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In this paper, we provide the first demonstration that a humanoid robot can learn to walk directly by imitating a human gait obtained from motion capture (mocap) data without any prior information of its dynamics model. Programming a humanoid robot to perform an action (such as walking) that takes into account the robot's complex dynamics is a challenging problem. Traditional approaches typically require highly accurate prior knowledge of the robot's dynamics and environment in order to devise complex (and often brittle) control algorithms for generating a stable dynamic motion. Training using human mocap is an intuitive and flexible approach to programming a robot, but direct usage of mocap data usually results in dynamically unstable motion. Furthermore, optimization using high-dimensional mocap data in the humanoid full-body joint space is typically intractable. We propose a new approach to tractable imitation-based learning in humanoids without a robot's dynamic model. We represent kinematic informati...

Decades after its introduction, dilatation and evacuation (D&E) is still not universally offered by gynaecologists who provide second trimester abortion. Three lines of evidence point to D&E as the preferred method for most women. First, the uterus has evolved to expel its contents early and late in pregnancy, not in the middle. Hence, induction of labour with medical abortion forces the uterus to perform a task it is not designed to do. Second, cohort studies and randomised, controlled trials over the past 30 years have consistently shown that D&E is safer and more effective than labour induction abortion, regardless of the abortifacient used. Third, the ethical principles of beneficence, autonomy and justice require that D&E be routinely offered by gynaecologists who perform second trimester abortions. The uneven geographical availability of D&E may stem from lack of information, lack of requisite equipment and training, or lack of motivation. According to the principles of evidence-based medicine and bioethics, these barriers to better care for women can and should be overcome.

The effects of three ratios of Ca/(Ca + K) and three rates of NO3‐N on ion ratios in plants grown in soil and nutrient culture are reported. Plant uptake parameters, based on nutrient culture studies, together with soil chemical parameters, were used in a multiple‐ion uptake model to calculate the cumulative, uptake of individual ions. These calculated uptakes were then used to derive relevant ratios for comparison with those measured in plants grown in soil in a growth chamber. The results illustrate that the ionic ratios based on the model are well correlated with the measured plant ratios. Regressions of plant ratios on model ratios were calculated; the intercepts were not zero and the slopes were not one. The discrepancies between measured and model ratios were probably a consequence of deficiencies in the model and unmeasured plant uptake parameters. The results illustrate that the model is a useful way to summarize data and to generate hypotheses.

Understanding the factors influencing cation accumulation by plants is needed, because of the importance of calcium (Ca) and magnesium (Mg) in both plant and animal nutrition. To determine the effect of anion levels and the proportion of Ca in solution on Ca, Mg, and potassium (K) accumulation by winter wheat forage (Triticum aestivum L. ‘Centurk'), seedlings were grown in nutrient solution and soil, at three levels of nitrate and three Ca/(Ca+K) mole ratios (0.2, 0.5, 0.8). In solution culture, increasing nitrate levels [added as Ca(NO3)2 and KNO3] significantly increased total nitrogen (N) and Ca concentrations in the shoots, but had no significant effect on K concentrations in the shoots. As a result, increasing nitrate levels significantly depressed equivalent ratios of K/(Ca+Mg) in the shoots, thus reducing the tetany hazard of wheat forage. In soil, increasing nitrate levels [applied as Ca(NO3)2 and KNO3] significantly increased nitrate, Ca, Mg, and K concentrations in the bulk soil solutio...

Pregnancy is a sexually-transmitted condition, which if unwanted can lead to sociopathic outcomes. For women who choose to terminate an unwanted pregnancy, the preferred approach is legal abortion in the first trimester by suction curettage. This procedure compares favorably in efficacy and safety with pennicillen for the treatment for gonorrhea. Placed in this perspective, legal abortion should be viewed as an effective and safe treatment for the condition of unwanted pregnancy.