O2A: One-Shot Observational Learning with Action Vectors.

We present O2A, a novel method for learning to perform robotic manipulation tasks from a single (one-shot) third-person demonstration video. To our knowledge, it is the first time this has been done for a single demonstration. The key novelty lies in pre-training a feature extractor for creating a perceptual representation for actions that we call "action vectors". The action vectors are extracted using a 3D-CNN model pre-trained as an action classifier on a generic action dataset. The distance between the action vectors from the observed third-person demonstration and trial robot executions is used as a reward for reinforcement learning of the demonstrated task. We report on experiments in simulation and on a real robot, with changes in viewpoint of observation, properties of the objects involved, scene background and morphology of the manipulator between the demonstration and the learning domains. O2A outperforms baseline approaches under different domain shifts and has comparable performance with an Oracle (that uses an ideal reward function). Videos of the results, including demonstrations, can be found in our: project-website.

The effect of plasmapheresis on blood pressure in voluntary plasma donors.

BACKGROUND AND OBJECTIVES: Donor plasmapheresis involves the removal of a weight-adjusted volume of plasma and the return of cellular components to the donor. Although plasma volume generally returns to normal, some residual effect on vital signs may be possible. This analysis was performed to determine the possible effects of plasmapheresis on blood pressure. MATERIALS AND METHODS: A 16-week study was conducted to evaluate the effects of plasma donations on cholesterol levels in healthy donors. From this study, the vital signs obtained prior to donation were analysed using statistical and dynamic analytical predictive models. RESULTS: Preliminary analyses revealed a change in systolic and diastolic blood pressure from the corresponding baseline values (Pearson Coefficient -0.44 and -0.47, respectively). Statistical models predicted a marked decrease in systolic and diastolic blood pressure following multiple donations in donors with baseline pressure in the Stage 2 hypertension range with less pronounced decreases predicted in Stage 1 donors. Little or no change in blood pressure was predicted in donors with baseline normal blood pressure or prehypertension. Dynamic models including time between donations supported these results and predicted a recovery period of about 14 days without donation in donors with Stage 2 baseline levels. CONCLUSIONS: Results suggest that systolic and diastolic blood pressure may be decreased following plasmapheresis used for plasma donations at intervals of <14 days in donors with high baseline blood pressure levels.

Prospective multicentre study of the effect of voluntary plasmapheresis on plasma cholesterol levels in donors.

BACKGROUND AND OBJECTIVES: LDL apheresis is used to treat patients with familial hypercholesterolaemia, and low-volume plasmapheresis for plasma donation may similarly lower cholesterol levels in some donors. This study was designed to assess the effect of plasmapheresis on total, LDL and HDL cholesterol levels in a plasma donor population. MATERIALS AND METHODS: This was a prospective, unblinded longitudinal cohort study in which a blood sample was obtained for analysis before each donation. Data from 663 donors were analysed using a multivariable repeated measures regression model with a general estimating equations approach with changes in cholesterol as the primary outcome measure. RESULTS: The model predicted a significant decrease in total and LDL cholesterol for both genders and all baseline cholesterol levels (P < 0.01). The greatest total cholesterol decreases (women, -46.8 mg/dL; men, -32.2 mg/dL) were associated with high baseline levels and 2-4 days between donations. Small but statistically significant increases (P ≤ 0.01) in HDL cholesterol were predicted for donors with low baseline levels. CONCLUSIONS: These results suggest that, in donors with elevated baseline cholesterol levels, total and LDL cholesterol levels may decrease during routine voluntary plasmapheresis.

Nosocomial transmission of Cupriavidus pauculus during extracorporeal membrane oxygenation.

Patients undergoing extracorporeal membrane oxygenation (ECMO) are at increased risk of infection. We present the first known report of nosocomial infection with Cupriavidus pauculus attributable to contamination from ECMO equipment and describe the measures taken to halt subsequent infections. A cluster of infections in ECMO patients should prompt team members to consider contamination of equipment with environmental pathogens as a possible cause.

Fluosol DA-20 in the treatment of severe anemia: randomized, controlled study of 46 patients.

We evaluated the safety and efficacy of Fluosol DA-20% (FDA) as a blood substitute in the treatment of severe anemia. Thirty-six patients received either FDA (n = 21) or crystalloid/hydroxyethyl starch (CHS) (n = 15) as part of a randomized, controlled trial. Ten patients received FDA as part of a humanitarian protocol. All were Jehovah's Witnesses who refused transfusion, had bled recently, and had average Hgb levels of 4.3 g/dl. After pulmonary artery catheter insertion, each patient was infused with CHS to attain a pulmonary artery wedge pressure (WP) of 10 to 18 mm Hg. FDA was given as a one-time dose of 30 ml/kg. Data were collected at baseline, 12, 24, and 48 h. None of the patients with negative reactions to a 0.5-ml test dose of FDA had adverse reactions to the subsequent infusion. The plasma or dissolved component of oxygen content was significantly higher in the FDA group at 12 h (FDA group 1.58 +/- 0.47 ml/dl, control group 1.01 +/- 0.31 ml/dl, p less than .02, t-test). Nineteen patients died: 12 (37.5%) FDA, seven (46.6%) control. The difference was not significant. We conclude the following: a) FDA can be given safely to severely anemic patients in doses of 30 ml/kg; b) FDA significantly increased the dissolved component of oxygen content after 12 h but the effect did not persist; c) severely anemic patients can survive without transfusion although mortality is high. In this study, inability of FDA to sustain increased oxygen content was due in part to the rapid elimination of FDA and also to the limited amount given.(ABSTRACT TRUNCATED AT 250 WORDS)

Compound interactions effects of plant antioxidants in combination with carbaryl on performance ofTrichoplusia ni (Cabbage Looper).

Plant chemicals naturally exist in complex mixtures, which can interact either additively, synergistically, or antagonistically. We investigated the potential interactions of three naturally occurring antioxidants- nordihydroguaiaretic acid (NDGA), safrole, and α-tocopherol-with the general insecticide carbarayl to affect the performance of cabbage looper larvae (Trichoplusia ni). The cabbage looper is known to produce a mixed-function oxidase enzyme system in response to the presence of carbaryl. We proposed that plant antioxidants would interfere with enzymatic oxidation, enhancing the susceptibility of this insect to carbaryl. Insects were fed artificial diets containing each antioxidant alone or in pairwise combinations with the insecticide carbaryl to test for their effects on the insect's nutritional measurement indices. The three antioxidants tested were not equally effective individually against insect survivorship and interacted differentially in combination with the insecticide. The nutritional indices were measured on insects fed diets containing the chemicals at nonlethal doses. Insects fed 0.001 % wet wt NDGA diets grew 1.62 times less, and had gross and net conversion efficiencies reduced 3.20 and 3.63 times, respectively, compared to the control larvae. Carbaryl (0.002% wet wt) in combination with NDGA acts as an antagonist to the effects mentioned above, while safrole (1 × 10(-4) wet wt) had an additive effect when combined with the insecticide, reducing 1.76 times larval relative growth rate and efficiency of conversion of ingested food in respect to the control. The larvae fed significantly more (1.2 times) on both insecticide and safrole diets than on the controls or their combined diets. Larvae fed α-tocopherol alone or in combination with carbaryl had similar growth and conversion efficiencies as controls. We conclude that the effects of different combinations of compounds cannot be predicted a priori and must be determined experimentally.

Effects of controlled-released morphine on quality of life for cancer pain.

Oncology nursing is concerned with pain relief and overall Quality of Life (QOL). The purpose of this study was to determine the effects of controlled-release morphine on QOL for patients with cancer. Eighty-three subjects were randomly assigned in a clinical trial of short-acting versus controlled-release analgesia (MS Contin, Purdue Frederick Co., Norwalk, CT). Data was collected in a repeated measures design every 2 weeks for 6 weeks yielding a total of 240 visits. Five instruments were used to assess QOL, pain, and functional status. Study findings indicate improved pain management with controlled-release MS Contin and important nursing implications for the management of analgesia-induced gastrointestinal symptoms. Through appropriate pain management with pain therapies such as controlled-release analgesia, nurses can greatly enhance QOL for the patient with cancer.

Quality of life as an outcome variable in the management of cancer pain.

Valid measurement tools are needed by oncology researchers to help in the evaluation of the effectiveness of pain relief methods used in the treatment of cancer patients. A study was conducted to assess the validity and reliability of a tool designed to evaluate quality of life as a measure of pain management outcome in the individual patient. Items in the tested quality of life survey represented the areas of psychologic well-being, physical well-being, general and specific symptom control, and degree of social support. Using the test instrument, two oncology nurses interviewed subjects in three groups, each consisting of 50 subjects: cancer patients with pain, cancer patients without pain, and subjects with no cancer. Statistical analysis of the interview results revealed that the instrument has test-retest reliability, internal consistency, and interrater reliability, as well as content and construct validity for the major factors, psychologic well-being, worry, and nutrition. Further revision of the instrument is needed to restructure its subscales. The quality of life tool will enable researchers to evaluate a treatment regarding not only its effect on pain intensity but also its impact on the total individual.

Ecological tannin assays : Evaluation of proanthocyanidins, protein binding assays and protein precipitating potential.

Estimations of condensed tannin content are generally based on calibration standard curves from Quebracho condensed tannins. We generated calibration standard curves from eight Sonoran Desert species for comparison with estimates of tannin concentrations derived from the Quebracho standard curve. Estimates of leaf tannin concentrations of each of the eight species using each species standard curve differed significantly with the estimates given by the Quebracho standard curve. Standard curves constructed from tannins from different individuals of three of the species varied significantly between, but not within, species. The efficiency of precipitation of protein bovine serum albumin (BSA) by each different tannin varied up to a factor of fifty for tannins of different species. Ordering species from highest to lowest based on tannin concentrations or binding efficiencies gave two different ranks. We argue that concentration or efficiency alone do not describe adequately tannin ecological activity. Instead, we suggest combining tannin concentrations and binding efficiencies to measure the protein precipitating potential of a leaf. Leaf protein precipitating potential is a more ecologically realistic parameter, we feel, for between-species comparisons than tannin content or binding efficiencies alone.

Effects of intravenously infused Fluosol-DA 20% in rats.

Rats were injected with a fractionated 50 ml/kg dose of Fluosol-DA 20% with and without exposure to 100% oxygen. Animals were killed at 24, 43, 92, and 183 days post-treatment and samples taken for hematological, hepatic enzyme, histological, and perfluorochemical analyses. There were no significant differences in hemograms or hepatic enzyme findings between treatment and control groups. Differences in organ weights and histology were a result of perfluorochemical (PFC) accumulation in the tissues of treated animals. All changes were reversible. There were no effects from breathing high oxygen levels in either treatment or control animals.

Use of chemical variation and predation as plant defenses byEncelia farinosa against a specialist herbivore.

Larvae of the monophagous herbivore,Trirhabda geminata, selectively eat particular plants and plant parts of its natural host,Encelia farinosa. Measurements of leaf damage and larval positions on branches through time support this observation. Time-lapse movie photography revealed that larvae are sufficiently mobile to search most of a plant in a 48-hr period and that aggregations were the result of larval activity and not directly the result of oviposition. Experiments withT. geminata larvae on artificial diets containing a range of natural concentrations of chemical extracts fromE. farinosa leaves showed that the larvae grew significantly slower and had a lower overall survivorship at the high concentration. Combining the results of all choice tests, larvae appeared unable to distinguish between high- and low-concentration agar diets. Considered individually, larval preferences for natural production concentrations changed as the season progressed. Early-season larvae preferred low-concentration leaves, while late-season larvae preferred high-concentrations. Measurements of chemical and nitrogen content of leaves selected by larvae in the field confirmed this pattern. Percent parasitism in field-collected larvae increased with season as the larval population decreased. This combination of slowed growth and increasing parasitism and predation is a putative defense strategy ofEncelia farinosa to prevent adaptation by a specialist herbivore to the total range of compounds elaborated.

Effects of Clostridium botulinum toxins on infant and adult mice.

Toxic supernatants of many Clostridium botulinum type B isolates from various sources, especially those of isolates obtained from cases of infant botulism, appeared to more toxic in infant mice than in adult mice. The significance of this finding in diagnostic situations is discussed.

Action of Escherichia coli enterotoxin: adenylate cyclase behavior of intestinal epithelial cells in culture.

Heat-labile enterotoxin preparations obtained from two enteropathogenic strains of Escherichia coli of porcine and human origin were shown to stimulate adenylate cyclase activity of human embryonic intestinal epithelial cells in culture. Comparable results were also obtained when cholera toxin was used. The degree of enzyme stimulation was proportional to the concentration of enterotoxin. Similar preparations from two strains of non-enterotoxigenic E. coli had no effect on adenylate cyclase activity. Cells exposed to enterotoxin could be washed after 1 min of contact time without altering the subsequent course of maximum adenylate cyclase activity, which was maintained for at least 18 h at 37 C. During long periods (18 h) of tissue culture incubation, the determination of adenylate cyclase activity was 200- to 300-fold more sensitive than quantitating fluid accumulation in the adult rabbit ileal loop model. Decreasing the incubation time appreciably reduced the sensitivity of the epithelial cells to enterotoxin. E. coli enterotoxin is an effective activator of nonintestinal adenylate cyclase systems. Treatment of KB and HEp-2 cell lines with enterotoxin also resulted in significant enzyme stimulation. The intestinal epithelial cell tissue culture model provides a sensitive homogenous biological system for studying the response of intestinal adenylate cyclase to enterotoxin while eliminating the numerous cellular and tissue components present in the ligated ileal loop model.

Membranes of Bacillus stearothermophilus: factors affecting protoplast stability and thermostability of alkaline phosphatase and reduced nicotinamide adenine dinucleotide oxidase.

Protoplasts of Bacillus stearothermophilus NCA 1503-4R are resistant to osmotic rupture and are not sensitive to mechanical manipulation. Protoplast stability is maintained by divalent cations. The thermostability of protoplasts is enhanced when the cells are grown at elevated temperatures. The membrane content of the cell and the protein-to-lipid ratio of the membrane increases as the growth temperature is increased. The membrane-bound nicotinamide adenine dinucleotide (reduced form) oxidase system from cultures grown at 70 C was more thermostable than the same enzyme system from cultures grown at 55 C. Alkaline phosphatase was resistant to thermal inactivation in the intact protoplast. The extent of this protection is dependent on protoplast stability.