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This study aimed to better understand the extent to which older adult centres are a focal point for recreation and social activities for their members. Travel diaries completed by 261 members of 12 older adult centres across Ontario provided comprehensive and real-time (24-hour) data over two consecutive weeks concerning time away from home, trip purposes, and modes of travel. The data showed that nearly one-third of their trips included a stop at their older adult centre. Three-quarters also went to other community venues over the study period, possibly to access amenities (e.g., pools) not available at their centre. Notwithstanding, their local older adult centre was still a focal point in out-of-home travel, particularly for potentially more vulnerable older adults, including those who were non-drivers, had less education, and felt lonelier. The diaries also substantiated the importance of time spent socializing with peers and staff at the centre, apart from formal program participation.
Vultures are long-lived species sensitive to human-caused mortality that has already determined a widespread collapse in Asian and African populations. They provide significant ecosystem services (regulatory and cultural) consuming livestock carcasses and saving greenhouse gas emissions, favouring nutrient recycling, environmental sanitation, and providing financial revenue. Appraising the incidence and causes of mortality could help to improve management and conservation actions. We compiled records of reported mortalities for the reintroduced Griffon Vulture Gyps fulvus population of the central Apennines in Italy (123 cases, July 1994–December 2020). The average mortality was 4.69 vultures per year (± 1.14 SE), with no significant temporal trend. The peak of mortality events, estimated by harmonic regression analysis, was in March, while the minimum occurred in October. No differences were found among age classes and sex ratio mortality was established at 1.43:1 (M:F, N = 68). Out of 103 (83.7%) vultures which underwent a post-mortem and toxicological screening, 53% were poisoned, mainly by carbamates, and 27% died of unknown causes. Overall, direct or indirect anthropogenic mortality caused 67% of deaths. Even considering an inherent bias associated with reported mortality as to the prevalence of causes of death and estimation of mortality rates, the overwhelming relevance of poisoning highlights that existing anti-poisoning efforts should be refined and incorporated into a coordinated multidisciplinary strategy. A standardised approach, from vulture carcass discovery to post-mortem procedures and toxicological analysis, should be applied to reduce uncertainty in the determination of causes of death, increasing effectiveness in the prosecution of wildlife crimes. As most of the poisoning cases affecting the Griffon Vulture population in the central Apennines likely represent a side (though illegal) effect of retaliatory efforts to defeat livestock predators, effective strategies in reducing human–wildlife conflicts should be applied.
Direct numerical simulations of turbulent channel flow subjected to spanwise wall oscillations in the form of streamwise travelling waves (STW) were performed in an effort to elucidate the mechanism responsible for the observed drag reduction. We imposed large amplitudes to identify the proper effects of STW, while keeping the angular frequency and wavenumber fixed at a particular values. We primarily focus on the vorticity transport mechanism, to better understand the influence of STW actuation on the near-wall turbulence. We identify key terms appearing in the turbulent enstrophy transport equations that are directly linked to the STW actuation. The analysis reveals that the primary effect of the STW forcing is to attenuate the spanwise turbulent enstrophy at the wall, which is linked to the fluctuating wall shear stress. The suppression of the wall-normal turbulent enstrophy is deemed to be subordinate. To strengthen this point, we performed numerical experiments, where the streamwise fluctuating velocity, and consequently the spanwise vorticity, is artificially suppressed next to the wall. The anisotropic invariant maps show striking resemblance for large amplitude STW actuation and artificially forced cases. Detailed analysis of various structural features is provided, which includes the response of the near-wall streaks and shear layers of spanwise fluctuating velocity field. The quasistreamwise vortices, which play a key role in the regeneration mechanism, are shown to be pushed away from the wall, resulting in their weakened signature at the wall.
An exact analytical solution is obtained for the dynamical system derived in Part 1 of this series (Moffatt & Kimura, J. Fluid Mech, vol. 861, 2019a, pp. 930–967), which describes the approach of two initially circular vortices of finite but small cross-section symmetrically located on inclined planes. This exact solution, applicable in the inviscid limit, allows determination of the amplification $\mathcal {A}_{\omega }$ of the axial vorticity within the finite time $T$ during which the basic assumptions of the model continue to apply. It is first shown that, for arbitrarily prescribed $\mathcal {A}_{\omega }$, it is possible to specify smooth initial conditions of finite energy such that, in the inviscid limit, this amplification is achieved within the time $T$. When viscosity is included, an estimate is provided for the minimum vortex Reynolds number that is sufficient for the same result to hold. The predictions are broadly compatible with results from direct numerical simulations at moderate Reynolds numbers. Moreover, it is shown that one may come arbitrarily close to a finite-time singularity of the Navier–Stokes equation by appropriate choice of an initial, smooth, finite-energy velocity field; however, this approach to a singularity is ultimately thwarted through breach of the assumptions on which the dynamical system is based. Thus we make no claim here concerning realisation of a Navier–Stokes singularity. Moreover, we find that the conditions required to attain a large amplification $\mathcal {A}_{\omega }\gg 1$ during the time $T$ are far beyond those that can be realised in either experiment or direct numerical simulation.
The issue of self-neglect among older adults is receiving attention in modern societies where aging is accelerating. To help expand our understanding of this phenomenon, this study identified its different types using latent profile analysis and verified the main variables that distinguish these types from each other. The three profiles that were identified are high self-neglect (HSN: 28.8%), low self-neglect (LSN: 35.6%), and poor personal hygiene (PPH: 35.6%). Interestingly, PPH showed a high rate and was identified as a noticeable type of elder self-neglect. Gender, age group, SES, support size, and suicidal ideation were significant in classifying the types of self-neglect. Men were more likely to be within the HSN group, and late elderly were more likely to be within the PPH group. The higher SES and social support, the higher the probability of being within the LSN group. The higher the suicidal ideation, the higher the possibility of falling under the HSN group. To reduce self-neglect among older adults, this study suggests to older adults vulnerable to self-neglect, expansion of the social support available to them, and provision of mental health services to this population.
This paper deals with the phenomenon of poverty-trap regimes in Mexico, that is, self-reinforcing mechanisms in which municipalities which start poor remain poor. We develop a coordination game of poverty traps driven by strategic interactions of economic agents: people choose to complete or not their education levels since it might be excessively costly and unprofitable. A one-shot game is constructed and then converted into a system of differential equations in which strategies that perform relatively better become more abundant in the population. Applying evolutionary games and symbolic-regimes dynamics (nonparametric and nonlinear techniques), we show that Mexican regions are in poverty-trap regimes (stable and dynamically evolving low-level equilibria) characterized by incomplete education and low income since initial conditions (education and income per capita) are such (very precarious) that poverty is the stable steady-state situation. We examine scenarios to show that to overcome the high-poverty regime by the year 2030, it is necessary to reduce incomplete education by 10% in the 5-year periods 2020–2025 and 2025–2030 and increase per-capita income by 10% in both periods.