Older Age Structure Research Articles

COVID-19 in Hong Kong: Policies and community actions mitigate the effects of age structure and population density

Despite the various socio-demographic vulnerabilities of Hong Kong to the COVID-19 pandemic, the city has successfully managed four waves of local outbreaks, as shown by its comparatively low numbers of confirmed cases and deaths. In this paper, we identify and differentiate the unique characteristics of Hong Kong’s COVID-19 outbreaks from those of other territories, and analyse the factors that shaped these characteristics. In particular, we examine four local demographic factors – older age structure, high population density, poor housing conditions and a large migrant population – which, according to current scientific evidence, would likely indicate that the city faces a relatively high risk of the significant spread of COVID-19. We analyse and explain how multiple policies related to border controls, social distancing, testing and tracing, partial lockdowns and housing management, as well as sustained community actions, helped to mitigate the effects of these significant disadvantages.

The demise of the rural Nordic region? Analysisof regional population trends in the Nordic countries, 1990 to 2040

The population of the Nordic region has grown substantially during recent decades, though most of this growth has been in urban regions. While the Nordic countries are projected to see continued population growth in the future, almost all of the increase will be concentrated in urban centres, with population decline or stagnation in many rural municipalities. This will make it difficult for these regions to remain economically competitive and for national governments to provide a uniform level of services across entire countries. This article provides policymakers at the national, regional, and municipal levels with projections of the size, composition, and geographic distribution of rural populations in the Nordic countries in 2040. In total, remote rural regions will not become depopulated and are projected to grow moderately from 5.3 to 5.5 million persons to 2040, though many will experience significant declines in their total and working-age populations and will have much older age structures. For many rural municipalities in the Nordic region, their population peak was at some point in the distant past, and they should therefore develop policies based on smaller populations.

Ageing badly: indicators of old-age structure in Australia and New Zealand.

INTRODUCTION Until 2050, Australia and New Zealand will experience continuing increase in the population aged >65 years. Studying differences in indicators of old-age structure between these countries can inform policymakers. AIM To calculate and analyse indicators of old-age structure for Australia and New Zealand. METHODS Five indicators of old-age structure were calculated: centenarian ratio (number of centenarians per 100,000 people), longevity index (proportion of people aged ≥90 and ≥65 years in the population), longevity level (proportion of 80+/60+ years population), ageing tendency (proportion of people aged ≥60 years in the population) and centenarity index (ratio between the centenarians and the total population ≥90 years). RESULTS All indicators of old-age structure demonstrated an advantageous ageing structure in Australia compared with New Zealand. In addition, the New Zealand Māori and Australian Aboriginal indicators of old-age structure demonstrated a significant disadvantage to these ethnic groups compared with the general population. DISCUSSION Public health policy needs to target ageing in New Zealand as a major goal in advancing the 'Ageing Well' policy advocated by the government.

Fertility, migration, and the ageing of the population--an analysis of the official projections.

"As we move through the demographic transition, an older age structure is inevitable but future possible scenarios vary.... The paper analyses nine different population projections produced by the ABS [Australian Bureau of Statistics], four in 1996 and five in 1998. The highest projection...adds an extra ten million people by the year 2051 while the lowest...adds none."

The Czech Pirate Party in the 2010 and 2013 Parliamentary Elections and the 2014 European Parliament Elections: Spatial Analysis of Voter Support

Abstract The paper presents a spatial analysis of the Czech Pirate Party (Pirates) voter support in the 2010 and 2013 parliamentary elections and the 2014 European Parliament elections. The main method applied for classifying electoral results was the spatial autocorrelation and spatial regression. The result of the analysis has shown that territorial support for the Pirates copies to a great extent the areas of high support for right-wing parties and simultaneously the areas exemplified by a high development potential. In the case of spatial characteristics, little support for the Pirates was shown in Moravia and higher in the Sudetenland in terms of determinants of support. Additionally to spatial regimes, inter-regional support for the Pirates was also influenced by other non-spatial characteristics, although the strength of their influence was relatively weak. The units which embodied a successful environment for voting for the Pirates were particularly characterized by greater urbanization and a greater number of entrepreneurs, while a lack of jobs and the older age structure, i.e. the signs that in the socio-economic, or socio-ecological sense define peripheral areas, negatively impacted the gains of the Pirates. Ambiguous influence was exercised by college-educated inhabitants, who in the parliamentary elections in 2010 and 2013 decreased the gains of the Pirates, however, in the elections to the European Parliament in 2014 a direction of relationship was modified and turned positive.

Evaluation of harvest indices for monitoring cougar survival and abundance

ABSTRACTHarvest indices are used by state wildlife management agencies to monitor population trends and set harvest quotas for furbearer species. Although harvest indices may be readily collected from hunters, the reliability of harvest indices for monitoring demography and abundance of the harvested species is rarely examined, particularly amongst large carnivores. The overall objective of this study was to assess whether cougar (Puma concolor) harvest statistics collected by wildlife managers were correlated with changes in cougar demography, mainly survival rates and abundance. We estimated key demographic parameters for 2 cougar populations in Utah over 17 years during which we monitored 235 radio‐collared cougars. We then compared these demographic parameters to harvest statistics provided by the Utah Division of Wildlife Resources over the same time period for the Oquirrh‐Stansbury (lightly harvested population) and Monroe (heavily harvested population) harvest management units. In the Oquirrh‐Stansbury unit, the percent of harvested cougars >6 years old was positively correlated with annual survival, indicative of a population experiencing several years of high survival resulting in an older age structure. Percent of permits filled and cougar abundance were also significantly correlated, suggesting higher hunting success with increased density. In the Monroe management unit, the annual percent of permits filled was correlated with changes in overall annual survival and male and female annual survival. Of utmost importance, pursuit success (cougars treed/day) increased with the number of cougars on the unit suggesting that pursuit indices may be an informative metric for wildlife managers to determine cougar population trends. Because both management units were subjected to contrasting mortality regimes, results provided by this assessment could potentially be applied to additional management areas sharing similar ecological characteristics and harvest metrics. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Experimental and analytical behavior of strengthened reinforced concrete columns with steel angles and strips

The need of strengthening reinforced concrete columns, due to loss of strength and/or stiffness, is an essential requirement due to variation of the loads and environmental conditions applied on these columns. Steel jackets around the reinforced concrete (RC) columns are usually made by means of steel plates covering all over the column surface area. For the value of engineering purposes, another technique was developed using steel angles at the corners of the RC columns connected with discrete steel strips. In this paper, an experimental program is designed to evaluate the improvement in load-carrying capacity, stiffness and ductility of strengthened RC columns, concomitant with steel angles and strips. Despite of prevailing a substantially increased loading capacity and strength a pronounced enhancement in ductility and stiffness has been reported. A need for experimental test results with low value of concrete strength to mimic the local old-age structures condition that required strengthening in local countries. Seven columns specimens are tested to evaluate the strength improvement provided by steel strengthening of columns. The method of strengthened steel angles with strips is compared with another strengthening technique. This technique includes connected and unconnected steel-casing specimens. The observed experimental results describe load-shortening curves, horizontal strains in stirrups and steel strips, as well as description of failure mode. The extra-confinement pressure, due to existence of steel cage, of the strengthened RC column can be also observed from experimental results. The code provisions that predict the load-carrying capacity of the strengthened RC composite column has a discrepancy in the results. For this reason, an analytical model is developed in this paper to compare the code limit with experimental observed results. The proposed model accounts for the composite action for concrete confinement and enhancement of the local buckling of steel elements. This adopted model is simplified and applicable to practical design field. In this respect, the experimental results and those of the analytical model showed a good agreement.

Local-Area Age Structure and Population Composition

This study examines relationships between local-area age structure and health at older ages. We estimate random intercept models for two disability measures using four waves of data from a national panel study of 3,580 Japanese older adults. Elderly living in relatively older areas reported more difficulties with activities of daily living compared with those living in an "average" age structure. Controlling for individual characteristics and time did little to change this relationship; while a similar relationship between older age structure and functional limitations emerged. Residents of relatively older areas tended to have lower socioeconomic status, but this "disadvantage" was offset by their higher rates of employment and marriage. These compositional differences highlight the role of local-area age structure in identifying and understanding elderly health variation between places.

Precision of two methods for estimating age from burbot otoliths

Lower reproductive success and older age structure are associated with many burbot (Lota lota L.) populations that are declining or of conservation concern. Therefore, reliable methods for estimating the age of burbot are critical for effective assessment and management. In Lake Erie, burbot populations have declined in recent years due to the combined effects of an aging population ( = 10 years in 2007) and extremely low recruitment since 2002. We examined otoliths from burbot (N = 91) collected in Lake Erie in 2007 and compared the estimates of burbot age by two agers, each using two established methods (cracked-and-burned and thin-section) of estimating ages from burbot otoliths. One ager was experienced at estimating age from otoliths, the other was a novice. Agreement (precision) between the two agers was higher for the thin-section method, particularly at ages 6–11 years, based on linear regression analyses and 95% confidence intervals. As expected, precision between the two methods was higher for the more experienced ager. Both agers reported that the thin sections offered clearer views of the annuli, particularly near the margins on otoliths from burbot ages ≥8. Slides for the thin sections required some costly equipment and more than 2 days to prepare. In contrast, preparing the cracked-and-burned samples was comparatively inexpensive and quick. We suggest use of the thin-section method for estimating the age structure of older burbot populations.

Sexual mixing patterns among social networks of HIV-positive and HIV-negative Beijing men who have sex with men: a multilevel comparison using roundtable network mapping

Men who have sex with men (MSM) are of immediate concern in China's HIV epidemic. In 2008, approximately 2.5–6.5% of China's eight million MSM were HIV positive, while MSM represented 11% of all new HIV cases. Two factors that will in-part determine HIV-transmission dynamics among MSM, are sexual mixing patterns and the social networks which shape them. Sexual mixing patterns and social networks of Chinese MSM, however, remain poorly understood with little refined data available. One reason is that stigma discourages disclosure of names and identifiers to researchers. Using an alternative network-mapping approach, matched case–control design, and snowball sampling, this pilot study sought to compare characteristics of social networks of HIV-positive and HIV-negative Beijing MSM at the individual, dyad, and network levels. First, HIV-negative MSM controls were matched to HIV-positive MSM cases based on age, education, residency, and ethnicity. Then, each case or control and their MSM social network convened at a specific time and location with study investigators. Venues included health clinics, karaoke clubs, brothels, and community centers. Then, using arbitrarily assigned numbers in lieu of actual names, all participants simultaneously completed self-administered surveys regarding their sexual relationships with other participants of the same social network. These new findings indicate that cross-generational sex (anal or oral sex between men with ≥10 years age difference) was more prevalent among social networks of HIV-positive MSM, and was due to older age structure of the social network, rather than behavioral differences in sex-partner selection. Members of social networks of HIV-positive MSM were also less likely to have ever disclosed their MSM identity to non-MSM. Future studies should partner with MSM advocacy groups to explore behavioral and structural interventions as possible means of reducing the cross-generational sex and sexual identity-development issues elevating HIV risk for young Chinese MSM.

Probable causes of increasing brucellosis in free‐ranging elk of the Greater Yellowstone Ecosystem

While many wildlife species are threatened, some populations have recovered from previous overexploitation, and data linking these population increases with disease dynamics are limited. We present data suggesting that free-ranging elk (Cervus elaphus) are a maintenance host for Brucella abortus in new areas of the Greater Yellowstone Ecosystem (GYE). Brucellosis seroprevalence in free-ranging elk increased from 0-7% in 1991-1992 to 8-20% in 2006-2007 in four of six herd units around the GYE. These levels of brucellosis are comparable to some herd units where elk are artificially aggregated on supplemental feeding grounds. There are several possible mechanisms for this increase that we evaluated using statistical and population modeling approaches. Simulations of an age-structured population model suggest that the observed levels of seroprevalence are unlikely to be sustained by dispersal from supplemental feeding areas with relatively high seroprevalence or an older age structure. Increases in brucellosis seroprevalence and the total elk population size in areas with feeding grounds have not been statistically detectable. Meanwhile, the rate of seroprevalence increase outside the feeding grounds was related to the population size and density of each herd unit. Therefore, the data suggest that enhanced elk-to-elk transmission in free-ranging populations may be occurring due to larger winter elk aggregations. Elk populations inside and outside of the GYE that traditionally did not maintain brucellosis may now be at risk due to recent population increases. In particular, some neighboring populations of Montana elk were 5-9 times larger in 2007 than in the 1970s, with some aggregations comparable to the Wyoming feeding-ground populations. Addressing the unintended consequences of these increasing populations is complicated by limited hunter access to private lands, which places many ungulate populations out of administrative control. Agency-landowner hunting access partnerships and the protection of large predators are two management strategies that may be used to target high ungulate densities in private refuges and reduce the current and future burden of disease.

Life History Parameters of Gulf Flounder (Paralichthys albigutta) From Northwest Florida

Age, growth, natural and total mortality, a length-weight relationship, reproductive seasonality, sex ratio, maturity, and reproductive potential by size were estimated for gulf flounder, Paralichthys albigutta, from northwest Florida. The study used a fishery-independent approach during three annual migratory spawning seasons to sample gulf flounder offshore (spearing by divers) and inshore (multipanel trammel nets). We found gulf flounder to be slightly smaller at L∞ than other paralichthids (using either von Bertalanffy or damped growth functions), but gulf flounder obtained larger sizes and older ages than previously thought for this species [females to 575 mm total length (TL) and age 7, males to 373 mm TL and age 11], probably due to offshore sampling targeting more of the adult component of the stock. Given the older age structure than previously noted for this species, gulf flounder maturity and mortality estimates were similar to values reported for other U.S. paralichthids. Gulf flounder exhibited fall-winter gonad development with all evidence pointing to spawning occurring offshore. We estimated batch fecundity and spawning frequency, but it was apparent that there was a seasonal effect for both of these parameters, with increased oocyte density and nearly daily spawning occurring by late October to November, the peak period of development, also reflected in the gonadosomatic index.

Consequences of insect herbivory on grape fine root systems with different growth rates

Herbivory tolerance has been linked to plant growth rate where plants with fast growth rates are hypothesized to be more tolerant of herbivory than slower-growing plants. Evidence supporting this theory has been taken primarily from observations of aboveground organs but rarely from roots. Grapevines differing in overall rates of new root production, were studied in Napa Valley, California over two growing seasons in an established vineyard infested with the sucking insect, grape phylloxera (Daktulosphaira vitifoliae Fitch). The experimental vineyard allowed for the comparison of two root systems that differed in rates of new root tip production (a 'fast grower', Vitis berlandieri x Vitis rupestris cv. 1103P, and a slower-growing stock, Vitis riparia x Vitis rupestris cv. 101-14 Mgt). Each root system was grafted with a genetically identical shoot system (Vitis vinifera cv. Merlot). Using minirhizotrons, we did not observe any evidence of spatial or temporal avoidance of insect populations by root growth. Insect infestations were abundant throughout the soil profile, and seasonal peaks in phylloxera populations generally closely followed peaks in new root production. Our data supported the hypothesis that insect infestation was proportional to the number of growing tips, as indicated by similar per cent infestation in spite of a threefold difference in root tip production. In addition, infested roots of the fast-growing rootstock exhibited somewhat shorter median lifespans (60 d) than the slower-growing rootstock (85 d). Lifespans of uninfested roots were similar for the two rootstocks (200 d). As a consequence of greater root mortality of younger roots, infested root populations in the fast-growing rootstock had an older age structure. While there does not seem to be a trade-off between potential growth rate and relative rate of root infestation in these cultivars, our study indicates that a fast-growing root system may more readily shed infested roots that are presumably less effective in water and nutrient uptake. Thus, differences in root tip production may be linked to differences in the way plants cope with roots that are infested by sucking insects.

Labor Market Rigidities and the Employment Behavior of Older Workers

The labor market is often asserted to be characterized by rigidities that make it difficult for older workers to carry out their desired trajectory from work to retirement. An important source of rigidity is restrictions on hours of work imposed by firms that use team production or face high fixed costs of employment. Such rigidities are difficult to measure directly. We develop a model of the labor market in which technological rigidity affects the age structure of a firm's work force in equilibrium. Firms using relatively flexible technology care only about total hours of labor input, but not hours of work per worker. Older workers with a desire for short or flexible hours of work are attracted to such firms. Firms using a more rigid technology involving team production impose a minimum hours constraint, and as a result tend to have a younger age structure. A testable hypothesis of the model is that the hazard of separation of older workers is lower in firms with an older age structure. We use matched worker-firm data to test this hypothesis, and find support for it. Specification tests and alternative proxies for labor market rigidity support our interpretation of the effect of firm age structure on the separation propensity. These results provide indirect but suggestive evidence of the importance of labor market rigidities.

Suitability of a young deciduous-dominated forest for American marten and the effects of forest removal

American marten (Martes americana (Turton, 1806)) are generally considered to be reliant upon and most successful in continuous late-successional coniferous forests. By contrast, young seral forests and deciduous-dominated forests are assumed to provide low-quality marten habitat, primarily as a result of insufficient structure, overhead cover, and prey. This study examined a moderate-density population of marten in northeastern British Columbia in what appeared to be comparatively low-quality, deciduous-dominated habitat, overgrown agricultural land primarily consisting of 30- to 40-year-old stands of regenerating trembling aspen (Populus tremuloides Michx.). Over 4 years, we monitored 52 radio-collared marten. The population appeared to be stable, as indicated by large numbers of adults, relatively constant densities, long-term residency of many individuals, low mortality rates, and older age structure. Relatively small home ranges (males, 3.3 km2; females, 2.0 km2) implied good habitat quality and prey availability. Shearing (removal of immature forest cover) of 17% of the study area resulted in home range shifts at the individual level but no detectable impact at the population level. Categorically, marten avoided nonforested cover types and preferred mature coniferous (>25% conifer) stands (7% of the study area) but otherwise appeared to use all forested stands relative to their availability, including extensive use of deciduous-dominated stands and deciduous stands <40 years of age. Thus, these young deciduous forests appeared to have sufficient structure, overhead cover, and prey to maintain moderate densities of resident marten on a long-term basis.

Snowshoe hare demography during a cyclic population low

1. Snowshoe hare (Lepus americanus Erxleben) populations were studied in south‐west Yukon during the low phase of the 10‐year population cycle. Food availability and predator abundance were manipulated in a factorial design to determine the importance of each factor in hare dynamics during this phase. 2. Food was abundant during the low phase, and snowshoe hares were not food limited. 3. Survival of hares was higher than at any other phase of the cycle, and predators were scarce, but >75% of hare deaths resulted from predation. 4. Food addition resulted in higher hare densities and better body condition than on control sites. There were no observable effects of food addition on population rate of increase, recruitment, survival or age structure. 5. Mammalian predator reduction resulted in higher hare densities, higher survival, better body condition and an older age structure. Relative to control populations, recruitment was lower and population rates of increase similar. 6. The joint manipulation of food addition + predator reduction had greater positive effects on hare density and body condition than either single factor manipulation. Survival was better than on control sites, and the age structure was older than on control sites. Population rates of increase were similar, but recruitment was higher on the control areas. 7. We conclude that snowshoe hare dynamics at the low of the cycle are dominated by the interaction of food and predation. Risk of predation also had indirect effects on snowshoe hare age structure and body condition.

Ethnic and Gender Divisions in the Work Force of Russia

Like the former Soviet Union, Russia is home to many ethnic groups. The Russian Federal Treaty of March 1992 was signed by 18 ethnically-based republics and 17 non-Russian ethnic districts. Ethnic groups within Russia vary considerably in levels of socioeconomic achievement, with groups having had unequal access to political resources and differing in their ability to take advantage of economic opportunities. The author analyzed newly available occupational data from the 1989 census in his study of ethnic and gender differences in the work force of Russia. Measurements are presented showing differences between the occupations of Russians and the next largest 11 ethnic groups, producing a clear hierarchy of groups. The extent of occupational gender differences within each ethnic group is measured and contrasted with the level of differences between ethnic groups. These data are important for showing potential sources of group conflict and for providing a baseline to measure changing forms of inequality which have been promoted by post-Soviet developments. Preliminary findings point to the existence of highly significant differences between Russia's ethnic groups, with the level of the differences closely paralleling measures of socioeconomic achievement. To determine more precisely the significance of group differences in employment, detailed occupational categories must be examined more closely. Currently available data, however, do not permit more rigorous measurements of discrimination. It is nonetheless clear that ethnicity in contemporary Russia is strongly related to occupational differences. The aggregate segregation of men from women was found to be very stable despite the substantial socioeconomic and cultural differences between ethnic groups. As a group, Jews were found to have extremely high levels of educational and occupational achievement and a comparatively far older age structure.

Reflections on Replacement

In the United States, the total fertility rate is about 1.9 births per woman, down from a peak of 3.2 a generation ago and below the replacement level of 2.1 children. The proportion of women who will never have children has risen from 8% a generation ago to approximately 18% in 1993. The increase in the proportion of women in the labor force, a proximate explanation of the recent decline in intended fertility, is expected to continue. The demographic consequence is declining population with an older age structure. A pronatalist policy to alleviate this outcome, through monetary transfers from taxpayers to potential parents, is not only unlikely to succeed, it is politically unfeasible. An alternative solution, immediately effective but politically unpalatable, would be a generous immigration policy. Even with replacement level fertility, the population is destined to become much older. This inevitable aging of the population should be countered by appropriate institutional transformations: 1) with lower fertility, a larger proportion of women will be available to participate in the labor force to generate taxes needed to support a larger number of pensioners; 2) the institutional practice of ascribing a dependent status to anyone above a particular age can be changed; 3) concerns that an older labor force will have an obsolete education (and fewer years of it) can be countered by changing access to education. Yet, the most serious question is not merely the net reproduction rate, but producing adequate numbers of new adult citizens with responsibility and technical training in the modern world. The fundamental process of socializing children may be jeopardized by replacing the full-time parent with the hired care-giver, the peer group, and the television set. The attenuation of the bonds between parent and child may devalue the worth of childbearing itself. These portentous consequences deserve consideration.

Effects of water stress on the leaf demography of Agropyron desertorum, Agropyron dasystachyum, Bromus inermis, and Stipa viridula

We examined the effect of water stress on leaf demography in four grass species known to differ in degree of drought resistance. Stress was imposed by growing plants in solution culture and lowering water potential of the solution either slowly, or rapidly, by the addition of polyethylene glycol. Rapid stress reduced the number of leaves by increasing leaf death rate and decreasing birth rate. Gradual stress reduced the number of leaves by temporarily decreasing leaf birth rate; death rate also decreased, partially compensating for the reduction in birth rate. Death rates were age specific; rapid stress had little effect on young leaves, and gradual stress increased leaf longevity to the greatest extent in those leaves that emerged immediately prior to the imposition of stress. As a result, plants subjected to rapid stress had a young leaf age structure, while plants subjected to gradual stress had an older age structure. Differences among species in tolerance to water stress were related in part to differences in leaf age structure. Species with a young leaf age structure exhibited less of an increase in leaf mortality in response to rapid stress, and more of an increase in leaf longevity in response to gradual stress than other species. Key words: drought tolerance, leaf turnover, leaf age structure, polyethylene glycol, leaf senescence.

Does Australia's low fertility matter?

The author discusses the future effects of below-replacement fertility in Australia. "Continued below-replacement fertility would lead to a smaller maximum population, followed by population decline and an even older age structure. This paper argues that there is no need to increase the population and that a more mature age structure promises a number of benefits. Population growth imposes further costs on the already stressed natural environment and on the cities, and no economic benefits clearly offset these costs." Government policy to promote migration into Australia as a means of encouraging population growth is compared to the possible impact of a pronatalist policy. The author argues that social policies designed to reduce hardships faced by mothers are inherently desirable even if their demographic effects are uncertain.