Oscillations of a falling spring

The motion of a spring, initially hanging in equilibrium from a fixed point with a mass attached to it, when it is detached from the fixed point, is considered.

Reduced height alleles (Rht) and Hagberg falling number of wheat

Near isogenic lines varying for alleles for reduced height (Rht) and photoperiod insensitivity (Ppd-D1) in cv. Mercia (2005/6 to 2010/11; rht (tall), Rht-B1b, Rht-D1b, Rht-B1c, Rht8c+Ppd-D1a, Rht-D1c, Rht12) and cvs Maris Huntsman and Maris Widgeon (2007/8 to 2010/11; rht (tall), Rht-B1b, Rht-D1b, Rht-B1c, Rht-B1b+Rht-D1b, Rht-D1b+Rht-B1c) were compared at one field site, but within different systems (‘organic’, O, 2005/6 to 2007/8 v ‘intensive’, I, 2005/6 to 2010/11). Further experiments at the site (2006/7 to 2008/9) compared 64 lines of a doubled haploid (DH) population [Savannah (Rht-D1b) × Renesansa (Rht-8c+Ppd-D1a)]. Gibberellin (GA) insensitive dwarfing alleles (Rht-B1b; Rht-B1c; Rht-D1b; Rht-D1c) could reduce α-amylase activity and/or increase Hagberg falling number (HFN) but effects depended greatly on system, background and season. Only Rht-B1c increased grain dormancy despite producing plants taller than Rht-D1c. The GA-sensitive Rht8c+Ppd-D1a in Mercia was associated with reduced HFN but analysis of the DH population suggested this was more closely linked with Ppd-D1a, rather than Rht8c. The severe GA-sensitive dwarfing allele Rht12 was associated with reduced HFN. Instability in HFN over season tended to increase with degree of dwarfing. There was a negative association between mean grain weight and HFN that was in addition to effects of Rht and Ppd-D1 allele.

Effects of absorbing aerosols in cloudy skies: a satellite study over the Atlantic Ocean

We present a method for deriving the radiative effects of absorbing aerosols in cloudy scenes from satellite retrievals only. We use data of 2005–2007 from various passive sensors aboard satellites of the “A-Train” constellation. The study area is restricted to the tropical- and subtropical Atlantic Ocean. To identify the dependence of the local planetary albedo in cloudy scenes on cloud liquid water path and aerosol optical depth (AOD), we perform a multiple linear regression. The OMI UV-Aerosolindex serves as an indicator for absorbing-aerosol presence. In our method, the aerosol influences the local planetary albedo through direct- (scattering and absorption) and indirect (Twomey) aerosol effects. We find an increase of the local planetary albedo (LPA) with increasing AOD of mostly scattering aerosol and a decrease of the LPA with increasing AOD of mostly absorbing aerosol. These results allow us to derive the direct aerosol effect of absorbing aerosols in cloudy scenes, with the effect of cloudy-scene aerosol absorption in the tropical- and subtropical Atlantic contributing (+21.2±11.1)×10−3 Wm−2 to the global top of the atmosphere radiative forcing.

It is always on your mind: experiences and perceptions of falling of older people and their carers and the potential of a mobile falls detection device

Background. Falls and fear of falling present a major risk to older people as both can affect their quality of life and independence. Mobile assistive technologies (AT) fall detection devices may maximise the potential for older people to live independently for as long as possible within their own homes by facilitating early detection of falls. Aims. To explore the experiences and perceptions of older people and their carers as to the potential of a mobile falls detection AT device. Methods. Nine focus groups with 47 participants including both older people with a range of health conditions and their carers. Interviews were audio recorded, transcribed verbatim, and thematically analysed. Results. Four key themes were identified relating to participants’ experiences and perceptions of falling and the potential impact of a mobile falls detector: cause of falling, falling as everyday vulnerability, the environmental context of falling, and regaining confidence and independence by having a mobile falls detector. Conclusion. The perceived benefits of a mobile falls detector may differ between older people and their carers. The experience of falling has to be taken into account when designing mobile assistive technology devices as these may influence perceptions of such devices and how older people utilise them.

Could in-home sensors surpass human observation of people with Parkinson’s at high risk of falling? An ethnographic study

Self-report underpins our understanding of falls among people with Parkinson’s (PwP) as they largely happen unwitnessed at home. In this qualitative study, we used an ethnographic approach to investigate which in-home sensors, in which locations, could gather useful data about fall risk. Over six weeks, we observed five independently mobile PwP at high risk of falling, at home. We made field notes about falls (prior events and concerns) and recorded movement with video, Kinect, and wearable sensors. The three women and two men (aged 71 to 79 years) having moderate or severe Parkinson’s were dependent on others and highly sedentary. We most commonly noted balance protection, loss, and restoration during chair transfers, walks across open spaces and through gaps, turns, steps up and down, and tasks in standing (all evident walking between chair and stairs, e.g.). Our unobtrusive sensors were acceptable to participants: they could detect instability during everyday activity at home and potentially guide intervention. Monitoring the route between chair and stairs is likely to give information without invading the privacy of people at high risk of falling, with very limited mobility, who spend most of the day in their sitting rooms.

(falling into) the space between the screen and the audience

The following is from a presentation at the Double Dialogues Conference, On Space, at The University of Otago, Dunedin, June 3, 2006.There is a space between things, and between things there is a space – a gap. This presentation considers the gap – that space in the cinema – between the audience and the screen. I am referring to the Cinema as an institution, and the cinema as a location. It is a space where films are screened: (often) with a screen, a projector facing the screen and an audience hovering between.

Older persons' perception of risk of falling : implications for fall-prevention campaigns

Objectives. We examined older people's attitudes about falls and implications for the design of fall-prevention awareness campaigns.

Methods. We assessed data from (1) computer-assisted telephone surveys conducted in 2002 with Australians 60 years and older in Northern Rivers, New South Wales (site of a previous fall-prevention program; n=1601), and Wide Bay, Queensland (comparison community; n=1601), and (2) 8 focus groups (n=73).

Results. Participants from the previous intervention site were less likely than were comparison participants to agree that falls are not preventable (odds ratio [OR]=0.76; 95% confidence interval [Cl]=0.65, 0.90) and more likely to rate the prevention of falls a high priority (OR=1.31; 95% CI=1.09, 1.57). There was no difference between the groups for self-perceived risk of falls; more than 60% rated their risk as low. Those with a low perceived risk were more likely to be men, younger, partnered, and privately insured, and to report better health and no history of falls. Focus group data indicated that older people preferred messages that emphasized health and independence rather than falls.

Conclusions. Although older people accepted traditional fall-prevention messages, most viewed them as not personally relevant. Messages that promote health and independence may be more effective.

Older people playing ball : what is the risk of falling and injury?

Increasing physical activity amongst seniors is important for public health, yet guidance is needed to minimise injury risks. To describe the incidence of falls/injuries in a walking team ball game (Lifeball) designed for seniors, a prospective cohort study was undertaken amongst community dwelling Lifeball participants in Australia. Players completed a telephone survey soon after commencing Lifeball (2004) and 12 months later (2005). Attendance and incident records were audited for the period. Subjects joined a Lifeball group with opportunity to play at least once per week. Baseline was completed by 284 players aged between 40 and 96 years (mean 67 years), with most (83.8%, 238/284) female. Of 263 followed up, the average attendances was 25, with 19.3% attending on fewer than 4 occasions and 14.3% attending 52 or more times. Most (93.9%) reported no injuries requiring medical attention. However, 16 (6.1%) had injuries requiring medical attention and their 27 injuries represent an injury rate of 3.3 per 1000 hours of participation. Twenty participants (7.6%) had a Lifeball fall equating to a fall rate of 2.8 per 1000 hours of participation. Falls in Lifeball were not associated with measured predictors (age, gender, falls history, perceived falls risk or hours played). Incident records showed a trip/stumble involving rushing, walking backwards, or overextending (all against rules) as common falling causes. Lifeball is not ‘risk free’ however due to a lack of comparative data it is difficult to compare injury rate to relevant activities. Prevention of injury should concentrate on enforcing safety rules.

The behaviour of infants/toddlers at 'falling-off' places

Toddlers were observed as they freely explored different 'falling-off' places on a visual cliff. Toddlers played extensively with wet / non-rigid surfaces (e.g. water) and briefly explored dry / rigid surfaces. Edges were crossed intentionally and unintentionally, either as an extension or consequence of edge engagement, by a sub-group of toddlers. The findings have implications for drowning / injury prevention.

Why the tuberculosis incidence rate is not falling in New Zealand

Aims To assess the role of migration from high-incidence countries, HIV/AIDS infection, and prevalence of multi-drug resistant organisms as contributors to tuberculosis (TB) incidence in New Zealand (NZ) relative to ongoing local transmission and reactivation of disease.

Methods TB notification data and laboratory data for the period 1995 to 2004 and population data from the 1996 and 2001 Census were used to calculate incidence rates of TB by age and ethnicity, country of birth (distinguishing high and low -incidence countries), and interval between migration and onset of disease. Published reports of multi-drug-resistant TB for the period 1995 to 2004 were reviewed. Anonymous HIV surveillance data held by AIDS Epidemiology Group were matched with coded and anonymised TB surveillance data to measure the extent of HIV/AIDS coinfection in notified TB cases.

Results Migration of people from high-TB incidence countries is the main source of TB in NZ. Of those who develop TB, a quarter does so within a year of migration, and a quarter of this group (mainly refugees) probably enter the country with pre-existing disease. Rates of local TB transmission and reactivation of old disease are declining steadily for NZ-born populations, except for NZ-born Māori and Pacific people under 40. HIV/AIDS and multi-drug-resistant organisms are not significant contributors to TB incidence in NZ and there is no indication that their role is increasing.

Conclusion TB incidence is not decreasing in NZ mainly due to migration of TB infected people from high-incidence countries and subsequent development of active disease in some of them in NZ. This finding emphasises the importance of regional and global TB control initiatives. Refugees and migrants are not acting as an important source of TB for most NZ-born populations. Those caring for them should have a high level of clinical suspicion for TB.