neulin-SR, leading to a more uniform steady-state serum profile.     

Cell density-sensing in Dictyostelium by means of the accumulation rate, diffusion coefficient and activity threshold of a protein secreted by starved cells

The simple eukaryote Dictyostelium discoideum grows as an amoeba on leaf and soil surfaces. When starved, the amoebae aggregate and differentiate. The amoebae can also be induced to differentiate as isolated cells submerged in buffer, if the buffer contains a sufficiently high concentration of a protein (CMF) secreted by starved cells. CMF is also necessary for aggregation and differentiation on surfaces. This indicated that CMF has either an autocrine function or is part of a density-sensing system. To distinguish between these two possible functions, we first examined the rate at which CMF is accumulated and the activity threshold of cells for CMF, since both parameters will affect whether a cell can provide enough CMF to self-stimulate. We find that CMF potentiates its own accumulation, and that otherwise the accumulation rate and activity threshold are affected very little by a variety of physiological conditions. We then use diffusion calculations to show that even after many hours of continuous secretion, the CMF concentration adjacent to an isolated starved cell on a leaf or soil surface will be too low to allow differentiation, whereas an extracellular concentration of CMF sufficiently high to allow differentiation will occur when starved cells are at high densities. We find a close match between the predicted and experimentally observed density necessary for differentiation. The theoretical and observed behavior of cells at different cell densities suggests that due to its accumulation rate, diffusion coefficient, and activation threshold, CMF can function as part of a cell density-sensing system which allows Dictyostelium cells in the wild to co-ordinate their development.     

Sequence estimation over the slow nonselective Rayleigh fadingchannel with diversity reception and its application to Viterbi decoding

The authors consider minimum error probability detection of a data sequence transmitted using linear-suppressed carrier modulations, specifically phase-shift keying (PSK), over the Gaussian channel with slow nonselective Rayleigh fading. Complete channel interleaving/deinterleaving and diversity reception are assumed. The problem is considered with application to Viterbi decoding in particular. It is first shown that the two presently available receivers, namely, the conventional maximum likelihood (ML) receiver and the simultaneous estimation receiver, do not perform adequately for this problem. A two-stage receiver is proposed in which the unknown channel fading gains are estimated in the first stage prior to data sequence estimation in the second stage. This receiver is shown to perform adequately, and leads to an efficient receiver/decoder for Viterbi decoding of convolutionally trellis-coded sequences. The issue of optimum estimation of channel fading gains is clarified. The bit error probability of the receiver/decoder is analyzed, and numerical performance results are presented     

Design of discrete-coefficient FIR filters on loosely connectedparallel machines

This paper presents a new branch-and-bound mixed-integer linear programming-based algorithm for designing discrete-coefficient finite-impulse response (FIR) filters using a cluster of workstations as the computation platform. The discrete coefficient space considered is the sum of signed power-of-two space, but the technique is also applicable to other discrete coefficient spaces. The key issue determining the success of the algorithm is the ability to partition the original problem into several independent parts that can be distributed to a cluster of machines for solution. The master-slave model is adopted for the control of the machines. Test run results showed that super linear speedup (i.e., the speedup factor is more than the number of machines running in parallel) may be achieved     

An examination of long-rod penetration in micro-scale using particles

The authors show how using particle simulations one can try to solve the problems out of reach of classical models based on the matter, momenta and energy flows continuity. Being aware about limitations of the method applied, the paper presents the perspectives of particle based simulations considering as an example the penetration mechanism investigation in micro-scale.     

Theory and experiment of a coaxial probe fed hemisphericaldielectric resonator antenna

A hemispherical dielectric resonator antenna fed by a coaxial probe is studied both theoretically and experimentally. The Green's function for the evaluation of the input impedance is derived rigorously and expressed in a form convenient for numerical computations. The method of moments is used to obtain the probe current from which the input impedance of the DR antenna is calculated. Both delta gap and magnetic frill source models are considered. Moreover, the results using a reduced kernel as well as the exact kernel are presented. Both entire basis (EB) and piecewise sinusoidal (PWS) expansion modes are used and the results are compared. The effects of the probe length, feed position, and dielectric constant on the input impedance are discussed. Finally, the theoretical radiation patterns for the first three resonant modes (TE₁₁₁, TM₁₀₁, and TE₂₂₁) of the DR antenna are presented