A Lens-Calibrated Active Marker Metrology System

This paper presents a prototypical marker tracking system, MT, which is capable of recording multiple mobile robot trajectories in parallel for offline analysis. The system is also capable of providing trajectory data in realtime to agents (such as robots in an arena) and implements several multi-agent operators to simplify agent-based perception. The latter characteristic provides an ability to minimise the normally expensive process of implementing agent-centric perceptual mechanisms and provides a means for multiagent "global knowledge" (Parker 1993)

Influence of Motivation on the Efficacy of Natural Family Planning

Purpose: Mutual motivation is recognized as essential for effective behavioral methods of family planning. Few studies have studied this factor in family planning efficacy. The purpose of this study was to determine the influence of mutual motivation on unintended pregnancy rates of couples who used natural family planning (NFP) methods to avoid pregnancy. Study Design and Methods: Using an online taught NFP method, 358women and ( their male partners) indicated “how much” and “how hard” they wished to avoid pregnancy on a scale of 0-10 before each menstrual cycle charted over 12 month of use. This motivation scale is used in the National Survey of Family Growth as a measure of motivation. All pregnancies were verified with an online pregnancy evaluation and urine based pregnancy test. A combined motivation score was used in analysis. Results: There were 28 pregnancies among the low motivation participants (N=60) and 16 among the high motivation participants (N=298). At 12 months of use, there were 75 pregnancies per 100 users for the low motivation group and only 8 for the high motivation group. There was an 80% greater likelihood of a pregnancy with the low motivation group (χ2 = 25.5, p \u3c .001) OR = 1.80; 95% CI = 1.61-1.90). Clinical Implications: High motivation to avoid pregnancy by both the female user of a behavioral method of family planning and her male partner is required for high efficacy. Assessing motivation of both the woman and her male partner before prescribing NFP methods is recommended

The Crystal Structure of Ethylenebis(biguanidine)nickel(II) Dichloride Monohydrate

The crystal structure of ethylenebis(biguanidine)nickel(II) dichloride monohydrate, Ni(C_6H_(16)N_(10))Cl_2.H_2O, has been determined and refined on the basis of three-dimensional intensity data collected on an automated diffractometer. The crystals are monoclinic, space group P2_1/c, with cell dimensions ɑ = 6-911, b = 11·678, c = 18·055 Å, β = 101·39°; there are four molecules in the cell. The structure was determined by Patterson methods and refined by least-squares to an R index of 0·048 and a goodness-of-fit of 1·11 for 2879 reflections of non-zero weight. The resulting standard deviations in the atomic positions are about 0·002-0·003 A for the C, N and 0 atoms, 0·02-0·03 Å for the H atoms and less than 0·001 Å for Ni and CI-. The organic ligand is tetradentate and forms a square-planar array about the central nickel atom; the average Ni-N distance is 1 ·865 Å. Chemically equivalent bonds are equal in length within experimental error, and the bond distances have been satisfactorily correlated with molecular-orbital and valencebond descriptions of the cation. All available hydrogen atoms are involved in hydrogen bonds to chloride ions or water molecules. An interesting feature is that, in spite of considerable double-bond character in the C-N bonds, many of the hydrogen atoms are displaced appreciably from the plane of the cation toward the hydrogen-bond acceptors; the bonding about the nitrogen atoms thus becomes pyramidal

Law, Language, and Forensic Psychiatry

Dr. Thomas Szaz, a controversial figure in psychiatry today, attacks the use of a medical model to explain abnormal behavior. The authors analyze Szaz\u27 views and their implications on the issues of the insanity plea, competency to stand trial, the right to medical treatment, involuntary civil commitment, and victimless crimes