Patient age and long term survival of fixed prosthodontics

The possible relationship between patient age and the long term survival of fixed prostheses was studied in a randomised group of persons, who had received restorative treatment by general practitioners 13 years prior to this study. These fixed partial dentures had a mean extension of 6.9 units and a mean pontic/abutment ratio of 0.47. The group studied consisted of 77 persons who agreed to participate from an original group of 150 persons. Of the original group 20 had died, 17 were not traceable or unable to participate for medical reasons, and 36 declined to participate. The outcome of the treatment was compared between the following age subgroups (age as at the time of the original treatment) by division of the data at 37, 60 and 65 years. In these subgroups between 20 and 50 per cent of the prostheses had been lost or partially lost during the fifteen year period. Most of the failures and unacceptable quality ratings were found to be caused by fractures, loss of retention and/or dental caries. However, no systematic differences were found between any of the age subgroups studied.     

Assessing chimpanzee personality and subjective well‐being in Japan

We tested whether the cultural background of raters influenced ratings of chimpanzee personality. Our study involved comparing personality and subjective well‐being ratings of 146 chimpanzees in Japan that were housed in zoos, research institutes, and a retirement sanctuary to ratings of chimpanzees in US and Australian zoos. Personality ratings were made on a translated and expanded version of a questionnaire used to rate chimpanzees in the US and Australia. Subjective well‐being ratings were made on a translated version of a questionnaire used to rate chimpanzees in the US and Australia. The mean interrater reliabilities of the 43 original adjectives did not markedly differ between the present sample and the original sample of 100 zoo chimpanzees in the US. Interrater reliabilities of these samples were highly correlated, suggesting that their rank order was preserved. Comparison of the factor structures for the Japanese sample and for the original sample of chimpanzees in US zoos indicated that the overall structure was replicated and that the Dominance, Extraversion, Conscientiousness, and Agreeableness domains clearly generalized. Consistent with earlier studies, older chimpanzees had higher Dominance and lower Extraversion and Openness scores. Correlations between the six domain scores and subjective well‐being were comparable to those for chimpanzees housed in the US and Australia. These findings suggest that chimpanzee personality ratings are not affected by the culture of the raters. Am. J. Primatol. 71:283–292, 2009. © 2009 Wiley‐Liss, Inc.     

An elusive paleodemography? A comparison of two methods for estimating the adult age distribution of deaths at late Classic Copan,Honduras

Comparison of different adult age estimation methods on the same skeletal sample with unknown ages could forward paleodemographic inference, while researchers sort out various controversies. The original aging method for the auricular surface (Lovejoy et al., 1985a) assigned an age estimation based on several separate characteristics. Researchers have found this original method hard to apply. It is usually forgotten that before assigning an age, there was a seriation, an ordering of all available individuals from youngest to oldest. Thus, age estimation reflected the place of an individual within its sample. A recent article (Buckberry and Chamberlain, 2002) proposed a revised method that scores theses various characteristics into age stages, which can then be used with a Bayesian method to estimate an adult age distribution for the sample. Both methods were applied to the adult auricular surfaces of a Pre-Columbian Maya skeletal population from Copan, Honduras and resulted in age distributions with significant numbers of older adults. However, contrary to the usual paleodemographic distribution, one Bayesian estimation based on uniform prior probabilities yielded a population with 57% of the ages at death over 65, while another based on a high mortality life table still had 12% of the individuals aged over 75 years. The seriation method yielded an age distribution more similar to that known from preindustrial historical situations, without excessive longevity of adults. Paleodemography must still wrestle with its elusive goal of accurate adult age estimation from skeletons, a necessary base for demographic study of past populations.     

Quantification of the Effects of Age on the Dose Response of Variola major in Suckling Mice

Dose-response data for Variola major (V. major), the causative agent of smallpox, were obtained from the open literature, summarized, and fitted with three dose-response models. It is known from prior outbreak experience that there is generally a difference in infectivity of the agent and its subsequent mortality depending on the age of the patient. A source of animal dose-response data were found with age delineation for the exposure group (suckling mice, intraperitoneal exposure). This delineation was used to adapt current dose-response models to include an age dependency parameter. The degree of the models' fit to the data was ascertained using maximum likelihood estimation (MLE). The effect of host age could be described quantitatively using modifications to the beta Poisson and exponential dose-response models. The modifications improvement in the accuracy of risk prediction by 72% for the beta Poisson model and 7% for the exponential model, compared to the original (unmodified) models.     

The coarse‐root system of mature Populus tremuloides in declining stands in Alberta,Canada

Abstract. The coarse‐root dynamics of ramets of Populus tremuloides (aspen) were investigated with respect to persistence of the original root connections (roots of parent trees from which the ramets originated), the time of establishment of new roots at the base of the stem and the fate of the communal root system after death of individual trees. Parts of the root systems of three declining stands of aspen ramets were hydraulically excavated. From each stand, sections of all structural roots were collected at the base of live and dead trees and were analysed using dendrochronology techniques. Parent roots were identified in the root system of every tree. The trees initiated new structural roots shortly after suckering. Live roots were often connected to the stump of dead and decayed trees. Grafting was common, especially at or near the stumps. Death of trees along the parent roots over time did not seem to favour the entry of significant decay, nor promote breakage of the original root connections. Instead of becoming independent of the parent root system the ramets incorporated the parent roots into their own root systems, remaining interconnected.     

Changes in ant communities along an age gradient of cocoa cultivation in the Oumé region,central Côte d'Ivoire

We identified the extent to which ant diversity occurs despite conversion of forests into cocoa plantations by examining the communities across four age classes of plantations (classes I–IV with increasing age from 0–5 to 21–40 years) and in their original forests. An extensive sampling protocol consisting of pitfall trapping, leaf litter sampling, soil sampling and hand sampling was used to characterize ant species richness and composition in three replicates of each age class and in the remaining forest patches. A total of one hundred ant species was found in all habitats combined. While the forest was the richest habitat (73 species), species richness in the different plantation age classes varied as follows (sorted in descending order): class IV (69 species) > class III (57 species) > class I (52 species) > class II (43 species). Age gradient was thus significantly positively correlated with mean species richness and with the relative abundance of some subfamilies. The species composition differed greatly between some plantation age classes and the forest. The two youngest cocoa age classes (I and II) were most dissimilar to the forest. In contrast, forest ants were well represented in the old cocoa age classes (III and IV). Three functional guilds (generalist predators, specialist predators and territorially dominant arboreal species) were in their relative abundance significantly correlated to the age gradient. Overall, cocoa cultivations retaining a floristically diverse and structurally complex forest structure are a suitable management system for the conservation of ant species of the formerly forested habitats.     

Effects of rhizome age on the decomposition rate of Phragmites australis rhizomes

The change in dried rhizome samples that were left to decompose was investigated to elucidate the effects of rhizome age on the decomposition rate of Phragmites australis. Rhizomes were classified into five age categories and placed 30 cm below the soil surface of a reed stand. After 369 days of decay, new (i.e., aged less than one year) rhizomes had lost 84% of their original dry mass, compared with a loss of 41–62% for that of older rhizomes. The exponential decay rates of older rhizomes were nearly identical to that of aboveground biomass. The nitrogen (N) concentration increased to two times its original values, but the phosphorus (P) concentration remained constant after an initial loss by leaching. The carbon to nitrogen (C:N) and carbon to phosphorus ratios (C:P) leveled out at 22:1 to 38:1 and 828:1 to 1431:1, respectively, regardless of rhizome age. The results are important to understand the nutrient cycles of reed-dominant marsh ecosystems.     

Problems in determination of skeletal lead burden in archaeological samples: an example from the First African Baptist Church population

Human bone lead content has been demonstrated to be related to socioeconomic status, occupation and other social and environmental correlates. Skeletal tissue samples from 135 individuals from an early nineteenth century Philadelphia cemetery (First African Baptist Church) were studied by electrothermal atomic absorption spectrometry and X-ray fluorescence for lead content. High bone lead levels led to investigation of possible diagenetic effects. These were investigated by several different approaches including distribution of lead within bone by X-ray fluorescence, histological preservation, soil lead concentration and acidity as well as location and depth of burial. Bone lead levels were very high in children, exceeding those of the adult population that were buried in the cemetery, and also those of present day adults. The antemortem age-related increase in bone lead, reported in other studies, was not evidenced in this population. Lead was evenly deposited in areas of taphonomic bone destruction. Synchrotron X-ray fluorescence studies revealed no consistent pattern of lead microdistribution within the bone. Our conclusions are that postmortem diagenesis of lead ion has penetrated these archaeological bones to a degree that makes their original bone lead content irretrievable by any known method. Increased bone porosity is most likely responsible for the very high levels of lead found in bones of newborns and children.     

Characteristics of Cats Admitted to Czech Shelters

The aim of this study was to describe the numbers and characteristics of cats entering Czech shelters. Records of sheltered cats were collected from three cat shelters situated in different regions of the Czech Republic from 2011 to 2015. A total of 2170 cat admissions were analyzed in this study. Significantly (p < .001) greater numbers of females (56%) were admitted. Most cats (60%) were admitted when they were aged younger than six months. Cats with dark coat colors prevailed (73%), cats with medium-shade colors followed (20%), and light-colored cats were the rarest (7%). The greatest numbers of cats were admitted in summer (36%), followed by autumn (33%). The fewest cats were admitted in winter (14%). Adoption was the most common outcome for admitted cats (65%), followed by unassisted death (22%) and euthanasia (11%) due to health reasons. Only 2% of cats were reclaimed from the shelters by their original caretakers. The length of stay ranged from 0 days to 1736 days with a median of 45 days. These findings may help shelter operators define optimal strategies and operational plans.     

Comparison of fresh to fixed weights of the vervet monkey (Chlorocebus sabaeus) placenta and its relation to gestational age

Background Focus on the placenta as an agent of fetal development and offspring health outcomes is growing. Primate research facilities or zoos may collect and fix placental tissue for long‐term storage, but little is known about the effects of formalin fixation on the non‐human primate placenta. Methods We obtained 48 vervet monkey placentas from the St. Kitts Biomedical Research Foundation. We investigated via correlation coefficients and ANOVAs the effects of gestational age and original fresh weight on weight change due to fixation. We also used linear regression models to determine whether fixed tissue weight was predictive of fresh weight and gestational age. Results Although the vervet monkey placenta is described as bidiscoid, 14.6% of the placentas in this sample were fused into a single mass. A decrease in weight was the most common response to formalin fixation, with the greatest degree of loss experienced by the heaviest placentas (ANOVA, F = 5.99, P = 0.005). Gestational age was unrelated to weight change. Those placentas that increased in weight had the lowest fresh weights. Fixed weights significantly predicted both fresh weight and gestational age (r² = 0.78, P < 0.00001; r² = 0.76, P < 0.00001, respectively). Conclusions This paper adds to a sparse literature on the vervet monkey placenta. That fixed placentas are excellent predictors of both fresh weight and gestational age suggests that banked tissue may be a valuable resource for reconstructing aspects of individual life history, although caution must be exercised given the variability of weight change as a function of original placental size.     

In vitro flower induction in roses

Summary Vegetatively propagated plantlets of six rose cultivars were induced to flower in vitro on media containing full-strength Murashige and Skoog (MS) inorganic salts, Gamborg's B5 organic elements with 400 mg l⁻¹ myo-inositol, and different phytohormone combinations of 6-benzyladenine (BA) with α-naphthaleneacetic acid (NAA); thidiazuron (TDZ) with NAA; and zeatin (ZT) with NAA. The most efficient flower bud induction (49.1% and 44.1%) was obtained on media supplemented with 0.5 mg l⁻¹ (2.27 μM) TDZ and 0.1 mg l⁻¹ (0.54 μM) NAA or 0.5 mg l⁻¹ (2.28 μM) ZT and 0.1 mg l⁻¹ (0.54 μM) NAA for cultivar Orange Parade. Scanning electron microscopy (SEM) showed that in vitro flower bud induction occurred mostly between 15 and 30 d in induction medium through the normal flower development processes. With TDZ and ZT as the best choice for flower induction in all six cultivars tested, different rose cultivars varied in their responses to phytohormone treatments. Our study also revealed that the total time from original culture and subculture time before flower induction were two very important factors for in vitro flower induction. Plantlets 156–561 d from original culture and subcultured for 45 d were the best for flower induction. These authors contributed equally to this work.     

Differences in clinical manifestations of influenza-associated encephalopathy by age

Data from patients in Japan was analyzed to examine the age distribution and differences by age in the clinical manifestations of influenza-associated encephalopathy. Between 1998 and 2002, 472 cases of influenza-associated encephalopathy in patients aged 15 years or younger were reported to the Collaborative Study Group on Influenza-Associated Encephalopathy. These cases were divided into two groups by age: 0–5 and 6–15 years. The differences between the groups were estimated based on the data for those aged 0–5 years, and the odds ratios and 95% confidence intervals calculated. Distribution was inversely correlated with age, with a peak at 1–2 years old. In comparison with patients aged 0–5, those aged 6–15 years had a significantly greater incidence of type B infection, lower frequency of convulsions, higher frequency of loss of consciousness and altered consciousness as the initial neurological symptom, lower serum transaminase levels, lower frequency of low-density area for brain CT upon admission, and lower incidence of sequelae. Our analysis indicates that the clinical course, laboratory data, and brain imaging findings of influenza-associated encephalopathy exhibits patterns that vary with age.     

A landscape‐based approach for assessing spatiotemporal impacts of forest biomass‐based electricity generation on the age structure of surrounding forest plantations in the Southern United States

Forest plantations support several ecosystem services including biodiversity conservation. Establishment of a forest biomass‐based industry could significantly change the age structure of forest plantations located in its vicinity and thus, could lead to a possible loss of biodiversity. Therefore, this study assesses spatiotemporal impacts of a forest biomass‐based power plant on the age structure of surrounding forest plantations at landscape level. A cellular automata approach was adopted and interactions between economic objectives of forest landowners and a power plant owner punctuated by forest growth and management characteristics were considered. These spatiotemporal impacts were jointly assessed for four separate scenarios and four different power plant capacities using appropriate landscape‐level indices. Slash pine (Pinus elliotti L.) was selected as a representative species. Results indicate that the age structure of surrounding forest plantations continuously fluctuates with respect to each year of power plant operation. However, the age structure, once disturbed, never becomes comparable to the original age structure. We also found that the mature plantations were harvested during early years of power plant operation and were never observed again for the remaining years of power plant operation. This was particularly true for high capacity power plants. Similarly, high value of selected spatial index at the end of power plant life for a high capacity power plant relative to the original low value of the same index indicates aggregation of remaining plantation ages at landscape level. Establishment of low capacity forest biomass‐based power plants and adoption of an integrated regional level planning approach could help in maintaining original age structure characteristics of surrounding forest plantations to a large extent. This might help in sustaining various ecosystem services including biodiversity conservation obtained from forest plantations in a long run.     

Some regularities of population structure and dynamics variability in bream <Emphasis Type="Italic">Abramis brama</Emphasis> in water bodies of Eastern Europe

Structure and dynamics of populations of bream Abramis brama inhabiting water bodies of Eastern Europe of different types are investigated. With the consideration of the original and published data, the following issues are analyzed in populations from the southern part of the area (water bodies of Moldova) and from the central and northwestern areas of the European part of Russia: age composition, sex ratio, males and females growth in size and weight, and age of maturation. Over the area, all transitions from short-cycle populations to average-cycle and long-cycle populations are observed. The maximum longevity of their specimens attains 9, 15, and 26 years, respectively. The growth rate of bream is controlled by a combination of average temperature, duration of vegetation season, size of water body, number of trophic niches for various size-weight groups, multiple change of the kind of feeding in ontogenesis, and general availability of food for adults. From the north to the south the variation of maturation age and of the rate of size and weight growth increase.     

Estimating fluctuating selection in age-structured populations

In age-structured populations, viability and fecundity selection of varying strength may occur in different age classes. On the basis of an original idea by Fisher of weighting individuals by their reproductive value, we show that the combined effect of selection on traits at different ages acts through the individual reproductive value defined as the stochastic contribution of an individual to the total reproductive value of the population the following year. The selection differential is a weighted sum of age-specific differentials that are the covariances between the phenotype and the age-specific relative fitness defined by the individual reproductive value. This enables estimation of weak selection on a multivariate quantitative character in populations with no density regulation by combinations of age-specific linear regressions of individual reproductive values on the traits. Demographic stochasticity produces random variation in fitness components in finite samples of individuals and affects the statistical inference of the temporal average directional selection as well as the magnitude of fluctuating selection. Uncertainties in parameter estimates and test power depend strongly on the demographic stochasticity. Large demographic variance results in large uncertainties in yearly estimates of selection that complicates detection of significant fluctuating selection. The method is illustrated by an analysis of age-specific selection in house sparrows on a fitness-related two-dimensional morphological trait, tarsus length and body mass of fledglings.     

Co-invading ectomycorrhizal fungal succession in pine-invaded mountain grasslands

Ectomycorrhizal (EM) fungal communities that associate with invading pines (Pinus spp.) are expected to be poor in species diversity. However, long-term successional trajectories and the persistence of dispersal limitations of EM fungi in the exotic range are not well understood. We sampled the roots and surrounding soil of Pinus elliottii and P. taeda trees invading mountain grasslands of Argentina. We also sampled the EM fungal spore bank in grassland soil near (∼150 m) and far (∼850 m) from the original pine plantations. We found 86 different co-invasive EM fungal OTUs. Differential dispersal capacities among EM fungi were detected in the spore bank of grassland soil, but not under mature pines. After thirty years of invasion, the age, but not the degree of spatial isolation of pine individuals affected the EM fungal composition. We showed how EM fungal succession occurs during pine invasions, which may have clear consequences for ecosystem functioning of co-invaded sites.     

仙湖苏铁种群年龄判断及年龄结构特征

根据苏铁类植株体残存的营养叶叶基数、开花痕数以及生长单元发生率等茎干特征, 建立了仙湖苏铁种群年龄判断方法,计算出该种群年龄. 进一步采用年龄结构图、年龄分布 曲线和曲线估计等方法,从基株和无性系水平探讨了仙湖苏铁种群的年龄结构特征.年龄结构 图显示,仙湖苏铁无性系种群为稳定种群,基株种群为衰退种群;年龄分布曲线和曲线估计结 果则表明仙湖苏铁无性系和基株种群均为衰退种群. 综合3种方法的分析结果,仙湖苏铁 种群为衰退种群,必须采取一定措施予以保护.     

A new method for estimating age-at-death from the first rib

A new method for estimating adult age-at-death from the first rib was developed as a modification of the Kunos et al. (Am J Phys Anthropol 110 (1999) 303-323) method. Data were collected on three aspects of the first rib (costal face, rib head, and tubercle facet) for 470 known-age males of Balkan ancestry collected as evidence during investigations conducted by the International Criminal Tribunal for the former Yugoslavia (ICTY). Ages-at-death range from 12 to 90 years (mean of 47.7 years). Several variables were extracted from the original study utilizing all three skeletal aspects of the first rib. This list was modified to 11 variables as preliminary tests on seriations of the samples were undertaken. A cumulative probit model with age measured on a log scale was used to calculate the mean and standard deviation of the ages-of-transition for each component. Multivariate analysis of the three components was also performed. The lowest correlation (r = 0.079, controlling for age) was between the geometric shape of the costal face and the surface texture of the tubercle facet. Assuming a correlation of zero, these two traits were used to calculate the highest posterior density regions for estimating individual ages-at-death. Age-at-death estimates generated from 50 and 95% posterior density regions indicate that this method captures age-related change reaching the ninth decade. The Bayesian statistical approach used here produced a valuable and promising new method for estimating age-at-death. Additional research is necessary to determine if these highest posterior density regions produce results highly correlated with age in other samples and its applicability to females.     

Age validation and growth of three commercially important hemiramphids in south-eastern Australia

The method of using sectioned otoliths to estimate age in three species of garfishes (family Hemiramphidae) was validated by: (1) staining fishes with the vital stain alizarin complexone (ALC) and periodically examining their otolith growth, and (2) marginal increment analyses. Staining fishes with ALC indicated that opaque zones were formed during winter and spring, but did not become visible on the otolith edge until late spring and summer. Hyporhamphus australis were found to be similar to the hemiramphids of the Atlantic in having fast growth rates and a maximum observed age of 4+ years old. Hyporhamphus regularis ardelio and Arrhamphus sclerolepis krefftii were found to be more similar to the southern sea garfish, Hyporhamphus melanochir , in being moderately long-lived, with maximum observed ages of 7+ years old for both species. Females grew faster and attained greater fork lengths than males for each species. Sectioned otoliths showed large variation in the appearance of opaque zones between the three species studied, with those from the wide-ranging, oceanic H. australis appearing inconsistent and diffuse when compared to the estuarine H. r. ardelio and A. s . krefftii . This variation was also apparent from fishes kept in aquaria, suggesting that the appearance of opaque zones in otoliths of these species is largely influenced by physiology, rather than by environmental conditions.