Trackability as a cue for potential obstacle identification and 3-D description

In many man-made environments, obstacles in the path of a mobile robot can be characterized asshallow, that is, they have relatively small extent in depth compared to the distance from the camera. We present a framework for segmenting shallow structures from their background over a sequence of images. Shallowness is first quantified asaffine describability. This is embedded in a tracking system within which hypothesized model structures undergo a cycle of prediction and model-matching. Structures emerge either as shallow or nonshallow based on theiraffine trackability. Two major contributions of this work are (i) aggregate object tracking based on 3-D motion and structure constraints in constrast with traditional primitive feature tracking based on image motion heuristics, and (ii) use of temporal behavior for object segmentation and 3-D reconstruction.     

Development of an exostosis following a free gingival graft: case report

A new, field-adapted, colorimetric method for detecting sulfonamide drugs in urine is described. The method uses the color reagent, p-dimethylaminocinnamaldehyde, and has a detection limit of about 1 microgram/ml. Analysis of 35 samples collected in the field, comparing results obtained with the colorimetric field test with those obtained using high-performance liquid chromatography, indicated a calculated sensitivity value of 94% and a specificity value of 94% for the test to detect the presence of sulfonamides. The field test can be modified to allow quantitation of sulfonamides in urine in field situations, using a hand-held, portable photometer for measuring the absorbance of test solutions. For this test, calculated coefficients of variation for day to day reproducibility were < or = 5% at sulfonamide concentrations > or = 3 micrograms/ml. This new test for detecting the presence of sulfonamides in urine is more sensitive and reliable than the presently used Bratton-Marshall test.     

Diterpenoids

Our aim was to review the results and to investigate the prognosis in a prospective study of aggressive surgical treatment in 186 patients (59% women, 41% men, age 18 to 65 years) treated during the past 9 1/2 years by conventional laying open of the fistula (n = 71), endorectal advancement flap repair (n = 89) and by fistulectomy without internal sphincterotomy (n = 37). 54 (29%) patients had intersphincteric, 57 (30.5%) transsphincteric, 10 (5.5%) suprasphincteric, 37 (20%) low rectovaginal and 28 (15%) had complex fistulas without internal opening. Four sphincter saving techniques were performed by the high and fistulas (n = 89) with primary occlusion of the intraanal ostium and endorectal mucosal flap (n = 29), endorectal advancement flap (n = 41), anodermal flap (n = 8) and transperineal repair with levator interposition (n = 11). Postoperatively 18 cases (20.2%) of suture leakage occurred, 27% in the mucosal flap group, 17.6% in the advancement flap group, 12.5% in the anodermal group, and 27% in the transperineal group. A complete primary healing of perianal wounds was noted in 73% of the patients within 6 months. The presence of rectal disease (n = 77) did not adversely influence the rate and duration of healing. Persistent or recurrent fistula occurs in 29 patients (15.6%), 22% in the sphincter saving group, 4% in the intersphincteric group and 32% in the complex type of fistulas. Disturbance of continence was observed in 9 patients (4.8%). Postoperatively, there was no significant change in resting anal pressure and maximum voluntary conctraction pressure in any fistula group (n = 104). CONCLUSION: The presented clinical and functional long term results of patients with Crohn's fistulas underline the importance of experience in the treatment of perianal fistula disease. A successful treatment depends primarily on an aggressive therapeutic strategy and the appropriate method of operation.     

Nature of methamphetamine-induced rapid and reversible changes in dopamine transporters

The nature of methamphetamine-induced rapid and transient decreases in dopamine transporter activity was investigated. Regional specificity was demonstrated, since [3H]dopamine uptake was decreased in synaptosomes prepared from the striatum, but not nucleus accumbens, of methamphetamine-treated rats. Differences among effects on dopamine transporter activity and ligand binding were also observed, since a single methamphetamine administration decreased [3H]dopamine uptake without altering [3H]WIN35428 ([3H](-)-2-beta-carbomethoxy-3-beta-(4-fluorophenyl)tropane 1,5-naphthalenedisulfonate) binding in synaptosomes prepared 1 h after injection. Moreover, multiple methamphetamine injections caused a greater decrease in [3H]dopamine uptake than [3H]WIN35428 binding in synaptosomes prepared I h after dosing. Finally, decreases in [3H]dopamine uptake, but not [3H]WIN35428 binding, were partially reversed 24 h after multiple methamphetamine injections. Western blotting indicated that saline- and methamphetamine-affected dopamine transporters co-migrated on sodium dodecyl sulfate (SDS) gels at approximately 80 kDa, and that acute, methamphetamine-induced decreases in [3H]dopamine uptake were not due to loss of dopamine transporter protein. These findings demonstrate heretofore-uncharacterized features of the acute effect of methamphetamine on dopamine transporters.     

Skin care strategies in a skilled nursing home

1. Pressure ulcers continue to be a serious problem in nursing home settings. They are significant as a source of discomfort and disability among nursing home residents, as well as a source of financial concern for the institutional agencies responsible for resident care. 2. Prevention and intervention at the earliest stages of pressure ulcer development offer the most effective approaches to mediating the human and economic costs imposed by pressure ulcers. 3. Strategies that are effective in reducing both the development and severity of pressure ulcers can be successfully implemented in long-term care settings. Further studies are needed that will provide additional support for the strategies and protocols used in this study.     

Effects of hypoxia on urinary organic acid and hypoxanthine excretion in fetal sheep

Severe birth asphyxia leads to a transient organic aciduria and increased hypoxanthine excretion. To investigate its origin and timing, we analyzed urine from 12 late gestation fetal sheep in utero subjected to moderately severe isocapnic hypoxia for 1 h. In six fetuses the carotid sinus nerves were cut to determine whether reflex peripheral vasoconstriction contributed to the changes in excretion. After a control period of 1 h, maternal inspired oxygen was reduced for 1 h so that fetal arterial oxygen tension fell significantly from 2.86 +/- 0.12 kPa (mean +/- SEM) to 1.55 +/- 0.04 kPa. The ewes were returned to normoxia, and monitoring was continued for 1 h. Fetal heart rate, arterial blood pressure, and femoral arterial blood flow (intact fetuses only) were recorded, and arterial pH, blood gases, and lactate were measured. Urine collected via a bladder catheter was analyzed for organic acids and hypoxanthine with gas chromatography-mass spectrometry. In intact fetuses, hypoxia increased excretion of hypoxanthine and several organic acids, notably lactic acid and intermediates of valine catabolism. Changes were apparent by 15 min, significant by 45 min, and maximal after reoxygenation. In denervated fetuses, there were small, significant, increases in organic acids and hypoxanthine by 45 min of hypoxia, but there was no surge in excretion posthypoxia. Hypoxia caused a large, significant, fall in femoral arterial blood flow in intact fetuses. We conclude that the extent of the reflex peripheral vasoconstriction, particularly in skeletal muscle, determines the amount of organic acid and hypoxanthine excretion and may explain similar biochemical disturbances after birth asphyxia. Urinary lactic acid measurement has a potential value for grading birth asphyxia.     

Mechanistic comparison of artificial-chaperone-assisted and unassisted refolding of urea-denatured carbonic anhydrase B

The serine protease thrombin is a key enzyme in the control of blood coagulation and displays numerous other effects on platelet, endothelial and smooth muscle cell function. The pre-eminence of thrombin in the coagulation cascade has made the enzyme a popular drug target in the search for more clinically acceptable and safe anti-coagulants. This concept has been particularly strengthened by the demonstration that direct inhibitors of thrombin such as Revasc are clinically effective. A number of low molecular weight thrombin inhibitors have now been described in the literature although to date because of their inherent low bioavailability compounds have been limited to the parenteral route of administration. The introduction of appropriate pharmacokinetic properties into these first generation thrombin inhibitors has been problematic despite intensive research in this area. However, the first pre clinical examples of direct thrombin inhibitors possessing good oral bioavailability is now emerging. This review updates current developments in the progress towards the discovery of orally available thrombin inhibitors and suggests that the first clinical validation of drugs from this field is imminent.     

Effect of the vaccines for children program on inner-city neighborhood physicians

PURPOSE: Atorvastatin (Lipitor) was developed as an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase for treatment of serum lipid disorders. Other reductase inhibitors (RIs) induce cataracts in dogs exposed to relatively high levels of the drugs for extended periods of time. The purpose of these studies was to assess the cataractogenic potential of atorvastatin, when administered for up to 2 years in beagle dogs. METHODS: Atorvastatin was administered at doses up to 150 mg/kg/day in 2-week, 13-week or 104-week studies. A 52-week interim sacrifice and a reversal group in which dosing was terminated at week 52 and the dogs sacrificed at week 64, was included in the 104-week study. RESULTS: Serum cholesterol was significantly lowered in all studies. No clinical or histologic evidence of drug-induced cataracts was found in any study. Lens biochemical analyses in the 13-week study revealed no statistically significant changes in lenticular weight, reduced or oxidized glutathione content, adenosine nucleotide content, glucose-6-phosphate dehydrogenase activity or phosphofructokinase activity in any treatment group. Modest (11-17%) and transient decreases in lens protein, potassium and glucose content were noted in the 13-week study and at week 52 (glucose only) in the 104-week study, at the doses > or = 40 mg/kg. CONCLUSIONS: These studies demonstrated that, in spite of marked reduction in serum cholesterol, atorvastatin was not cataractogenic in dogs at any tested dose. We conclude that atorvastatin differs from other RIs in this regard.     

Assessing information needs and instrument availability for a pressurized water reactor during severe accidents

A five-step methodology was developed to evaluate information needs for nuclear power plants under accident conditions and the availability of plant instrumentation during severe accidents. Step 1 examines the credible accidents and their relationships to plant safety functions. Step 2 determines the information that personnel involved in accident management will need to understand plant behavior. Step 3 determines the capability of the instrumentation to function properly under severe accident conditions. Step 4 determines the conditions expected during the identified severe accidents. Step 5 compares the instrument capabilities and severe accident conditions, to evaluate the availability of the instrumentation to supply needed plant information. This methodology was applied to a pressurized water reactor with a large dry containment and the results are presented. A companion article describes application of the methodology to a boiling water reactor with a Mark I containment.