Fano resonance resulting from a tunable interaction between molecular vibrational modes and a double continuum of a plasmonic metamolecule.

Coupling between tunable broadband modes of an array of plasmonic metamolecules and a vibrational mode of carbonyl bond of poly(methyl methacrylate) is shown experimentally to produce a Fano resonance, which can be tuned in situ by varying the polarization of incident light. The interaction between the plasmon modes and the molecular resonance is investigated using both rigorous electromagnetic calculations and a quantum mechanical model describing the quantum interference between a discrete state and two continua. The predictions of the quantum mechanical model are in good agreement with the experimental data and provide an intuitive interpretation, at the quantum level, of the plasmon-molecule coupling.

The dynamics of velocity adaptation in human vision.

Since Barlow and Hill's classic study of the adaptation of the rabbit ganglion cell to movement [1], there have been several reports that motion adaptation is accompanied by an exponential reduction in spike rate, and similar estimates of the time course of velocity adaptation have been found across species [2-4]. Psychophysical studies in humans have shown that perceived velocity may reduce exponentially with adaptation [5,6]. It has been suggested that the reduction in firing of single cells may constitute the neural substrate of the reduction in perceived speed in humans [1,5-7]. Although a model of velocity coding in which the firing rate directly encodes speed may have the advantage of simplicity, it is not supported by psychophysical research. Furthermore, psychophysical estimates of the time course of perceived speed adaptation are not entirely consistent with physiological estimates. This discrepancy between psychophysical and physiological estimates may be due to the unrealistic assumption that speed is coded in the gross spike rate of neurons in the primary visual cortex. The psychophysical data on motion processing are, however, generally consistent with a model in which perceived velocity is derived from the ratio of two temporal channels [8-14]. We have examined the time course of speed adaptation and recovery to determine whether the observed rates can be better related to the established physiology if a ratio model of velocity processing is assumed. Our results indicate that such a model describes the data well and can accommodate the observed difference in the time courses of physiological and psychophysical processes.

The Adolescent Family Life Program as a prevention measure.

Adolescent pregnancy and parenthood remain a source of considerable concern, not only due to the well-documented adverse consequences of teenage pregnancy, but also because of certain trends that emerged during the seventies. Survey results showed a dramatic upsurge in premarital sexual activity, while pregnancies and sexually transmitted diseases rose. Out-of-wedlock births also increased. The Adolescent Family Life Program is a new Federal Government effort to deal with the resultant complex of problems.THE PROGRAM HAS TWO MAJOR THRUSTS: (a) preventing adolescent pregnancies by emphasizing the strategy of reaching adolescents before they become sexually active and (b) preventing various negative consequences of pregnancy that often occur among adolescent parents and their off spring. The Program is funding projects that demonstrate and evaluate innovative services in order to obtain knowledge about what works best under given circumstances in both instances. Later, proven models will be made available for adaptation by local communities.Education about the responsibilities of sexuality and parenting will be among the prevention services encouraged in the funded projects. Care services to parenting adolescents include pre and postnatal care, nutrition counseling, continuing education, and vocational services.Through its research component, the Adolescent Family Life Program also has the potential for contributing to an understanding of how to prevent adolescent pregnancies and their adverse consequences. Research projects may encompass the causes and consequences of adolescent sexual relations, use of contraceptives, pregnancy, and child-rearing.Family involvement is a consistent theme in all efforts of the Adolescent Family Life Program. It is anticipated that results of the projects funded by the Program will illuminate ways to incorporate the family into a successful partnership aimed at preventing the problems of adolescent pregnancy.

Legibility and completeness of physicians' handwritten medication orders.

OBJECTIVE: To assess handwritten medication orders for legibility and completeness, legibility of physician signatures, and presence of date and time the orders were written. DESIGN: Descriptive. SETTING: Three patient care units in one hospital in Texas. SAMPLE: One hundred seventy-six medication orders and 55 signatures by 36 different physicians for 39 patients. METHODS: Six experienced nurses evaluated medication orders and signatures for legibility using a rating scale developed for the study. Completeness of medication orders and presence of date and time were determined. RESULTS: Twenty percent [corrected] of the medication orders and 78% of the signatures were illegible or legible with effort. Twenty-four percent of the medication orders were incomplete. Date was omitted on 18% of the medication orders, and time was missing on 58%. CONCLUSION: Difficult-to-read and incomplete medication orders continue to be an important system problem that can increase risk for medication errors and patient harm. Good penmanship and complete orders are unrealistic goals without system support.

Cochlear implant extrusion in a young child--a preventive procedure.

A Cochlear Mini System 22 Channel cochlear implant extruded through the skin of a young girl. The implant was saved by use of a transposition flap. Extrusion appeared to be due to pressure necrosis from the implant on the overlying tissues. It is believed that this problem can be prevented by angulation of the implant before insertion so that it conforms to the curvature of the skull, so avoiding pressure on the tissues. The method of angulation is described.

A survey for resistance in cattle ticks to acaricides.

A survey was made from late 1976 to late 1977 to determine the extent of resistance to acaricides in the cattle tick Boophilus microplus in Queensland. Questionnaires and requests for samples of ticks were forwarded to more than 900 randomly selected stock owners in the tick infested area which had been divided into 4 regions. Far North, Coastal North, Coastal Cental and South East. The response measured by the number of tick samples tested was 43%. The prevalence of resistance to organophosphorus (OP) compounds was highest in South East where 96% of the farms had OP-resistant ticks and 95% had the Biarra strain and lowest in Far North where 12% of the farms had OP-resistant ticks and 10% had the Biarra strain which was the predominant one in all regions. The highest percentages of the Ridgelands strain (35%) and the Tully strain (30%) occurred in Coastal North. The South East had the highest percentage of Mt Alford (30%). Although chlorinated hydrocarbons were banned for use in control of ticks in 1962, 49% of the farms in South East had some ticks resistant to dieldrin but in Far North it was only 2%. DDT-resistant ticks, which because of cross resistance to synthetic pyrethroids will affect the future use of this group, were present on 8% of the farms in both Coastal North and Coastal Central and 3% in South East and Far North. No resistance to the amidines, chlordimeform, chloromethiuron or amitraz was found.

The public health impact of dog attacks in a major Australian city.

OBJECTIVE: To examine the impact of dog attacks by determining the incidence and risk factors for dog attacks. DESIGN: Injury surveillance data on dog attacks for a major metropolitan hospital were converted to incidence rates using 1991 census figures for the hospital catchment area and combined with data on community attitudes and experiences derived from a large community survey. SETTING: Queen Elizabeth Hospital (tertiary referral hospital), Adelaide, South Australia, January 1990 to July 1993. PARTICIPANTS: 356 victims of dog attacks who presented to the emergency department and 3093 respondents to the 1992 South Australian Health Omnibus Survey. MAIN OUTCOME MEASURES: Rates of dog attack by age and sex of the victim, hospital presentation and admission; differences in the representation of various dog breeds in attacks. RESULTS: About 6500 people are injured in Adelaide each year as a result of dog attacks and about 810 seek hospital treatment (7.3 per 10,000 people per year). Children aged 0-4 years were attacked and required hospital treatment twice as often as adults aged 21-59 years, and men aged over 76 years twice as often as men aged 36-75 years. Males were more at risk of attack than females for all age groups. Hospital admission rates were five times higher for the elderly (95% confidence interval [CI], 2.3%-10.2%) and seven times higher for children 12 years and under (95% CI, 3.4%-15.1%) compared with people aged 13-59 years; 90% of children were admitted because of head and facial bites. The risk of attack from german shepherds, bull terriers, blue/red heelers, dobermans and rottwellers was four to five times higher than for other common breeds. CONCLUSIONS: The public health implications of dog attacks are significant and there needs to be increased awareness of the risks to young children. Potential interventions to reduce the incidence of dog attacks vary from strict controls on high-risk breeds to mandatory leashing to a "user pays" liability insurance proposal.

Preventing falls in the elderly at home: a community-based program.

OBJECTIVE: To analyse the effectiveness of an ongoing program for reducing the risk of falls in the elderly in their homes. DESIGN: Retrospective questionnaire survey of the number of falls in the 12 months before home modifications were installed. Participants were followed up 12 months later to determine the number of falls since home modifications. SETTING: Major city, November 1993 to July 1995. PARTICIPANTS: Healthy elderly people recruited at presentations made to gatherings of elderly people about the risks of falls in the home. INTERVENTION: A free home safety inspection and simple home modifications, such as grab-rails and non-slip floor surfaces, were offered at subsidized prices. MAIN OUTCOME MEASURES: Number of falls in the 12 months before and after home modifications. RESULTS: Nearly 4000 elderly people agreed to have a home safety inspection and, of these 90% agreed to have their homes modified. Of the first 305 participants (mean age 74 years) for whom it had been 12 months since modifications 69 (22.6%) had reported having fallen at least once in 12 months before modifications. In the 12 months after modifications, 29 participants (9.5% reported at least one or more falls--a 58% reduction (95% confidence interval [Cl], 37%-72%). The total number of falls decreased from 121 to 45--a 63% reduction (95% Cl, 50%-73%). There was a significant decrease in falls in the 61-65, 66-70, 71-75 and 81-85 years age groups (P< 0.05). CONCLUSIONS: The risk of falling in the elderly can be lowered by more than a half by simple modifications to the home. Behavioural change, as well as environmental change, is important to the success of falls-prevention programs.

Aging in the 1990s and beyond.

The future of aging persons in an aging society will depend equally upon the exogenous factors of the society and upon our attitudes and behaviors. The changes in the numbers and proportions of elderly create constraints and pressures upon resources and services. These incentives for decision-making are then mirrored in our behaviors and attitudes about aging, and about the elderly. The role of the aging person is undergoing re-evaluation--from "retired," "grandparent," and "being seen and not heard" in family matters, to a more active and participative role. Retirement to (rather than from) second careers, political participation, community leadership, and new creativity in the choices of leisure roles are the new norms for aging persons. The changing demographic profile motivates us to anticipate new approaches to health care for an aging population. In the face of increasing longevity, the primary concern to be addressed is the development and administering of a system of services for the chronically ill. These health services must be coordinated to meet a range of needs from nutrition to hospice care, and yet to protect the individual and personal rights of the individual and to respond to the changing attitudes of the elderly as well as toward the elderly.

Storage of spatially specific threshold elevation.

The decay of several visual aftereffects may be prolonged by interposing a period of light-free or pattern-free viewing between adaptation and testing. We demonstrate that this storage phenomenon can be observed using the threshold elevation aftereffect that follows inspection of a high-contrast grating pattern. Control experiments comparing thresholds for vertical and horizontal gratings after adaptation to a vertical grating reveal that the stored aftereffect, like its unstored counterpart, is pattern-selective. Storage is equally pronounced with stimuli that are detected by pattern-analyzing or movement-analyzing visual channels. Unlike other aftereffects, the threshold-elevation aftereffect requires that the storage period be light-free; no storage is seen if a blank field is inspected between adaptation and testing. The results are discussed with respect to the nature of visual aftereffects, and possible cognitive or physiological models of storage.

Metabolism of [14C] amitraz in larvae of Boophilus microplus.

Amitraz, 1, 5-di(2, 4-dimethylphenyl)-3-methyl-1, 3, 5-triazapenta-1, 4-diene, labelled with 14C in the 2-methyl groups was applied to B. microplus larvae by an immersion technique. The chemical penetrated readily but never appeared in large amounts internally due to rapid cleavage to N-2, 4-dimethylphenyl-N'-methylformamidine. The expected complementary cleavage product 2, 4-dimethylformanilide was not produced in equivalent quantity. However, large amounts of polar metabolite(s) were produced. Small quantities of 2, 4-dimethylaniline and an unidentified non-polar metabolite were also produced. Of the identified chemicals only amitraz and N-2, 4-dimethylphenyl-N'-methylformamidine were toxic to larvae. Piperonyl butoxide applied simultaneously with amitraz had only a slight effect on metabolism but had a three-fold synergistic effect. SKF 525-A similarly applied had a negligible effect on both metabolism and toxicity.

Velocardiofacial (Shprintzen) syndrome: an important syndrome for the dysmorphologist to recognise.

We report the dysmorphological, genetic, and speech therapy aspects of 38 cases of velocardiofacial syndrome presenting to a craniofacial clinic and a specialised children's hospital, to indicate a relatively low incidence of clefting, good response to pharyngoplasty, considerable variability of the syndrome, and two further familial cases. We emphasise the low index of suspicion by paediatricians and paediatric subspecialists which resulted in delayed diagnosis and delayed treatment for the hypernasal speech and velopharyngeal insufficiency for periods of four months to seven years.