Impact of Individual and Combined Sensory Impairment in Older Australians

Purpose: To estimate the prevalence and examine the clustering patterns of visual, auditory and olfactory impairments; to estimate the associations of olfactory impairment with neurodegenerative and other morbidities; to estimate the associations of visual and auditory impairments with morbidity and mortality using Cox regression; and to examine the associations of visual and auditory impairments with morbidity and mortality using structural equation modelling to identify potential indirect pathways and assess whether Cox regression underestimated the associations between VI, AI and mortality in a representative sample of older Australians. Methods: The Blue Mountains Eye Study (BMES) examined 3,654 persons aged 49+ during 1992-1994, and after 5 and 10 years. The Blue Mountains Hearing Study (BMHS) invited participants who attended the second cross-sectional survey of the Blue Mountains Eye Study (BMES 2). Persons who moved into the study area or study age group, identified from a repeat door-to door census in 1999, were also invited to participate. The Blue Mountains Hearing Study (BMHS) examined 2956 persons aged 49+ years (75.5% response) during 1997-2000. Vision, hearing and olfaction were assessed in BMES 3. Assessment was by interviewer administered structured questionnaire, clinical examination, audiometry, blood testing and the San Diego Odor Identification Test. A total of 1,497 (74.3% of all participants) had complete vision, auditory and olfactory data after BMES 3. Visual impairment (VI) was categorized as either: presenting visual impairment (PVI), VA less than 6/12 Snellen equivalent (25 decibels hearing level (dBHL). Cognitive impairment was defined as mini mental state exam (MMSE) scores <24. Log-linear models were used to assess the concomitant presence of the three sensory impairments (visual, auditory and olfactory). Observed frequencies of concomitant sensory impairments were compared to the expected frequencies estimated assuming they occurred independently (no clustering tendency). Multivariable adjusted logistic regression models were constructed to estimate associations between olfactory impairment and morbidities, including neurodegenerative conditions. Associations between visual impairment and mortality risk, and between hearing loss and mortality risk, were estimated using Cox regression and structural equation modelling (SEM). Odds ratios (OR), hazard ratios (HR) and 95% confidence intervals (CI) are presented. A p-value of less than 0.05 was considered statistically significant. Australian National Death Index data confirmed deaths until 2005.   Results: After13 years from baseline, 1273 participants had died. After 5 years from BMES 2 (BMHS), 403 participants had died. At BMES 3, the prevalence of PVI, CVI and NCVI was 11%, 8% and 3% respectively. The prevalence of any OI was 27.0% and the prevalence of AI was 43%. The observed prevalence of having all three sensory impairments in persons with PVI (or NCVI) was 2.6 (or 3.0) times greater than predicted if they clustered independently. VI, AI and OI clustered differently in women compared to men. Inverse associations were observed between OI and body mass index (OR per 5 kg/m2 increase, 0.8, CI 0.7-0.9) and between moderate impairment and hypertension (OR 0.6, CI 0.4-0.9). There was no significant relationship with angina, previous myocardial infarction or diabetes. Persons with Parkinson disease had an increased likelihood of both mild (OR 9.8, CI 2.0-47.5) and moderate OI (OR 16.1, CI 3.8-68.2), as did persons with impaired cognitive function (OR 3.3, CI 1.3-8.6 and OR 3.7, CI 1.5-9.6, respectively). After adjusting for mortality risk markers using Cox regression, higher mortality was associated with NCVI (HR 1.35, CI 1.04-1.75). This association was stronger for ages <75 years (HR 2.58, CI 1.42-4.69). Structural equation modelling revealed greater effects of NCVI on mortality risk (HR 5.25, CI 1.97-14.01 for baseline ages <75), with both direct (HR 2.16, CI 1.11-4.23) and indirect effects (HR 2.43, CI 1.17-5.03). Of the mortality risk markers examined, only disability in walking demonstrated a significant indirect pathway for the link between VI and mortality. Disability in walking acted both directly on mortality and via an association with self-rated health. Using Cox regression, hearing loss was associated with increased risk of both cardiovascular (HR 1.36, CI 1.08-1.84) and all-cause mortality (HR 1.39, CI 1.11-1.79) after adjustment for age and sex, but not after multivariable adjustment. Structural equation modelling pathway analysis, however, revealed a higher all-cause mortality risk (HR 2.58, CI 1.64-4.05) in persons with hearing loss, which was mediated by two variables: cognitive impairment (HR 1.45, CI 1.08-1.94) and disability in walking (HR 1.63, CI 1.24-2.15). These variables increased mortality both directly and indirectly through effects on self-rated health. Conclusions: In this representative population of older Australians, over one in ten persons had VI, over one in four persons had OI and almost one in two persons had AI. The prevalence of VI, AI and OI increased with increasing age. The prevalence of AI and OI was higher in males. The prevalence of VI was higher in females. Visual, auditory and olfactory impairments aggregated mutually and dependently. Visual impairment and AI were significantly associated with morbidity and mortality. Visual impairment predicted mortality by both direct and indirect pathways. Auditory impairment predicted mortality via indirect pathways. Disability in walking, which can substantially influence general health, represented a major indirect pathway for both VI and AI. Auditory impairment was also associated with increased all-cause mortality via cognitive impairment and self-rated health. Adjustment for these co-variables using Cox regression underestimated the associations between VI and AI and mortality. Olfactory impairment was inversely associated with BMI and hypertension. Olfactory impairment was significantly higher among persons with Parkinson disease and cognitive impairment. It is important to recognise that persons with sensory impairments are at increased risk of important comorbidities and mortality. Dependent clustering of sensory impairments suggest the possibility of a common underlying mechanism and that separate hearing and vision services may not adequately support older persons

Traduire, une lecture en profondeur

L’insoutenable légèreté de la lecture. Nicholas Carr, dans son dernier livre The Shallows : What the Internet is Doing to Our Brains, étudie la façon dont l’internet modifie nos capacités cognitives et remodèle littéralement nos cerveaux malléables. D’autres – tel Malcolm Jones, journaliste à Newsweek, dans un article de juin 2010 Slow Reading : An Antidote for a Fast World ?– considèrent que nous lisons trop et trop vite. Mais N. Carr, s’appuyant largement sur la neurophysiologie et l’histoi..

Frequency matching in light storage spectroscopy of atomic Raman transitions

We investigate the storage of light in an atomic sample with a lambda-type coupling scheme driven by optical fields at variable two-photon detuning. In the presence of electromagnetically induced transparency (EIT), light is stored and retrieved from the sample by dynamically varying the group velocity. It is found that for any two-photon detuning of the input light pulse within the EIT transparency window, the carrier frequency of the retrieved light pulse matches the two-photon resonance frequency with the atomic ground state transition and the control field. This effect which is not based on spectral filtering is investigated both theoretically and experimentally. It can be used for high-speed precision measurements of the two-photon resonance as employed e.g. in optical magnetometry.Comment: 10 pages, 4 figures; minor amendments implemented

Preventing and Reversing Vacuum-Induced Optical Losses in High-Finesse Tantalum (V) Oxide Mirror Coatings

We study the vacuum-induced degradation of high-finesse optical cavities with mirror coatings composed of SiO$_2$-Ta$_{2}$O$_{5}$ dielectric stacks, and present methods to protect these coatings and to recover their initial quality factor. For separate coatings with reflectivities centered at 370 nm and 422 nm, a vacuum-induced continuous increase in optical loss occurs if the surface-layer coating is made of Ta$_{2}$O$_{5}$, while it does not occur if it is made of SiO$_2$. The incurred optical loss can be reversed by filling the vacuum chamber with oxygen at atmospheric pressure, and the recovery rate can be strongly accelerated by continuous laser illumination at 422 nm. Both the degradation and the recovery processes depend strongly on temperature. We find that a 1 nm-thick layer of SiO$_2$ passivating the Ta$_{2}$O$_{5}$ surface layer is sufficient to reduce the degradation rate by more than a factor of 10, strongly supporting surface oxygen depletion as the primary degradation mechanism.Comment: 14 pages, 7 figure

Artificial Intelligence, Surveillance, and Big Data

The most important resource to improve technologies in the field of artificial intelligence is data. Two types of policies are crucial in this respect: privacy and data-sharing regulations, and the use of surveillance technologies for policing. Both types of policies vary substantially across countries and political regimes. In this paper, we examine how authoritarian and democratic political institutions can influence the quality of research in artificial intelligence, and the availability of large-scale datasets to improve and train deep learning algorithms. We focus mainly on the Chinese case, and find that – ceteris paribus – authoritarian political institutions continue to have a negative effect on innovation. They can, however, have a positive effect on research in deep learning, via the availability of large-scale datasets that have been obtained through government surveillance. We propose a research agenda to study which of the two effects might dominate in a race for leadership in artificial intelligence between countries with different political institutions, such as the United States and China.210

Incidence, persistence, and progression of tinnitus symptoms in older adults : the Blue Mountains hearing study

Objective: Temporal population-based data on tinnitus are lacking. We used a representative older population-based cohort to establish 5-yr incidence, persistence, and progression of tinnitus symptoms. Design: Two thousand six participants of the Blue Mountains Hearing Study (1997-1999) had complete tinnitus data, and of these, 1214 participants were followed up at 5-yr examinations in 2002-2004. Presence of prolonged tinnitus was assessed by a positive response to a single question administered by an audiologist. Incident tinnitus was defined in participants who were free of tinnitus symptoms at the baseline study in 1997-1999 but who reported tinnitus symptoms at the 5-yr follow-up in 2002-2004. Progression of tinnitus was defined as the increase in annoyance of tinnitus symptoms from baseline to the 5-yr follow-up study. Persistence of tinnitus symptoms was defined as the presence of tinnitus symptoms at both the baseline and follow-up examinations. Hearing impairment was measured as the pure-tone average (PTA) of audiometric hearing thresholds at 500, 1000, 2000, and 4000 Hz (PTA0.5-4 kHz), defining bilateral hearing loss as PTA0.5-4 kHz >25 dB HL. Results: Five-year incidence of tinnitus was 18.0%. A significant age trend was observed for the 5-yr incidence (p = 0.005), with incident tinnitus decreasing with age. Hearing loss increased the risk of developing incident tinnitus, age-sex adjusted odds ratio 2.13 (95% confidence interval, 1.40 to 3.24). Most (55.5%) incident tinnitus cases reported symptoms that were only mildly annoying. Tinnitus at baseline persisted in 81.6% of participants. Of those reporting mildly annoying tinnitus at baseline, 39.6% progressed to moderately annoying and 5.9% to severely annoying tinnitus. At the follow-up, a higher frequency of participants with persistent tinnitus (old cases) reported their symptoms as very/extremely annoying compared with the new (incident) cases of tinnitus (p = 0.01). A high proportion (85.2%) of subjects receiving tinnitus treatment (mainly medications and hearing aid) at baseline still reported tinnitus at 5-yr examinations. Conclusions: Incident tinnitus was frequent, with nearly one in five older adults suffering from this condition after 5 yrs. Tinnitus symptoms persisted in more than three-quarters of the cohort, during the 5 yrs. Longitudinal data are an important contribution to the research evidence base to support timely intervention and effective management of this frequent symptom.6 page(s

Risk factors and impacts of incident tinnitus in older adults

Purpose: We used a representative older population-based cohort to establish the predictors and impacts of tinnitus. Methods: A total of 1,214 participants of the Blue Mountains Hearing Study were followed for 5 years (1997 − 1999 to 2002 − 2004). The presence of tinnitus was assessed by an audiologist-administered questionnaire. Hearing impairment was defined as the pure tone average (PTA)0.5–4KHz > 25 dB HL, in the better ear. Quality of life was measured by use of the Short Form 36-item Health Survey (SF-36). Depression was assessed using either the SF-36 (Mental Health Index, subscale) and the Center for Epidemiologic Studies Depression Scale. Results: Symptomatic dizziness and hearing loss were significant risk factors for incident tinnitus, multivariable-adjusted odds ratio, 2.41 (95% confidence interval, 1.62–3.58) and odds ratio 2.31 (95% confidence interval, 1.46–3.66), respectively. Incident tinnitus cases demonstrated significantly lower mean SF-36 scores compared with subjects without tinnitus and were more likely to be depressed as assessed by both the Mental Health Index and Center for Epidemiologic Studies Depression Scale. Conclusions: Incident tinnitus was predicted by two otological risk factors, dizziness and hearing loss. Temporal data documented diminished quality of life and psychological well-being in those subjects experiencing tinnitus. This finding highlights the importance of effective intervention strategies to prevent potentially debilitating morbidity associated with tinnitus.7 page(s

Direct and indirect effects of visual impairment on mortality risk in older persons : the Blue Mountains eye study

Objective: To investigate pathways from visual impairment to increased all-cause mortality in older persons. Methods: The Blue Mountains Eye Study examined 3654 persons 49 years and older (82.4% response) during 1992-1994 and after 5 and 10 years. Australian National Death Index data confirmed deaths until 2005. Visual impairment was defined as presenting, correctable, and noncorrectable, using better-eye visual acuity. Associations between visual impairment and mortality risk were estimated using Cox regression and structural equation modeling. Results: After 13 years, 1273 participants had died. Adjusting for mortality risk markers, higher mortality was associated with noncorrectable visual impairment (hazardratio [HR], 1.35; 95% confidence interval [CI], 1.04-1.75). This association was stronger for ages younger than 75 years (HR, 2.58; 95% CI, 1.42-4.69). Structural equation modeling revealed greater effects of noncorrectable visual impairment on mortality risk (HR, 5.25; 95% CI, 1.97-14.01 for baseline ages _75 years), with both direct (HR, 2.16; 95% CI, 1.11-4.23) and indirect (HR, 2.43; 95% CI, 1.17-5.03) effects. Of mortality risk markers examined, only disability in walking demonstrated a significant indirect pathway for the link between visual impairment and mortality. Conclusions: Visual impairment predicted mortality by both direct and indirect pathways, particularly for persons younger than 75 years with noncorrectable visual impairment. Disability in walking, which can substantially influence general health, represented a major indirect pathway.7 page(s

Associations between hearing impairment and mortality risk in older persons : the Blue Mountains hearing study

Purpose: To assess whether hearing loss predicts an increased risk of mortality. Methods: The Blue Mountains Hearing Study examined 2956 persons (49+ years) during 1997 to 2000. The Australian National Death Index was used to identify deaths until 2005. Hearing loss was defined as the pure-tone average (0.5−4 kHz) of air-conduction hearing thresholds greater than 25 dB HL. Associations between hearing loss and mortality risk were estimated using Cox regression and structural equation modeling (SEM). Results: When we used Cox regression, we discovered that hearing loss was associated with increased risk of cardiovascular (hazard ratio [HR] 1.36, 95% confidence interval [CI] 1.08−1.84) and all-cause (AC) mortality (HR 1.39, 95% CI 1.11−1.79) after adjustment for age and sex but not after multivariable adjustment. SEM pathway analysis, however, revealed a greater AC mortality risk (HR 2.58, 95% CI 1.64−4.05) in persons with hearing loss, which was mediated: cognitive impairment (HR 1.45, 95% CI 1.08−1.94) and walking disability (HR 1.63, 95% CI 1.24−2.15). These variables increased mortality both directly and indirectly through effects on self-rated health. Conclusions: Hearing loss was associated with increased AC mortality via three mediating variables: disability in walking, cognitive impairment, and self-rated health. It is important to recognize that persons with combined disabilities are at increased risk of cardiovascular and AC mortality.8 page(s