Shedding light on walking in the dark: the effects of reduced lighting on the gait of older adults with a higher-level gait disorder and controls

OBJECTIVE: To study the effects of reduced lighting on the gait of older adults with a high level gait disorder (HLGD) and to compare their response to that of healthy elderly controls. METHODS: 22 patients with a HLGD and 20 age-matched healthy controls were studied under usual lighting conditions (1000 lumens) and in near darkness (5 lumens). Gait speed and gait dynamics were measured under both conditions. Cognitive function, co-morbidities, depressive symptoms, and vision were also evaluated. RESULTS: Under usual lighting conditions, patients walked more slowly, with reduced swing times, and increased stride-to-stride variability, compared to controls. When walking under near darkness conditions, both groups slowed their gait. All other measures of gait were not affected by lighting in the controls. In contrast, patients further reduced their swing times and increased their stride-to-stride variability, both stride time variability and swing time variability. The unique response of the patients was not explained by vision, mental status, co-morbidities, or the values of walking under usual lighting conditions. CONCLUSION: Walking with reduced lighting does not affect the gait of healthy elderly subjects, except for a reduction in speed. On the other hand, the gait of older adults with a HLGD becomes more variable and unsteady when they walk in near darkness, despite adapting a slow and cautious gait. Further work is needed to identify the causes of the maladaptive response among patients with a HLGD and the potential connection between this behavior and the increased fall risk observed in these patients

Structural Investigations of Alkyl Mercury Sulphide, Alkyl Mercury Oxide and Alkyl Mercury Selenide by Dipole Moment Method

These structural investigations by the dipole moment m ethod follow earlier reported papers. On the basis of the influence of bond length, valence angles and electronegativity differences on the dipole moment, we expected to get some structural informations on these compounds

Structural Investigations of Alkyl Mercury Sulphide, Alkyl Mercury Oxide and Alkyl Mercury Selenide by Dipole Moment Method

These structural investigations by the dipole moment m ethod follow earlier reported papers. On the basis of the influence of bond length, valence angles and electronegativity differences on the dipole moment, we expected to get some structural informations on these compounds

Determination of the Bond Angle of Sulphur in Alkyl Mercuric Sulphides by Dipole Moment Method

The question of the bond angle in sulphur is still of interest, although large experimental evidence is available, obtained by different methods. However, these data are scarce in cases where sulphur is bound on electropositive atoms, as for example in alkyl mercuric sulphides. This paper gives a determinatio n of sulphur bond angle, based on experimental data obtained from dipole moment measurements of symmetrical and asymmetrical alkyl mercuric sulphides

A Beautiful Apocalypse: A Collection of Poems

My project consists of three poems on the subject of life in the year 2050. These poems explore and speculate the effects that air pollution, water contamination, deforestation, the government, and the economy will have on humans living in 2050

Territoriality, Prospecting, and Dispersal in Cooperatively Breeding Micronesian Kingfishers (\u3ci\u3eTodiramphus cinnamominus reichenbachii\u3c/i\u3e)

We investigated territoriality, prospecting, and dispersal behavior in cooperatively breeding Pohnpei Micronesian Kingfishers (Todiramphus cinnamominus reichenbachii) throughout the annual cycle using radiotelemetry and color-band resights. Mean home-range size was 6.3 ha and territories were 8.1 ha. Within territories, Micronesian Kingfishers shared 63% of their home-range space with coterritorial occupants, and 3% was shared with extraterritorial conspecifics. Birds on cooperative territories had larger home ranges that overlapped more with coterritory occupants’ home ranges than birds in pair-held territories. Despite evidence suggesting that resources necessary for survival and reproduction occurred on each territory, Micronesian Kingfishers of all age and sex classes made extraterritorial prospecting movements. Prospecting was rare; it comprised only 4.3% of our observations. When birds departed on forays, they were gone for ∼1.9 h and returned to home territories before sunset. Prospecting by dominant birds was temporally correlated with courtship and nest initiation, and birds were observed at neighboring nest sites with opposite-sex conspecifics during the period when females were available for fertilization. Juveniles and helpers prospected throughout the year and made repeated homesteading movements to dispersal destinations before dispersing. Mean dispersal distance for radiomarked individuals was 849 m. Results suggest that prospecting in Micronesian Kingfishers is a complex behavior that provides information for dispersal decisions and familiarity with dispersal destinations. Additionally, extraterritorial movements may provide covert opportunities for reproduction, which have potential to profoundly influence the distribution of fitness among helper and dominant Micronesian Kingfishers

Territoriality, Prospecting, and Dispersal in Cooperatively Breeding Micronesian Kingfishers (\u3ci\u3eTodiramphus cinnamominus reichenbachii\u3c/i\u3e)

We investigated territoriality, prospecting, and dispersal behavior in cooperatively breeding Pohnpei Micronesian Kingfishers (Todiramphus cinnamominus reichenbachii) throughout the annual cycle using radiotelemetry and color-band resights. Mean home-range size was 6.3 ha and territories were 8.1 ha. Within territories, Micronesian Kingfishers shared 63% of their home-range space with coterritorial occupants, and 3% was shared with extraterritorial conspecifics. Birds on cooperative territories had larger home ranges that overlapped more with coterritory occupants’ home ranges than birds in pair-held territories. Despite evidence suggesting that resources necessary for survival and reproduction occurred on each territory, Micronesian Kingfishers of all age and sex classes made extraterritorial prospecting movements. Prospecting was rare; it comprised only 4.3% of our observations. When birds departed on forays, they were gone for ∼1.9 h and returned to home territories before sunset. Prospecting by dominant birds was temporally correlated with courtship and nest initiation, and birds were observed at neighboring nest sites with opposite-sex conspecifics during the period when females were available for fertilization. Juveniles and helpers prospected throughout the year and made repeated homesteading movements to dispersal destinations before dispersing. Mean dispersal distance for radiomarked individuals was 849 m. Results suggest that prospecting in Micronesian Kingfishers is a complex behavior that provides information for dispersal decisions and familiarity with dispersal destinations. Additionally, extraterritorial movements may provide covert opportunities for reproduction, which have potential to profoundly influence the distribution of fitness among helper and dominant Micronesian Kingfishers

On the Mercury Phosphoiodide Hg3P2I2

M. Granger decribed the preparation and the properties of mercury phosphide Hg3P4. The present authors repeated Granger\u27s experiments and obtrained a crystallized compound showing the same properties but with a composition given by the formula: Hg3P2l2. No compound which contained only phosphorus and mercury could be obtained by the method described

On the Mercury Phosphoiodide Hg3P2I2

M. Granger decribed the preparation and the properties of mercury phosphide Hg3P4. The present authors repeated Granger\u27s experiments and obtrained a crystallized compound showing the same properties but with a composition given by the formula: Hg3P2l2. No compound which contained only phosphorus and mercury could be obtained by the method described