Considerable Variation In Age Research Articles

Atlantic salmon (Salmo salar) age at maturity is strongly affected by temperature, population and age-at-maturity genotype.

Age at maturity is a key life history trait involving a trade-off between survival risk and reproductive investment, and is an important factor for population structures. In ectotherms, a warming environment may have a dramatic influence on development and life history, but this influence may differ between populations. While an increasing number of studies have examined population-dependent reactions with temperature, few have investigated this in the context of maturation timing. Atlantic salmon, a species of high conservation relevance, is a good study species for this topic as it displays considerable variation in age at maturity, of which a large proportion has been associated with a genomic region including the strong candidate gene vgll3. Until now, the effect of this gene in the context of different environments and populations has not been studied. Using a large-scale common-garden experiment, we find strong effects of temperature, population-of-origin, and vgll3 genotype on maturation in 2-year-old male Atlantic salmon (Salmo salar). With a temperature difference of 1.8°C, maturation probability was 4.8 times higher in the warm treatment than the cold treatment. This temperature effect was population-specific and was higher in the southern (60.48°N) compared to the northern (65.01°N) population. The early maturation vgll3*E allele was associated with a significantly higher maturation probability, but there was no vgll3 interaction with temperature or population. Both body condition and body mass associated with maturation. The body mass association was only present in the warm treatment. Our findings demonstrate that (i) populations can vary in their response to temperature change in terms of age at maturity, (ii) high intrinsic growth could be associated with higher thermal sensitivity for life history variation and (iii) vgll3 effects on age at maturity might be similar between populations and different thermal environments.

Factors affecting age at primiparity in black bears

AbstractEffective wildlife management requires an understanding of the factors affecting population vital rates. Age at primiparity can be an important determinant of population growth rates. Thus, understanding the factors influencing age at primiparity in wild populations is important for their management and conservation. American black bears (Ursus americanus) are widely distributed in North America and show considerable variation in age at primiparity across their range. We tested hypotheses regarding top‐down and bottom‐up drivers of age at primiparity in black bears across the province of Ontario, Canada. We obtained estimates of age at primiparity using cementum patterns in 1,033 bear teeth collected as part of regulated harvest in 2018 and 2019. We compared mean ages at primiparity between 2 distinct forest regions in Ontario using a Wilcoxon test. To quantify the effects of multiple putative drivers of variation in primiparity (e.g., harvest density, food availability, land use, climate), we paired yearly probability of primiparity data with environmental covariates in a mixed effects logistic regression model. Age at primiparity was significantly lower in the more productive forest region, likely reflecting broad‐scale patterns of food availability. Further, there was a significant positive effect of growing degree days (annual sum of daily mean degrees >5°C) on probability of primiparity, likely related to its influence on ecosystem productivity. Harvest density was negatively related to the probability of primiparity, possibly because harvest is positively correlated with bear density at this broad scale, and competition for food resources increases with bear density. Overall, temporal variation in food availability had a positive effect on probability of primiparity in a model fit to data for which we had the highest confidence in age estimates from cementum. Mean age at primiparity was older (5.57 yr) than in other more southernly populations, and most harvested bears (53%) were harvested prior to reproducing. Our analysis suggests that black bear age at primiparity is primarily driven by bottom‐up forces related to climate and vegetation differences that lead to greater food availability in the south. The relatively old age at primiparity and high apparent mortality rate of young animals in this population suggests that harvest can limit recruitment substantially, which needs to be considered when making management decisions.

Accuracy of estimating age from eruption levels of mandibular teeth

Little is documented on the accu-racy of estimating age from alveolar eruption (AE) or partial eruption (PE). The aim of this study was to compare the accuracy of age estimation from eruption levels. Methods tested were Gleiser and Hunt (1955), Garn et al. (1958), Ando et al. (1965), Haavikko (1970) and clinical eruption from Smith et al. (1998). The sample was 946 panoramic dental radiographs from children aged 3-16 years. Left mandibular teeth (excluding third molar) were assessed for eruption level (AE and PE) and root quarters. Methods, teeth and eruption levels were deemed to be accurate if the average difference between estimated and chronological ages was not significant to zero using a t-test (P>0.05). Results show that early erupting permanent teeth were fairly good at estimating age, although there was considerable age variation in eruption. Haavikko incisors and molars at AE and Haavikko and Smith central incisor and second molar at PE estimated age accurately. Root stage of erupting teeth estimated age more accurately than eruption level using Haavikko. These findings suggest that erupting permanent mandibular teeth can be helpful in estimating age.

What Are the Unmet Needs and Care Experiences of Adolescents and Young Adults with Cancer? A Systematic Review.

To assess what is currently known about unmet needs and care experiences of adolescents and young adults (AYAs) with cancer, identify gaps in the research literature, and highlight potential areas for improvement in future research. Medline, PsycINFO, CINAHL, and EMBASE databases were searched to identify relevant studies from 1990 to July 2015. Eligible articles included self-reported care experiences or unmet needs of cancer patients aged between 15 and 30 years in the period between symptom onset and 2 years post-treatment. Qualitative and quantitative designs were included. Forty-five articles from 39 studies (23 qualitative, 12 quantitative, and 4 mixed methods) were rated as "adequate" or "good" quality and reviewed. The majority included any cancer diagnoses and none was longitudinal. There was considerable variation in age ranges and time since diagnosis between studies. Only two studies used standardized survey tools, with both tools validated on adult populations. The most common areas assessed for care experiences and needs were information/communication and fertility. In addition, care experience studies commonly examined clinical expertise and age-appropriate settings, while unmet needs studies reported on emotional support and peer interaction. Findings highlight the need for age-appropriate information and treatment facilities, access to emotional support services, and contact with peers. Fertility information and services are a priority issue for this group. Future research would benefit from a consistent definition of the AYA age range, increased used of standardized scales validated with this population, and longitudinal designs to assess changes over time.

Normal Variation in Pubertal Timing: Genetic Determinants in Relation to Growth and Adiposity.

In humans, there is a considerable variation in age of onset of puberty. Twin studies have indicated that pubertal timing is a highly heritable trait. Recently, a few rare genetic causes of precocious puberty have been reported as well as genetic mutations associated with isolated hypogonadotropic hypogonadism. Genome-wide association (GWA) studies have helped to explore the genetic determinants of the normal variation in pubertal timing, but have been able to explain only 2.7% of the variance in age at menarche, highlighting the involvement of multiple genes with small effect sizes. These studies indicate an overlap of genes involved in pubertal timing and adiposity, and epidemiological data suggest the existence of a pathway of early infancy weight gain, increased height gain in childhood, earlier pubertal timing and increased adiposity in adulthood. This chapter summarises the data from GWA and epidemiological studies on the normal variation in pubertal timing in relation to growth and adiposity. We discuss putative mechanisms linking early life events to pubertal timing, potential short-term and life-course consequences of earlier pubertal timing, and the impact of these data on clinical management of pubertal disorders.

Child's verbal ability and gender are associated with age at diagnosis in a sample of young children with ASD in Europe.

Autism spectrum disorder can in some cases be reliably diagnosed by age 2 years, but in community settings, the mean age at diagnosis is often considerably higher. Later diagnosis has been found to be associated with lower symptom severity, lower parental socioeconomic status and fewer parental concerns. Gender differences in age at diagnosis have been examined, with mixed evidence. We examined the association of child's verbal ability and gender, and parental education, with age at diagnosis in a large sample of young children with autism spectrum disorder in 18 European countries (n = 1410). There was considerable variation in age at diagnosis across countries. Children with better communication skills were diagnosed significantly later than non-verbal and minimally verbal children. There was also a significant interaction of gender with verbal ability on age at diagnosis, in that female children with complex phrase speech were diagnosed later than male children with the same level of verbal ability. Our findings highlight the need to implement public awareness initiatives and training for professionals to promote early detection and, consequently, early intervention for autism spectrum disorder in Europe.

Age at First Drink, Drinking, Binge Drinking, and DSM‐5 Alcohol Use Disorder Among Hispanic National Groups in the United States

This article examines age at first drink and adult drinking, binge drinking and DSM-5 alcohol use disorder (AUD) among U.S. Hispanic national groups. Respondents come from 2 independent studies. The Hispanic Americans Baseline Alcohol Survey used a multistage cluster sample design to interview 5,224 individuals 18 years of age and older selected from the household population in Miami, New York, Philadelphia, Houston, and Los Angeles. Respondents in the border area (N = 1,307) constituted a household probability sample of Mexican Americans living on U.S. counties that border Mexico. In both surveys, data were collected during computer-assisted interviews conducted in respondents' homes. The Hispanic American Baseline Alcohol Survey and the border sample response rates were 76 and 67%, respectively. U.S.-born Hispanics begin drinking at a younger age than those who are foreign-born, independent of national group. Among foreign-born Hispanics, age of arrival in the United States is not associated with age at first drink. Results support the hypothesis that a younger age at first drink is associated with a higher mean volume of drinking, a higher probability of bingeing, and a higher probability of DSM-5 AUD. But the results do not show a clear pattern by which a particular national group would consistently show no associations or stronger associations between age at first drink and the alcohol-related outcomes under consideration. An earlier age at first drinking is positively associated with heavier drinking patterns among U.S. Hispanics. However, as in other areas of alcohol epidemiology, here too there is considerable variation in age at first drink and drinking across Hispanic national groups.

Season of birth, crawling onset, and motor development in 7-month-old infants

Objective: To examine seasonal effect on motor development; in particular, the onset of crawling. Background: The acquisition of motor milestones demonstrates considerable age variation. Previous studies that examined the effect of season on motor development present inconsistent findings; geographical zone and climatic factors were among the identified factors. The present study was conducted in a Mediterranean climate. Method: Forty-seven full-term infants (25 boys and 22 girls), aged 7 months, were observed while playing in the home context, and the Alberta Infant Motor Scale (AIMS) was administered. Results: Infants who were born during the winter–spring (W) months started to crawl about 4 weeks earlier compared to infants born during the summer–autumn (S) months (t = 3.13, p = 0.003). Similarly, the AIMS total scores (t = 2.03, p = 0.05) and prone subscale (t = 2.19, p = 0.04) were significantly higher in W as compared to S born infants. Conclusion: The findings point to the involvement of season in the motor achievements of infants and suggest that aspects of the physical environment shape the experiences that contribute to developmental progress.

Late Cretaceous calcareous nannofossil and planktonic foraminiferal bioevents of the shallow-marine carbonate platform in the Mitla Pass, west central Sinai, Egypt

The first detailed biostratigraphic analyses of the Coniacian–middle Campanian shallow-marine carbonate successions exposed in the Mitla Pass, west central Sinai, Egypt have revealed the stratigraphic distribution of diverse calcareous nannofossil and planktonic foraminiferal species. Thirty-six calcareous nannofossils and thirty-two planktonic foraminifera are identified, indicating a Coniacian to middle Campanian age and four Tethyan planktonic foraminiferal and five calcareous nannofossil zones. A comparison of these bioevents from different palaeolatitudes shows considerable variation in age. Three sequence boundaries coincident with the Turonian/Coniacian, Coniacian/Santonian and Santonian/Campanian stage boundaries are recognized. A fourth sequence boundary is marked by a major upper Campanian to early Ypresian (early Eocene) unconformity. These sequence boundaries are primarily related to regional tectonism associated with the Syrian Arc Fold System and secondarily to eustatic sea-level fluctuations.

Clonagem do camu-camu arbustivo em porta-enxertos de camu-camu arbustivo e arbóreo

O camu-camu (Myrciaria dubia (H.B.K.) McVaugh), espécie frutífera nativa da Amazônia, de porte arbustivo, é propagado, normalmente, por sementes, ocasionando grande variação na entrada em frutificação e no ciclo de produção, bem como no teor de ácido ascórbico (vitamina C) dos frutos. outra espécie de camu-camu, M. floribunda (West ex Willd.) o. Berg, de porte arbóreo, ocorre em menor densidade na região amazônica. O objetivo deste trabalho foi avaliar a eficiência de diferentes métodos de enxertia e a compatibilidade interespecífica entre camu-camu arbustivo e camu-camu arbóreo na fase de formação de mudas de M. dubia. o ensaio foi desenvolvido no período de março a agosto de 2008, no Instituto Nacional de Pesquisas da Amazônia, em Manaus-AM, com delineamento experimental de blocos ao acaso, em esquema fatorial 4 (métodos de enxertia) x 2 (espécies de porta-enxerto), com quatro repetições. M. dubia, como porta-enxerto, apresentou melhor percentual de pegamento de enxertos (78,4%), comparada a M. floribunda (49,3%). os melhores resultados na clonagem de M. dubia foram obtidos pelos métodos de garfagem, em que a parte aérea do porta-enxerto foi removida após 30 dias da enxertia: fenda lateral (89,3%) e lateral com lingueta (79,3%). o menor resultado foi obtido nos métodos de garfagem, em que a parte aérea do porta-enxerto foi removida na ocasião da enxertia: topo em fenda cheia (51,6%) e inglês complicado (31,5%).

Broad clinical phenotypes associated with TAR-DNA binding protein (TARDBP) mutations in amyotrophic lateral sclerosis

The finding of TDP-43 as a major component of ubiquitinated protein inclusions in amyotrophic lateral sclerosis (ALS) has led to the identification of 30 mutations in the transactive response-DNA binding protein (TARDBP) gene, encoding TDP-43. All but one are in exon 6, which encodes the glycine-rich domain. The aim of this study was to determine the frequency of TARDBP mutations in a large cohort of motor neurone disease patients from Northern England (42 non-superoxide dismutase 1 (SOD1) familial ALS (FALS), nine ALS-frontotemporal dementia, 474 sporadic ALS (SALS), 45 progressive muscular atrophy cases). We identified four mutations, two of which were novel, in two familial (FALS) and two sporadic (SALS) cases, giving a frequency of TARDBP mutations in non-SOD1 FALS of 5% and SALS of 0.4%. Analysis of clinical data identified that patients had typical ALS, with limb or bulbar onset, and showed considerable variation in age of onset and rapidity of disease course. However, all cases had an absence of clinically overt cognitive dysfunction.

Usefulness of Genetic Polymorphisms and Conventional Risk Factors to Predict Coronary Heart Disease in Patients With Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is an autosomal dominant disorder with an associated high risk of coronary heart disease (CHD). The considerable variation in age of onset of CHD in patients with FH is believed to arise from conventional risk factors, as well as genetic variation other than in the low-density lipoprotein receptor gene. The degree to which currently known genetic variants can improve the prediction of CHD risk beyond conventional risk factors in this disorder was investigated. Fourteen genetic variants recently identified for association with CHD in a Dutch FH population were considered. Prediction models were constructed using Cox proportional hazards models, and predictive value was assessed using a concordance statistic (c statistic). A total of 1,337 patients with FH were completely genotyped for all genetic variants. Hazard ratios of the genetic variants ranged from 0.61 to 0.74 and 1.24 to 2.33. The c statistic of the CHD prediction model based on genetic variants was 0.59, denoting little discrimination. The model based on conventional risk factors had a c statistic of 0.75, denoting moderate discrimination. Adding genetic test results to this model increased the c statistic to 0.76. In conclusion, the contribution of 14 genetic variants to the prediction of CHD risk in patients with FH was limited. To improve genome-based prediction of CHD, larger numbers of genetic variants need to be identified that either on their own or in gene-gene interaction have substantial effects on CHD risk.

Small‐scale spatial variation in age and size at maturity of stream‐dwelling brown trout, Salmo trutta

Abstract – This study documents substantial small‐scale spatial variation in age and size at maturity of brown trout (Salmo trutta) found either in allopatry (above major waterfalls) or in sympatry (below waterfalls) with the Alpine bullhead (Cottus poecilopus) in forest streams in south‐east Norway. Within two streams, female brown trout above waterfalls tended to delay the onset of sexual maturity, as compared with females from neighbouring sites below the waterfalls. Four additional streams were represented with either an allopatric or a sympatric site. There was considerable variation in age and size at maturity among these streams, but no consistent difference between allopatric and sympatric sites. It is suggested that the spatial variation in maturity responses is influenced by local opportunities for growth, and possibly also survival. Earlier studies in these streams have linked spatial variation in brown trout behaviour and demography to the presence or absence of the Alpine bullhead.

Obtaining geologically meaningful 40Ar– 39Ar ages from altered biotite

Biotite is the most used 40Ar– 39Ar geochronometer yet two significant problems arise from Ar–Ar step-heating. Dating altered biotite can be problematic, producing disturbed age spectra that reflect 39Ar recoil. However, unaltered biotite can yield disturbed ages with apparently meaningful plateau ages as a result of mineral breakdown during stepped heating. Obtaining meaningful ages from such spectra is very difficult. Because alteration of biotite is common and widespread in nature, and because many biotites affected by alteration are nonetheless unique geologically and/or representative of key localities, the capability to obtain reliable ages from altered material is extremely important. In this study, the effects of alteration progress on biotite age spectra were tested using both IR laser step-heating and UV laser microprobe 40Ar– 39Ar dating techniques. Our aims were to extract geologically meaningful ages from altered biotite and to identify cases where the ages had been influenced by alteration. Three variably altered biotites from the Precambrian metamorphic terrain of southwestern Montana were selected for argon isotopic analysis. Sample A is an unaltered rock containing pristine biotite, sample B is a highly altered rock with chlorite and prehnite interlayers within biotite, and sample C contains biotite with only incipient alteration. For each sample, the biotite ages obtained with IR and UV laser techniques were compared and the validity of the apparent ages was assessed. IR step-heating analysis of biotite from sample A yielded a well-defined plateau of 1776±6 Ma. UV laser microprobe analysis of the same biotite yielded a concordant weighted mean age of 1771±8 Ma, based upon 65 spot analyses of eight grains that ranged in age from 1819±54 to 1722±62 Ma. In contrast, IR step-heating of biotite from sample B resulted in disturbed spectra, with two separate fragments yielding total gas ages of 1505±12 and 1540±16 Ma, whereas UV laser microprobe analysis yielded 14 spot ages ranging from 1806±72 to 1565±78 Ma. UV laser analysis of sample C produced apparent ages ranging from 1772±52 to 1359±200 Ma. Detailed analysis of age variations occurring perpendicular to (001) cleavage planes of biotite in sample B was accomplished by depth profiling using the UV laser microprobe. Depth profiling of single grains revealed considerable age variation among the biotite layers, with profiles 1 and 2 yielding apparent ages ranging from 1730±226 to 1511±186 Ma, and from 1741±290 to 956±230 Ma, respectively. In both samples B and C, younger apparent ages correspond to higher 36Ar/ 39Ar ratios. The youngest ages, therefore, are believed to have derived from altered layers, whereas the oldest ages are related to layers with relatively little or no alteration. In summary, incremental step-heating of altered biotite single grains yields 40Ar– 39Ar age spectra that are compromised by recoil and variable release patterns. However, extraction of small samples via the UV laser microprobe provides a simpler pattern of apparent ages, all younger than the “true” cooling age yet inversely correlated with atmospheric argon. This result suggests that true biotite ages can be recovered from areas of pristine material if they are sufficiently large to be ablated by the UV laser.

Regional variations in deaths from volatile solvent abuse in Great Britain

To assess geographical variations in mortality and the relationship of socio-economic correlates to deaths from volatile substance abuse (VSA) in Great Britain. Analysis of the National Register of deaths from VSA by linking the addresses (postcode) of the deceased to census enumeration districts and hence wards and counties. All 775 deaths in Great Britain listed in the national register between 1985-91. Population counts from the 1991 census were used as denominators. The Poisson heterogeneity test was used to test the null hypothesis that all standardized mortality ratios were from the same population. The t-test was used to compare differences in Townsend Deprivation scores between wards with and without VSA deaths. Multiple regression was used to assess the relationship between indices of deprivation and deaths from VSA. One-third of all VSA deaths occurred in six regions of Great Britain which accounted for 17% of the at risk population. There was considerable variation in age standardized mortality ratios (ASMR) across regions. A ward level analysis indicated that wards with a VSA death had significantly higher levels of deprivation. The Townsend deprivation index showed mean deprivation scores of 2.8 and 0.2, respectively, for wards with and without a registered death (p < 0.0001). Multiple regression at county/region level found that 45% of the variation in ASMR was explained by the components of the Townsend deprivation index. Factors associated with deprivation are important in VSA deaths and this should be taken into account in planning public health measures to prevent mortality.

Body composition of gilts at puberty.

The relationship between body composition and the occurrence of puberty was evaluated using 93 Yorkshire x Landrace gilts. At approximately 60 d of age gilts were purchased and placed in a heated confinement unit where they were housed for the duration of the study. Ad libitum access to feed was provided throughout the study. Gilts were moved, mixed, and initially exposed to mature boars at approximately 120 d of age to encourage the earliest possible occurrence of puberty. Empty body weights of water, fat, protein, and ash at puberty were estimated using a deuterium dilution technique and prediction equations developed for this gilt population. There was considerable variation in age, weight, and all measures of body composition at puberty. Gilts were 138 to 240 d old and weighted 64.9 to 150.8 kg. Backfat thickness ranged from 17.5 to 44.0 mm. Gilts were composed of 32.4 to 64.3 kg of water, 15.6 to 53.9 kg of fat, 9.03 to 20.56 kg of protein, and 1.24 to 3.10 kg of ash. The coefficient of variation for fat to lean ratio at puberty was 15.39%. Linear and quadratic regressions showed that lifetime (birth to puberty) growth rate was not related to age at puberty (P > .10). Based on the variation in body composition observed it was concluded that the occurrence of puberty in gilts given ad libitum access to feed during rearing and initially exposed to mature boars at approximately 120 d of age was not related to certain minimum threshold amounts of body tissues or to a specific rate at which body tissue reserves were accumulated.

Apolipoprotein E polymorphism in a healthy Swedish population: variation of allele frequency with age and relation to serum lipid concentrations

We analyzed blood samples from 407 healthy Swedish individuals, 244 men and 163 women, ages 17 to 86 years, for apolipoprotein (apo) E isoforms and serum triglycerides, low-density lipoprotein (LDL), high-density lipoprotein (HDL), and total cholesterol. Parallel genotyping by means of polymerase chain reaction (PCR)-amplified DNA was performed in 200 subjects. Identical results were obtained by genotyping and phenotyping in 95% of all subjects analyzed. The apo E allelic frequencies were 7.8% for epsilon 2, 71.9% for epsilon 3, and 20.3% for epsilon 4. Compared with other Caucasian populations, the present population had a high relative allelic frequency of epsilon 4. The epsilon 4 frequency decreased with increasing age and was significantly lower in individuals > 60 years of age (14.7%). When controlling for age and sex, there were strong correlations between total serum and LDL cholesterol and the various epsilon alleles. The epsilon 4 and epsilon 3 alleles correlated positively with serum cholesterol and the epsilon 4 allele correlated positively with LDL cholesterol. In contrast, HDL cholesterol and serum triglycerides did not show any correlation to the allele types. Thus, the results demonstrate a considerable age variation of the epsilon allele frequency among healthy Swedes and an influence of apo E alleles on serum and LDL cholesterol concentrations.

40Ar- 39Ar laser probe studies of clinopyroxene inclusions in eclogitic diamonds

40Ar- 39Ar laser probe ages are reported for individual clinopyroxene inclusions in thirty-two eclogitic diamonds from four localities: Jwaneng and Orapa (both in Botswana), Udachnaya (Siberia), and Argyle (Australia). Ages obtained from cleaved diamonds from Jwaneng (244 Ma), Orapa (102 Ma), and Udachnaya (425 Ma) are similar to those of their host kimberlites. However, there is considerable variation in age between individual laser extractions obtained from the same inclusion, which we suspect is mainly due to partial retention of radiogenic argon that diffused to the inclusion/diamond interface while the diamond was in the mantle. Some of this argon was lost when the diamonds were cleaved as part of the experimental procedure. The presence of an ambient mantle 40Ar component trapped in inclusions may be an additional cause of scatter in ages; however, this cannot be validated with the present data. In support of the diffusive loss process, the results from an Udachnaya inclusion completely enclosed within host diamond, with the argon being released by laser drilling, yielded an age of 1149 ± 37 Ma, which is considerably older than the host kimberlite (about 340–400 Ma). Likewise, the scatter in 40Ar K ratios for eclogitic diamonds from Jwaneng and Orapa indicates that they too are probably xenocrysts. Therefore, a combination of sample preparation technique and laser drilling can be used to offer a useful extension of the original method, enabling both diamond formation (from buried inclusions) and host rock emplacement ages (from cleaved inclusions) to be determined. Argyle clinopyroxenes, similarly cleaved to the diamond surface, also show a considerable range of inclusion ages (1159–1540 Ma); only in this case, there is a relationship between age and K Ca ratio of the inclusions. Such a relationship is difficult to reconcile in terms of partial loss of 40Ar and, instead, indicates that there was a protracted period of diamond growth.

Teeth emergence in wild olive baboons in Kenya and formulation of a dental schedule for aging wild baboon populations.

Teeth emergence schedules are presented from analysis of 95 wild olive baboons Papio anubis (age range 2-120 months) and compared to recently published results for wild and captive yellow baboons (P. cynocephalus; Phillips-Conroy and Jolly: American Journal of Primatology 15:17-29, 1988). Age at emergence of M1 (20.5 months males, 19.5 months females), I1 (32.5 and 33.5 months) and I2 (40.0 and 39 months) of olive baboons was earlier than in the wild yellow baboons and similar to captive yellow baboons. However, the later emerging teeth were delayed considerably relative to the captive animals and were similar in age of emergence to those of wild yellow baboons. Considerable variation in age of emergence occurred in the later emerging teeth especially among males. Regression analysis of dental scores with age demonstrated differences between olive baboons and captive yellow baboons but not between olive baboons and wild yellow baboons. Combined data on dental scores for wild yellow, olive, and hamadryas baboons provide schedules of AGE (months) = {SCORE - 11.79} ÷ 0.4405 and AGE (months) = {SCORE - 11.24} ÷ 0.4797 for males and females, respectively, which may be used for aging wild baboons. Full permanent dentition in wild baboons is predicted to occur over 1 year later than in captive animals.

International collaborative study of the spinal muscular atrophies: Part 1. Analysis of clinical and laboratory data

There is considerable variation in age of onset, though in over three-quarters of cases onset is before 4 years of age. A febrile episode, often of viral origin, may be present at the time of onset and might possibly be of aetiological significance, perhaps by precipitating the disease in a genetically predisposed individual. Reduced fetal movements and floppiness at birth are present in about one third of those cases where the onset is in early childhood. It would seem that when the onset is before 4 years of age, and particularly if the child has never been able to sit without support, the prognosis is much worse than in cases where the onset is after the age of 4 years. The proximal limb muscles are predominantly affected and muscle tone is usually reduced but pseudohypertrophy is uncommon. Rarely are the cranial nerves affected. Muscle fasciculations are present in about half the cases. Almost 10% of cases appear to be mentally retarded. With regard to the EMG findings, spontaneous activity, reduced full effort pattern, increased potential amplitude and duration and increased motor unit territory appear to be the most reliable diagnostic criteria. Routine histological evidence of neurogenic atrophy seems to be a more reliable diagnostic criterion than muscle histochemistry. However this may only reflect the way in which the data were selected, that is, from cases where a muscle biopsy showed evidence of neurogenic atrophy on routine histology. Finally the serum level of creatine kinase is rarely very high and in more than half the cases it is normal. The CSF chemistry is always normal.