Estimates Of Longevity Research Articles

Reconstructing pre-colonial oyster demographics in the Chesapeake Bay, USA

Recent estimates of growth and mortality rates in extant Chesapeake Bay, USA oyster ( Crassostrea virginica) populations are used to quantify changes in both population abundance (dN/dT) and shell accretion (dS/dT) associated with modern population demographics. The demographics of oyster populations that would be required to maintain reef accretion rates commensurate with sea level rise over geological time frames are examined using estimates of oyster longevity in pre-colonial (pre -1600) times combined with parallel estimates of pre-disease endemic mortality. The analysis demonstrates that modern populations, with their disease related, age-truncated demographics, are generally not capable of maintaining and building biogenic reefs through accretion. Estimates of filtration rates associated with Chesapeake Bay oyster populations prior to 1600 considerably underestimate actual benthic-pelagic coupling during that period. Pristine oyster populations would have supported water column turnover rates on the order of minutes to hours. Thus, the spatial footprint of oyster reefs was limited by available productivity in the estuary. Accretion rate calculations for pristine (pre-1600) oyster reefs describe the intimate relationship between benthic-pelagic coupling and the presence or absence of oyster reefs and the associated communities.

Has Longevity in the U.S. Peaked?

This article enumerates the five factors that influence longevity, with its attendant impact on the life settlement industry. We are at the apex of the longevity growth curve. It may increase slightly over the next 10 years, and then it will drop quite dramatically in the following years. As longevity declines, to the extent professional longevity estimates used by the life settlement industry are reduced at a slower rate than the actual changes in longevity, investors in life settlements may see opportunities to arbitrage those longevity estimates and increase their yields. <b>TOPICS:</b>Financial crises and financial market history, legal and regulatory issues for structured finance

Clinical Performance of Art Restorations in Primary Teeth: A Survival Analysis

To assess the survival of Atraumatic Restorative Treatment (ART) restorations in primary teeth performed in a dental clinical setting. One hundred and five single-surface ART restorations placed in 56 preschool children (mean age 31 months) were included. Final-year dental students performed the restorations using standard ART procedures with hand instruments. A resin-modified glass ionomer cement (Vitremer 3M/ESPE) was used as a restorative material. Performances of the restorations were assessed directly by the ART evaluation criteria. Follow-up period ranged from 6 to 48 months. Survival estimates for restoration longevity were evaluated using the Kaplan-Meier method. Log-rank test (P < or = .05) was used to compare the success rates according to demographic and clinical characteristics of the restorations at baseline (age, sex, arch and segment). Mean and median estimate times of survival were 37 (95% CI: 32-42) months and 38 (95% CI: 29-47) months respectively. Success rates for ART restorations were 89%, 85% and 72% in 6 to 11, 12 to 24 and 25 to 48 months of evaluation respectively. Differences in success rates among demographic and clinical characteristics were not statistically significant. High survivals rates of the ART restorations found in this study seem to indicate the reliability of this approach as an appropriate treatment option for primary teeth in a clinical setting.

Extreme longevity in freshwater mussels revisited: sources of bias in age estimates derived from mark–recapture experiments

Summary1. There may be bias associated with mark–recapture experiments used to estimate age and growth of freshwater mussels. Using subsets of a mark–recapture dataset for Quadrula pustulosa, I examined how age and growth parameter estimates are affected by (i) the range and skew of the data and (ii) growth reduction due to handling. I compared predictions from von Bertalanffy growth models based on mark–recapture data with direct observation of mussel age and growth inferred from validated shell rings.2. Growth models based on a dataset that included observations from a wide range of length classes (spanning ≥ the upper 50% of the population length range) produced only slightly biased age estimates for small and medium‐sized individuals (overestimated by 1–2 years relative to estimates from validated shell rings) but estimates became increasingly biased for larger individuals. Growth models using data that included only observations of larger animals (&lt; the upper 50% of length range) overestimated age for all length classes, and estimated maximum age was two to six times greater than the maximum age observed in the population (47 years). Similarly, growth models using a left‐skewed dataset overestimated age.3. Reductions of growth due to repeated handling also resulted in overestimates of age. The estimated age of mussels that were handled in two consecutive years was as much as twice that of mussels that were handled only once over the same period. Assuming a constant reduction in the annual rate of growth, handling an individual for five consecutive years could result in an estimated age that is five times too high.4. These findings show that mark–recapture methods have serious limitations for estimating mussel age and growth. A previous paper (Freshwater Biology, 46, 2001, 1349) presented longevity estimates for three mussel species that were an order of magnitude higher than estimates inferred from shell rings. Because those estimates of extreme longevity were based on mark–recapture methods and subject to multiple, additive sources of bias, they cannot be considered accurate representations of life span and cannot be used to conclude that traditional methods of bivalve ageing by interpretation of shell rings are flawed.

Age, growth and mortality of black redhorse (Moxostoma duquesnei) and shorthead redhorse (M. macrolepidotum) in the Grand River, Ontario

Summary Despite comprising a large portion of riverine fish biomass, very little demographic information is available for redhorse sucker (Moxostoma spp.) populations in Ontario (Canada). Information is presented on size and age structure, growth, and mortality of black redhorse (M. duquesnei), a threatened fish species, and shorthead redhorse (M. macrolepidotum) in the Grand River, Ontario. Estimates of body condition, adult mortality, longevity, and maximum attained length were very similar for both species. However, the more abundant shorthead redhorse reached maturity at a smaller size and younger age and grew at a slower rate than the black redhorse. Compared to populations in more southerly parts of its range, Grand River black redhorse grew more slowly, matured later and at a larger size, reached a higher maximum length and age, and was characterized by lower adult mortality rates. Reflective of its central location in the species range, the age and length characteristics of the Grand River population of shorthead redhorse were intermediate of, and overlapped with, other sampled populations.

Physiological quality of hybrid maize seeds during containerized-dry storage with silica gel

Seed storage operations in the tropics would benefit from low input techniques that can maintain seed physiological quality for considerably long periods without investments in cooling. A study was conducted to evaluate seed vigour and estimate seed longevity in maize during dry storage with commercial desiccant (silica gel) at various levels of gel/seed ratios in air-tight containers under ambient tropical temperature. Seed moisture content (MC) was lowest indicating effective drying at 1:1 gel/seed (100 g of seed stored over 100 g of gel) and 1:2.5 gel/seed ratio (100 g of seed stored over 80 g of gel) during 2 trials set up in 2005 and 2006. After 4 months of storage, laboratory seed germination capacity and vigour variables were consistently higher (p<0.05) in seed lots stored at 1:1 and 1:2.5 gel/seed ratios than seed lots stored at 1:20, 1:10 and 0:1 gel/seed ratios in the 2 trials. Probit analysis of seed survival data from controlled deterioration (CD) tests showed that estimates of potential longevity were optimal at 1:2.5 gel/seed ratios in the two experiments. The results indicated the possibility of maintaining seed physiological quality in containerized-dry storage under ambient humid tropical storage conditions. Moreover, the storage system experimented in the study simulated a condition that eliminates labour involved in regenerating or drying silica gel, since silica gel was not changed throughout the storage period. Gel/seed ratios between 1:1 and 1:2.5 are recommended for direct application or in developing technology and equipment for containerized-dry seed storage in the humid tropics.

Age Estimates of Two Large Misty Grouper, Epinephelus mystacinus (Serranidae) from Bermuda with a Comparison of the Age of Tropical Groupers in the Western Atlantic

Misty grouper are known to attain at least 54 kg and 115 cm total length (TL) (Heemstra and Randall 1993) although a maximum size of 160 cm TL is reported (Appeldoorn et al. 1987, cited in www.FishBase.com). Recently, two specimens (152 and 157 mm TL) were landed by commercial fisherman from the edge of the Bermuda platform, providing documentation of the maximum size which may be attained by this species. There are no age and growth studies on misty grouper (Heemstra and Randall 1993; www.FishBase.com). Therefore, the age data presented here, although not validated, represent the first estimates of maximum longevity and support Campana’s (2005) statement that, “methods for validating ages of deep-sea fishes are urgently required.” We compared the age estimates of our misty grouper specimens with the age of a large wreckfish (45.5 kg) taken from a similar but deeper-water habitat. In addition, we provide a comparison of the maximum ages of 9 other species of grouper in the western Atlantic.

Finnish dentists’ perceptions of the longevity of direct dental restorations

Objectives. To evaluate Finnish dentists’ perceptions of the longevity of direct dental restorations; to assess the possible impacts of dentists’ characteristics on these perceptions; and to compare the present longevity estimates with those of recent European reports. Methods. A questionnaire to 592 general practitioners, systematically sampled from the Finnish Dental Association's membership list, was posted in April 2004 and data collection was finished by the end of June. The question “In general, what is your estimate for the mean age of restoration in permanent teeth?” pointed restorations: Class II and MOD composites and amalgam in a posterior tooth and Class III composites in an incisor. Dentists’ gender, main work, and year of graduation served as background information. Of the 339 (57%) respondents, only public and private dentists were included; 11 were excluded. Three studies fulfilled the inclusion criteria for recent reports on restoration longevity. Statistical evaluation was by one-way ANOVA, with p=0.05 as the level of significance. Results. The mean of the estimates for all types of composite was 9.0 years (SD 3.6; 95% CI 8.6–9.3) and 18.7 years for amalgam (SD 7.3; 95% CI 18.0–19.5). Male dentists gave longer estimates than female dentists for posterior composites, but shorter estimates for amalgam. Compared to public dentists, private dentists gave longer estimates for posterior composites. All estimates were longer than those reported in the recent literature. Conclusion. Dentists’ perceptions of posterior composite longevity are significantly longer among males than among females and among private than public sector dentists, and exceed the median longevity reported in recent studies.

Estimating fine root longevity in a temperate Norway spruce forest using three independent methods.

The importance of root systems for C cycling depends crucially on fine root longevity. We investigated mean values for fine root longevity with root diameter, root C/N ratio and soil depth using radiocarbon (14C) analyses in a temperate Norway spruce [Picea abies (L.) Karst.] forest. In addition, we applied sequential soil coring and minirhizotron observations to estimate fine root longevity in the organic layer of the same stand. The mean radiocarbon age of C in fine roots increased with depth from 5 years in the organic layer to 13 years in 40-60 cm mineral soil depth. Similarly, the C/N ratios of fine root samples were lowest in the organic layer with a mean value of 24 and increased with soil depth. Roots >0.5 mm in diameter tended to live longer than those being <0.5 mm in diameter. By far the strongest variability in fine root longevity estimates was due to the chosen method of investigation, with radiocarbon analyses yielding much higher estimates (5.4 years) than sequential soil coring (0.9 years) and minirhizotron observations (0.7 years). We conclude that sequential soil coring and minirhizotron observations are likely to underestimate mean fine root longevity, and radiocarbon analyses may lead to an overestimation of mean root longevity.

A BAYESIAN UNCERTAINTY ANALYSIS OF CETACEAN DEMOGRAPHY AND BYCATCH MORTALITY USING AGE‐AT‐DEATH DATA

Wildlife ecologists and managers are challenged to make the most of sparse information for understanding demography of many species, especially those that are long lived and difficult to observe. For many odontocete (dolphin, porpoise, toothed whale) populations, only fertility and age-at-death data are feasibly obtainable. We describe a Bayesian approach for using fertilities and two types of age-at-death data (i.e., age structure of deaths from all mortality sources and age structure of anthropogenic mortalities only) to estimate rate of increase, mortality rates, and impacts of anthropogenic mortality on those rates for a population assumed to be in a stable age structure. We used strandings data from 1977 to 1993 (n = 96) and observer bycatch data from 1989 to 1993 (n = 233) for the Gulf of Maine, USA, and Bay of Fundy, Canada, harbor porpoise (Phocoena phocoena) population as a case study. Our method combines mortality risk functions to estimate parameters describing age-specific natural and bycatch mortality rates. Separate functions are simultaneously fit to bycatch and strandings data, the latter of which are described as a mixture of natural and bycatch mortalities. Euler-Lotka equations and an estimate of longevity were used to constrain parameter estimates, and we included a parameter to account for unequal probabilities of natural vs. bycatch deaths occurring in a sample. We fit models under two scenarios intended to correct for possible data bias due to indirect bycatch of calves (i.e., death following bycatch mortality of mothers) being underrepresented in the bycatch sample. Results from the two scenarios were "model averaged" by sampling from both Markov Chain Monte Carlo (MCMC) chains with uniform probability. The median estimate for potential population growth (r(nat)) was 0.046 (90% credible interval [CRI] = 0.004-0.116). The median for actual growth (r) was -0.030 (90% CRI = -0.192 to +0.065). The probability of population decline due to added fisheries mortality, prior to management to reduce bycatch, was 0.690. Our approach takes into account multiple sources of uncertainty in data and process, and it provides posterior distributions for a rich set of demographic rate parameters that are unknown for most cetaceans. This method should be easily adaptable to other taxa for which fertility and age-at-death data are available.

Otolith microstructure analysis with OTC validation confirms age overestimation in Atlantic thread herring Opisthonema oglinum from north‐eastern Brazil

The daily periodicity of micro‐increments in the otoliths of Atlantic thread herring Opisthonema oglinum was demonstrated from juveniles injected with oxytetracycline and reared for up to 62 days. Micro‐increments ranged from 26 to 358 in the overall sample. Von Bertalanffy growth function (VBGF) using micro‐increment counts were: L∞= 337 mm fork length (LF) (s.e. = 31 mm); K = 1·2 (s.e. = 0·2) and t0= 0·04 years (s.e. = 0·01 years). The otolith‐based growth was corroborated using the LF frequency analysis. Observed lengths of increments were considered unsuitable for VBGF derivation, as no increase in size was obtained from them. Furthermore, the high percentage of unreadable otoliths suggests that increment analysis is unreliable for age estimation. Most growth occurs within the first year, differing from previous longevity estimates of 4–8 years. In contrast with published information, O. oglinum is a fast‐growing and short‐lived species.

The Old Ladies of the Seed Harvester ant Pogonomyrmex Rugosus: Foraging Performed by Two Groups of Workers.

We examined temporal polyethism in Pogonomyrmex rugosus, predicting a pattern of decreasing age from foragers to nest maintenance workers to individuals that were recruited to harvest a temporary food source. Nest maintenance workers were younger than foragers, as indicated by their heavier mass and lower mandibular wear. In contrast, recruited foragers were similar in mass to foragers but they displayed higher mandibular wear, suggesting that they were at least as old as foragers. Longevity estimates for marked individuals of these two latter task groups showed mixed results. Higher mandibular wear of recruited foragers suggests that they did not follow the normal sequence for temporal polyethism, but rather that they functioned as seed-millers, which should more quickly abrade their dentition. This would be the first demonstration of specialist milling individuals in a monomorphic seed-harvester ant.

Effects of experimental soil frost on the fine‐root system of mature Norway spruce

AbstractSoil‐frost events may influence the dynamics of fine roots and therefore affect root‐derived C fluxes to the soil. We studied the impact of soil frost on the fine‐root dynamics of Norway spruce (Picea abies [L.] Karst.) by a replicated snow‐removal experiment in a mature forest in SE Germany. Snow removal in the three treatment plots reduced soil temperature significantly with minima &lt;–5.5°C in the O layer while the snow‐covered control plots never reached temperatures below the freezing point. Sequential soil coring in the O layer at the beginning and at the end of the soil‐frost period as well as after thawing revealed that the soil frost treatment increased fine‐root mortality by 29%. However, enhanced fine‐root production in the snow‐removal plots nearly compensated for the fine‐root losses caused by low temperatures. These findings were confirmed by minirhizotron observations in the O layer and the upper 25 cm of the mineral soil showing that relative fine‐root loss was by far higher in the snow‐removal plots than in the control plots. Compensatory fine‐root production in the snow‐removal plots exceeded fine‐root production in the control plots during a period of 8 weeks after the soil frost application by 39% in the O layer while it was similar in both plot types in the mineral soil. Sequential coring and minirhizotron observations led to substantially different fine root–longevity estimates for the soil frost period. However, in both cases, the snow‐removal treatment was characterized by a significant reduction in root longevity indicating a faster fine‐root turnover. As a consequence, experimental soil frost enhanced the C input to the soil via root death at our study site by approx. 42 g m–2 and stimulated the C investment towards the root system of the spruce trees due to a higher sink activity.

Cognitive changes in again—the implications for us as anaesthetists

Aging is a universal and progressive physiological phenomenon clinically characterised by degenerative changes in: • The structure of organs and tissue • The functional capacity of organs and tissues Life span is an idealised, species-specific biologic parameter that quantifies maximum attainable age under optimal environmental conditions, whereas life expectancy describes an empirical estimate of typical longevity under prevailing or predicted circumstances. Advances in medical science and health care have changed this considerably over the last few decades.

Comparação do crescimento entre Callinectes sapidus (Crustacea, Decapoda, Portunidae) coletados em campo e mantidos em condições contoladas

Devido à falta de estruturas rígidas para determinação de idade em crustáceos, métodos que se baseiam na determinação de idade através da distribuição da freqüência de comprimentos são comumente utilizados. Neste trabalho, foi comparado o crescimento do siri-azul, Callinectes sapidus Rathbun, 1896, em laboratório e a partir de indivíduos de campo. Os indivíduos de laboratório, após a coleta, tiveram seu crescimento acompanhado individualmente. A temperatura foi mantida constante (25±2°C) e a salinidade a 20±5. Os indivíduos do campo foram coletados entre 2002 e 2004 em pontos pré-determinados no estuário da Laguna dos Patos, com rede de portas. A biometria, nos dois casos, constou da medida da largura da carapaça (LC mm). As estimativas das curvas de crescimento, segundo o modelo de Bertalanffy para os indivíduos de campo, foram obtidas pelo acompanhamento do deslocamento modal (MPA). O tamanho máximo de largura de carapaça utilizado foi mantido fixo em todas as análises (157,78 mm para fêmeas e 162,71 mm para machos). Para os indivíduos mantidos em laboratório, os parâmetros e a longevidade obtidos foram k=0,001/dia; t o=-1,53; longevidade de 3117 dias (8,5 anos) para machos e k=0,002/dia; t o=-29,5; longevidade de 2795 dias para fêmeas (7,7 anos). Os parâmetros de crescimento e a longevidade estimados para os animais coletados em campo foram k=0,004/dia; t o=-4,23; 1267 dias (3,5 anos) para machos e k=0,004/dia; t o=-3,71; 1260 dias (3,45 anos) para fêmeas. Foram encontradas diferenças significativas entre animais de laboratório e de campo, sugerindo que a espécie responde de forma diferente ao ambiente em que está inserida.

Longevity and Change in Shell Condition of Adult Male Snow Crab Chionoecetes opilio Inferred from Dactyl Wear and Mark‐Recapture Data

AbstractPostmolt longevity and changes in the shell condition and body integrity of male snow crab Chionoecetes opilio after their terminal molt were assessed through a mark‐recapture experiment and population censuses in a commercially unfished locality of eastern Canada. The experiment explored the value of dactyl wear as a quantitative measure and shell condition (SC; measured on a five‐stage scale) as a relative index of shell age. Males were recaptured up to 6 years after release. Much of the extensive variation in observed dactyl wear was explained by time at liberty (Δt) and male size, and the extent of change in SC was positively correlated with Δt. The conservative wear‐based estimate of male longevity was 7.7 years, a value 1‐3 years greater than previously estimated. Dactyl wear and recapture data confirmed that SC is a relative, albeit rough, index of shell age. Shell hardness was positively correlated with male size and peaked in stage 3 about 3.5 years after the terminal molt. The number of missing pereopods increased with shell age and SC stage and overall was negatively correlated with male size. The commercial value of adult males may be highest at 1‐4.5 years post‐terminal molt and the reproductive value at 2‐5.5 years.

Comparison of Delayed Female Mating on Reproductive Biology of Codling Moth and Obliquebanded Leafroller

Delay of mating was examined as a possible mechanism for population decreases associated with mating disruption for codling moth, Cydia pomonella L., and obliquebanded leafroller, Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae). We examined the effect of delaying female mating 0, 2, 4, or 6 d while holding male age constant on life table parameters of both species. We found that increasing delays in mating were accompanied by two responses: (1) an increase in the percentage of sterile pairs and (2) a reduction in net reproductive rate and population growth unrelated to sterility. On a percentage basis, obliquebanded leafroller population growth was more strongly affected than codling moth. However, the net fertility rate of obliquebanded leafroller was nearly eight-fold higher than that of codling moth, so that obliquebanded leafroller females that experienced a 4-d delay in mating had nearly the same reproductive rate as codling moth females that experienced no delay. Leslie matrix simulations using life tables with field-based adult longevity estimates showed that codling moth females experiencing >2-d delay in mating resulted in decreases in population density or extinction within two generations. In contrast, obliquebanded leafroller females delayed <6 d showed rapid population growth that decreased as female age at mating increased; only the 6-d delay treatment resulted in decreased population levels. Our results indicate that obliquebanded leafroller females must on average experience a much longer delay in mating to significantly reduce population growth compared with codling moth females, suggesting that delay of mating likely plays a greater role in codling moth mating disruption than for obliquebanded leafroller.

Using bomb radiocarbon analyses to validate age and growth estimates for the tiger shark, Galeocerdo cuvier, in the western North Atlantic

Refined and validated age and growth determinations are necessary for a proper understanding of tiger shark (Galeocerdo cuvier) life history characteristics in the western North Atlantic (WNA). Age and growth estimates were derived from band counts of 238-sectioned vertebral centra. Bomb radiocarbon analysis of ten band pairs extracted from four vertebral sections suggested that band pairs are deposited annually up to age 20. Males and females were aged to 20 and 22 years, respectively, although longevity estimates predict maximum ages of 27 and 29 years, respectively. Two- and three-parameter von Bertalanffy and Gompertz growth functions fit to length at age data demonstrated that growth rates were similar for males and females up to around 200 cm fork length (FL) after which male growth slowed. Both sexes appear to reach maturity at age 10. The two-parameter von Bertalanffy growth function provided the best biological fit to length at age data generating parameter estimates of: L∞ = 330 cm FL, k = 0.131 for males and L∞ = 347 cm FL, k = 0.124 for females, with L0 set at 62 cm FL. This study provides a rigorous description of tiger shark age and growth in the WNA and further demonstrates the utility of bomb radiocarbon as an age validation tool for elasmobranch fish.

Survival dynamics of scleractinian coral larvae and implications for dispersal

Survival of pelagic marine larvae is an important determinant of dispersal potential. Despite this, few estimates of larval survival are available. For scleractinian corals, few studies of larval survival are long enough to provide accurate estimates of longevity. Moreover, changes in mortality rates during larval life, expected on theoretical grounds, have implications for the degree of connectivity among reefs and have not been quantified for any coral species. This study quantified the survival of larvae from five broadcast-spawning scleractinian corals (Acropora latistella, Favia pallida, Pectinia paeonia, Goniastrea aspera, and Montastraea magnistellata) to estimate larval longevity, and to test for changes in mortality rates as larvae age. Maximum lifespans ranged from 195 to 244 d. These longevities substantially exceed those documented previously for coral larvae that lack zooxanthellae, and they exceed predictions based on metabolic rates prevailing early in larval life. In addition, larval mortality rates exhibited strong patterns of variation throughout the larval stage. Three periods were identified in four species: high initial rates of mortality; followed by a low, approximately constant rate of mortality; and finally, progressively increasing mortality after approximately 100 d. The lifetimes observed in this study suggest that the potential for long-distance dispersal may be substantially greater than previously thought. Indeed, detection of increasing mortality rates late in life suggests that energy reserves do not reach critically low levels until approximately 100 d after spawning. Conversely, increased mortality rates early in life decrease the likelihood that larvae transported away from their natal reef will survive to reach nearby reefs, and thus decrease connectivity at regional scales. These results show how variation in larval survivorship with age may help to explain the seeming paradox of high genetic structure at metapopulation scales, coupled with the maintenance of extensive geographic ranges observed in many coral species.

Estimated longevity and changes in spirituality in the context of advanced congestive heart failure

To examine (1) advanced congestive heart failure (CHF) patients' estimates of their longevity and changes in these estimates over time; (2) clinical, functional, and psychological adjustment correlates of these longevity estimates; and (3) correspondence of changes in longevity and changes in multiple dimensions of spirituality over time. Longitudinal questionnaire-based study of 111 patients diagnosed with severe CHF assessed at two time points separated by 6 months. Nearly half of the participants estimated their longevity as at least 5-10 years, and there was very little change in estimates across the assessment periods. Longevity estimates were minimally related to clinical or functional indicators, but longer estimates were related to fewer depressive symptoms and higher levels of life satisfaction. Multivariate regression analyses indicated that shifting longevity estimates toward less time or toward uncertainty was related to increases in religious life meaning and forgiveness and to decreased spiritual struggle over the 6-month interval. No effects were observed for daily spiritual experiences. Because very little is known about how individuals estimate their remaining life span, these results establish information regarding their basis (i.e., not clinical or functional) and stability, at least in the context of advanced heart failure. In addition, the notion that individuals become more spiritual as they perceive the approach of death was borne out in terms of multiple aspects of spirituality.