A Nonline-of-Sight Error-Mitigation Method for TOA Measurements

In wireless location, nonline-of-sight (NLOS) errors are a major error source. To improve positional performance, these errors should be identified and mitigated before measurements are used in position computations. A novel NLOS mitigation algorithm is proposed in this paper. Employing system redundancy, the algorithm derives from the distribution function of hyperbolic intersections, which is an intermediate mobile location. Cost functions based on the intermediate position are then created for each time-of-arrival measurement. NLOS errors are detected and mitigated via hypothesis tests performed on the cost functions. Simulation tests are presented in this paper, and the results verify the effectiveness of this NLOS-error-mitigation method. This paper also demonstrates that algorithm performance depends closely on receiver noise. Reducing receiver noise or providing the intermediate mobile location via external aiding can improve performance     

Observations on the ultrastructural preservation of the nucleus in the myxomycete Physarum polycephalum as observed in resinless sections

The ultrastructural preservation of the nucleus in both myxamoebae and macroplasmodia of the slime mold Physarum polycephalum was investigated using specimens processed with diethylene glycol distearate or Plexiglass. Following specimen embedding in either of these media, the polymers were dissolved from the semithin sections, which were then dried by the critical point process. In these resinless preparations, nuclei appeared to be pervaded by a complex network of fibrils of various diameters among which granules of different sizes were scattered. At least five different types of fibrils were detected in plasmodial as well as in amoebal nuclei. Resinless preparations obtained from diethylene glycol distearate processed specimens showed a number of easily recognized artifacts, some of which were noticeably less conspicuous when samples were embedded in Plexiglass. In both cases, no indication was obtained that extensive extraction of material had occurred during resin removal by solvents. The various artifacts that were produced following processing with these two media thus seem to have mostly developed during infiltration and hardening, rather than during dissolution of the polymers or critical point drying of the sections.     

Intraocular gene transfer of ciliary neurotrophic factor prevents death and increases responsiveness of rod photoreceptors in the retinal degeneration slow mouse

Several mutations causing both photoreceptor degeneration and malfunction have been identified in humans and animals. Although intraocular injection of trophic factors has been shown to reduce photoreceptor death in a few conditions of rapid photoreceptor loss, it is unclear whether long-term beneficial changes in functional properties of affected photoreceptors can be obtained by treatment with these factors. The rds/rds mouse is a spontaneous mutant bearing a null mutation in the rds/peripherin gene, which is linked to many forms of dominant retinal degenerations in humans. Here, we report that intraocular adenovirus-mediated gene transfer of ciliary neurotrophic factor (CNTF) in this mutant reduces photoreceptor loss, causes a significant increase in the length of photoreceptor segments, and results in a redistribution and an increase in the retinal content of the photopigment rhodopsin. These effects are accompanied by a significant increase in the amplitude of the a- and b-waves of the scotopic electroretinogram. These results suggest that continuous administration of CNTF could potentially be useful for the treatment of some forms of retinal degeneration.     

Education in domestic violence

A baccalaureate-level, mandatory course on the social aspects of violence against women is being given as part of the curriculum at the Université du Québec à Rimouski. The course has been offered since 1990 and includes a complete array of teaching techniques such as lectures, simulations and role playing. Its aim is to impart knowledge, develop awareness, promote a change of attitudes and develop intervention abilities for nurses who may come in contact with domestic violence situations. Prior to implementation, an exploratory study was completed to determine student nurses' perceptions of domestic violence. Results indicate that, prior to taking the course, domestic violence was perceived as an individual problem. Respondents (26 female and 2 male) generally accepted society's prejudices of domestic violence as fact and ignored research results that pointed to the social realities. By the end of the course, the respondents' knowledge of the social aspects of domestic violence was better integrated. The authors conclude that specific training on domestic violence can modify false perceptions and help nurses develop the necessary competencies to deal with these situations.     

Effect of lysoplatelet-activating factor on human sperm fertilizing ability

OBJECTIVE: To evaluate the penetration rates in the hamster zona-free oocyte sperm penetration assay (SPA) after exposure of spermatozoa to lysoplatelet-activating factor (LPAF) and lysophosphatidyl choline (LPC). DESIGN: Washed human spermatozoa were exposed to 100 microM of LPAF or LPC, followed by the assessment of their fertilizing ability using the SPA. The percentage of penetration, the sperm binding in the SPA, the percentage of motile spermatozoa, and the acrosome reaction rates were quantified. SETTING: Private research and university laboratories. PATIENTS, PARTICIPANTS: Fresh and frozen semen samples from fertile donors with proven fertility were used as well as fresh semen from infertile patients attending a fertility clinic. All the infertile patients had abnormal semen analysis. INTERVENTIONS: Human spermatozoa were incubated for 90 minutes in the presence or absence of LPAF or LPC at 100 microM with 0.3% albumin in Ham's F-10 (GIBCO, Dorval, Quebec, Canada), and their fertilizing ability was evaluated using the SPA. The effect of these lysophospholipids on the percentage of acrosome reaction was evaluated with a fluorescent microscopy technique. RESULTS: The penetration rates of the SPA in male factor increased significantly from 3% +/- 6% with controls to 19% +/- 9% and 34% +/- 22% after incubation with LPC and LPAF, respectively. Sperm-oocyte binding was not significantly increased in this group. Sperm penetration assay penetration rates were also increased in fertile cryopreserved spermatozoa with LPC and LPAF. In this group, the acrosome reaction was significantly increased from 2% +/- 1% in controls to 10% +/- 6% and 8% +/- 3% after incubation with LPC and LPAF, respectively. CONCLUSION: Lysoplatelet-activating factor and LPC independently increased the penetration rate of spermatozoa and the percentage of acrosome reaction. Lysophosphatidylcholine and LPAF may be beneficial in the treatment of spermatozoa with male factor infertility and may increase fertilization rates in IVF.     

An empirical method of determining the less than two micrometre fraction on a Leeds-Northrup model 7991 microtrac laboratory particle size analyzer (1.9 to 176 μm)

While plotting log-log size distributions of very fine material determined by the Leeds-Northrup Model 7991 Mictrotrac Particle Size Analyzer, a ‘tailing off’ effect was observed. This ‘tailing off’ effect implied that the material contained little or no fines. It was decided that this bias was because some of the material was beyond the lower detection limit of this model. A very simple but accurate empirical method relating uncalibrated volume, dV, with an absolute weight is described to calculate the amount of this fine material, and as a result, correct the bias in the size distribution.This method has been employed on eight different materials with excellent reproducibility and an accuracy of ± 2% at a 99% confidence interval.     

Teaching children about bicycle safety: An evaluation of the New Jersey Bike School program

There are multiple health and environmental benefits associated with increasing bicycling among children. However, the use of bicycles is also associated with severe injuries and fatalities. In order to reduce bicycle crashes, a bicycling education program was implemented in selected New Jersey schools and summer camps as part of the New Jersey Safe Routes to School Program. Using a convenience sample of participants to the program, an opportunistic study was designed to evaluate the effectiveness of two bicycle education programs, the first a more-structured program delivered in a school setting, with no on-road component, and the other a less structured program delivered in a summer camp setting that included an on-road component. Tests administered before and after training were designed to assess knowledge acquired during the training. Questions assessed children's existing knowledge of helmet use and other equipment, bicycle safety, as well as their ability to discriminate hazards and understand rules of the road. Participating children (n = 699) also completed a travel survey that assessed their bicycling behavior and their perception of safety issues. Response to individual questions, overall pre- and post-training test scores, and changes in test scores were compared using comparison of proportion, t-tests, and ordinary least-squares (OLS) regression. Improvements between the pre-training and post-training test are apparent from the frequency distribution of test results and from t-tests. Both summer camps and school-based programs recorded similar improvements in test results. Children who bicycled with their parents scored higher on the pre-training test but did not improve as much on the post-training test. Without evaluating long-term changes in behavior, it is difficult to ascertain how successful the program is on eventual behavioral and safety outcomes.     

Embryonic resistance to tumour necrosis factor-alpha mediated cytotoxicity: novel mechanism underlying maternal immunological tolerance to the fetal allograft

The cytokine tumour necrosis factor-alpha (TNF alpha) has been postulated to play an essential role in the cytotoxic activity of cell-mediated immunity against allogenic or tumour cells invading the host. Several tumour cell lines, however, are resistant to TNF mediated cytotoxicity and respond paradoxically by cellular proliferation and by autocrine secretion of TNF alpha. In view of the metastatic character of the mammalian embryo, the aim of this study was to assess the potential of murine embryos to secrete TNF alpha in vitro, to express TNF receptors and to resist TNF alpha mediated cytotoxicity during their in-vitro development to the blastocyst stage. The potential of human embryos to secrete TNF alpha in vitro until the blastocyst stage was also investigated. From a total of 11 human embryos, which were allowed to proceed to blastocyst formation, seven secreted TNF alpha in the range of 2-117 pg/ml/24 h. A total of 123 C57BL/6J mouse embryos were studied of which 55% secreted TNF alpha in the range of 1.25-3.95 mg/ml/24 h. The presence of high levels of exogenous TNF alpha (10-300 IU) was not detrimental to the in-vitro development of murine embryos. Using immunohistochemical techniques, we were not able to detect the presence of type I or II TNF receptors on the surface of murine embryos. Our findings suggest that human and C57BL/6J murine embryos have the potential to secrete TNF alpha in vitro during the developmental stages leading to blastocyst formation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Perioperative mortality after pneumonectomy: analysis of risk factors and review of the literature

Small alpha-RNP of K-562 cells contain a small RNA as an RNA component, this RNA is homologous to Alu-repeating sequences of human DNA. When cells are exposed to dimethylsulfoxide, an agent inducing cell differentiation along the erythroid pathway, the content of both high-molecular-weight (heterogeneous nuclear and messenger) RNA enriched with Alu repeats and low-molecular-weight specific RNA, small Alu-homologous alpha-RNA undergoes a coordinated decrease. Using the technique of northern blot hybridization, we have demonstrated nonuniform distribution of Alu repeats both in the fraction of total low-molecular-weight RNA of the cytoplasm as well as in the fraction of messenger RNA. It is proposed that alpha-RNA (alpha-RNP) participates in the control of expression of non-linked Alu-containing genes.     

Recording the oscillatory potentials of the electroretinogram with the DTL electrode

Suprathreshold photopic oscillatory potentials recorded with a DTL electrode were compared to those obtained with a Lovac corneal electrode. The overall oscillatory potential response (sum of oscillatory potentials) recorded with the DTL electrode was half of that obtained with the Lovac electrode. However, there was no evidence of a selective attenuation (or amplification) of any given oscillatory potential with the DTL electrode. Similarly, the oscillatory potential relative amplitude ratios and the peak times of the oscillatory potentials were identical for both electrodes. Our findings clearly indicate that the DTL electrode is adequate to record the high-frequency oscillatory potentials. Given the low cost and ease of use, as well as the disposable nature of the DTL electrode, we believe that electroretinographic specialists should seriously consider a wider utilization.