A proposed design for a polarization-insensitive optical interferometer system with subnanometric capability

A bidirectional, fringe-counting, two-beam interferometer system is described that can be used for precision length measurement with any laser source that is adequately coherent for the application. The two electrical phase-quadrature signals required for bidirectional electronic counting are obtained from photodetectors at the two interferometer outputs. A thin metal film design for the beam-splitter coating introduces the required phase difference of nearly 90° for both the perpendicular and parallel polarization components. Electronic alignment and control are performed by a system used to continuously monitor the signals produced from the outputs and automatically process these signals to achieve the optimum performance from the interferometer. Interferometers using the technique require a limited amount of optical alignment and all of the electronic adjustments are automatically controlled by the electronic system. These instruments are economical to manufacture and easy to apply in practice, readily achieving subnanometric accuracy in the measurement of changes in optical path.     

Using random weights to train multilayer networks of hard-limitingunits

A gradient descent algorithm suitable for training multilayer feedforward networks of processing units with hard-limiting output functions is presented. The conventional backpropagation algorithm cannot be applied in this case because the required derivatives are not available. However, if the network weights are random variables with smooth distribution functions, the probability of a hard-limiting unit taking one of its two possible values is a continuously differentiable function. In the paper, this is used to develop an algorithm similar to backpropagation, but for the hard-limiting case. It is shown that the computational framework of this algorithm is similar to standard backpropagation, but there is an additional computational expense involved in the estimation of gradients. Upper bounds on this estimation penalty are given. Two examples which indicate that, when this algorithm is used to train networks of hard-limiting units, its performance is similar to that of conventional backpropagation applied to networks of units with sigmoidal characteristics are presented.     

Relationship among sex, imagery and exercise dependence symptoms.

There is limited research examining the physical (e.g., sex) and psychological correlates (e.g., imagery) of exercise dependence despite its harmful effects. The purposes of this study were to examine sex differences and the predictive validity of exercise imagery for exercise dependence symptoms. Participants were 408 university students who completed measures of exercise imagery, exercise behavior, and exercise dependence. The results indicated that men reported more exercise dependence symptoms than women. For the women, exercise behavior, appearance imagery, and energy imagery were positive predictors of exercise dependence symptoms. In contrast, for the men, exercise behavior and energy imagery positively predicted exercise dependence symptoms. Consistent with suggestions by C. Hall (1995), exercise imagery may be related to exercise dependence symptoms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Novel trabecular meshwork inducible glucocorticoid response mutation in an eight-generation juvenile-onset primary open-angle glaucoma pedigree

OBJECTIVE: This study aimed to update a large kindred with juvenile-onset primary open-angle glaucoma (POAG) first described in 1940 and to identify the underlying genetic cause of the disease. DESIGN: Molecular genetic study of a single kindred, including clinical examination, retrospective review of clinical and family history records, linkage analysis, and mutation screening. PARTICIPANTS: The retrospective review included 957 members of a single large family. The linkage study included 40 members of 1 branch of the family in which juvenile-onset POAG is segregating in an autosomal-dominant pattern. Mutation screening included 15 at-risk family members with juvenile-onset POAG, probands of 40 families with adult-onset POAG, probands of 11 additional unrelated juvenile-onset POAG families, and 43 unrelated normal control subjects. INTERVENTION: Clinical and family history records were obtained, ophthalmologic examinations were performed, and blood samples were drawn for use in genotyping. MAIN OUTCOME MEASURES: Allele sizes of microsatellite repeat genetic markers from the vicinity of the GLC1A glaucoma gene on chromosome 1q were assigned based on size fractionation of DNA fragments generated by polymerase chain reaction (PCR). Linkage was established by the method of lod scores. Mutations were identified by determination of the DNA sequence of PCR products amplified from the trabecular meshwork inducible glucocorticoid response (TIGR) gene. Glaucoma status for purposes of linkage and mutation analysis was based on a combination of ophthalmologic examination, clinical records, family history, and previously published information. For some individuals reported in the pedigree, but not included in the genotyping studies, less information was available as presented in the text and tables. RESULTS: Autosomal-dominant POAG was confirmed or reported for 78 members of an 8-generation family. Linkage analysis showed significant evidence for linkage of juvenile-onset POAG in one branch of the family to D1S452 (maximum lod score of 6.42 at a recombination fraction of 0.00) and other markers in the vicinity of the GLC1A gene on chromosome 1q. Screening of the TIGR gene identified a mutation that results in substitution of asparagine for isoleucine at codon 477 near the carboxyterminal end of the protein. CONCLUSIONS: The authors' findings strongly suggest that the juvenile-onset POAG locus in this family is the GLC1A locus and that the underlying cause of the disease is the IIe477Asn TIGR mutation that cosegregates with juvenile-onset POAG in one branch of this large family. Lack of samples from deceased individuals prevented the authors from determining whether reported adult-onset cases in this family could also be attributed to the IIe477Asn TIGR mutation. Absence of the IIe477Asn TIGR mutation from other juvenile- and adult-onset POAG families implies that this TIGR mutation is not a common cause of glaucoma.     

The small, methionine-rich chloroplast heat-shock protein protects photosystem II electron transport during heat stress

Evidence suggests that the small chloroplast heat-shock protein (Hsp) is involved in plant thermotolerance but its site of action is unknown. Functional disruption of this Hsp using anti-Hsp antibodies or addition of purified Hsp to chloroplasts indicated that (a) this Hsp protects thermolabile photosystem II and, consequently, whole-chain electron transport during heat stress; and (b) this Hsp completely accounted for heat acclimation of electron transport in pre-heat-stressed plants. Therefore, this Hsp is a major adaptation to acute heat stress in plants.     

Self-presentation in everyday interactions: Effects of target familiarity and gender composition.

Examined people's self-presentational motives in unstructured, everyday social interaction as a function of participants' gender similarity to, and general familiarity with, the targets of their self-presentations. Participants maintained a variant of the Rochester Interaction Record for 1 wk. For every interaction that lasted 10 min or more, they rated the degree to which they wanted to make each of 4 impressions (likable, competent, ethical, and attractive), how much they thought about the impressions others in the interaction formed of them, and how nervous they felt in the interaction. In general, participants' self-presentational motives were lower in interactions with highly familiar people of their own sex than they were either in interactions with less familiar people of their sex or in interactions with people of the other sex regardless of familiarity. When participants' interactions with only their 3 most familiar interactants were examined, self-presentational concerns decreased with familiarity in same-sex interactions but increased with familiarity in cross-sex interactions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sorption of organics by Selenastrum capricornutum

The sorption of eight organic compounds by a representative green alga, Selenastrum capricornutum, was determined by gas-liquid chromatography using a series of linear model experiments. The log₁₀ bioconcentration factors (BCF), defined as the ratio of the concentration on in the algae to the concentration in the aqueous medium, are as follows: benzene, 3.32; toluene, 3.18; chlorobenzene, 3.69; 1,2-dichlorobenzene, 4.17; naphthalene, 4.10; phenanthrene, 4.38; di-n-butylphthalate, 4.36 and pyrene, 4.56. The relation of log₁₀ BCF correlation with log₁₀ octanol-water partition coefficient was determined as log₁₀ BCF = 0.46 log₁₀ P + 2.36.     

A comparative study of midazolam to meperidine/promethazine as an IM sedative technique for the pediatric dental patient

This study evaluated the efficacy and safety of midazolam (0.2 mg/kg) as an IM sedative agent in the pediatric population as compared to the standard IM meperidine (2.0 mg/kg)/promethazine (1.0 mg/kg) sedation technique. Ten pediatric dental patients, ASA Class I, were evaluated in this double-blind, randomized, crossover study. The patients ranged in age from two to four years. Vital signs, sedation levels, and anxiety levels were evaluated. Midazolam was shown to be safe, but the inferior drug compared to the standard IM meperidine/promethazine sedation technique.