Increased rates of illness and death from asthma in Canada.

Recent rates of illness and death from asthma in Canada and rates of hospital admission/separation for asthma were examined by age group and region. The death rates were higher in 1982-84 than in 1970-72, especially among those aged 15 to 34 years. Increases were also noted in hospital admission/separation rates, especially among those less than 15 years of age. Hospital admission/separation rates were highest in the Maritime provinces and Saskatchewan, whereas death rates were highest in Alberta and Saskatchewan. Examination of death certificates for coding errors and recoding of certificates to a single (8th) revision of the International Classification of Diseases indicated that changes in disease coding and errors in coding did not account for the significant increase in rates of death from asthma for those aged 15 to 34 years. These increases in rates of illness and death from asthma are unexplained and warrant further investigation.     

The positive rates of hepatitis B surface antibody in youth after booster vaccination: a 4-year follow-up study with large sample

Background: Hepatitis B virus (HBV) infection is still a public issue in the world. Hepatitis B vaccination is widely used as an effective measure to prevent HBV infection. This large-sample study aimed to evaluate the positive rates of hepatitis B surface antibody (anti-HBs) in youth after booster vaccination.Methods: A total of 37788 participants were divided into two groups according to the baseline levels of anti-HBs before booster vaccination: the negative group (anti-HBs(−)) and the positive group (anti-HBs(+)). Participants were tested for anti-HBs levels after receiving a booster vaccine at 1 and 4 years.Results: The positive rates of anti-HBs were 34.50%, 73.80% and 67.32% before booster vaccination at 1 and 4 years after vaccination, respectively. At 4 years after the booster vaccination, the positive rates of 13–18 years were 47.54%, which was the lowest level among all youth age groups. In the anti-HBs(−) group, the positive conversion rates of anti-HBs were 74.62% at 1 year after receiving a booster vaccine, and 67.66% at 4 years after vaccination. In the anti-HBs(+) group, the positive maintenance rates of anti-HBs were 70.16% after 1 year, and 66.66% after 4 years. Compared with the baseline anti-HBs (+) group, the positive rates of the baseline anti-HBs(−) group were higher at 1 and 4 years after receiving the booster vaccine.Conclusion: The positive rates of anti-HBs declined over time, especially the positive maintenance rates were the lowest at age of 13–18 years.     

Evolutionary patterns in early tetrapods. I. Rapid initial diversification followed by decrease in rates of character change

Although numerous studies have examined morphological diversification during major radiations of marine taxa, much less attention has been paid to terrestrial radiations. Here, we examine rates of character change over phylogeny and over time for Palaeozoic limbed tetrapods. Palaeozoic tetrapods show significant decreases in rates of character change whether the rate is measured per sampled cladistic branch or per million years along phylogeny. Given changes per branch, rates decrease significantly from the Devonian through the Pennsylvanian, but not from the Pennsylvanian through the Permian. Given changes per million years, rates decrease significantly over each boundary, although the decrease is least significant over the Pennsylvanian-Permian boundary. Decreasing rates per million years through the Permian might be an artefact of the method being able to ascribe longer durations to Permian branches than to Carboniferous ones; however, it is difficult to ascribe the general pattern of decreasing rates of change over time to sampling biases or methodological biases. Thus, the results implicate biological explanations for this pattern.     

The effect of age and year on the survival of breeding adult Great Skuas Catharacta skua in Shetland

The survival rates of breeding adult Great Skuas Catharacta skua were examined at Foula, the largest colony in the world, where numbers have been declining since the late 1970s. Resightings of colour-ringed breeding adults over a 12-year period were analysed using Cormack-Jolly Seber models to estimate survival rates. Annual survival rates averaged 0.89 but varied among years between 0.82 and 0.93, with annual variations being temporally associated with variations in sandeel abundance during the breeding season. Most birds appeared to die outside the breeding season and so it is possible that nutritional stress and reproductive costs of breeding in years of poor food supply affect survivorship on migration or in the wintering range. Survival rates of adult Great Skuas were affected by their age according to a quadratic equation, with survival increasing significantly with age from 0.73 in 5-year-old-birds to between 0.85 and 0.96 in birds from 7 to 22 years old, with a sharp decline to between 0.75 and 0.87 in birds over 22 years old. Year effects were evident when controlling for age, indicating that annual variations in survival rates are not explained by changes in age-composition of the marked population among years.     

Survival Rates of Female Greater Sage-Grouse in Autumn and Winter in Southeastern Oregon

ABSTRACT We estimated survival rates of 135 female greater sage-grouse (Centrocercus urophasianus) on 3 study areas in southeastern Oregon, USA during autumn and winter for 3 years. We used known-fate models in Program MARK to test for differences among study areas and years, investigate the potential influence of weather, and compute estimates of overwinter survival. We found no evidence for differences in survival rates among study areas, which was contrary to our original hypothesis. There also were no declines in survival rates during fall-winter, but survival rates varied among years and time within years. Average survival rate from October through February was 0.456 (SE = 0.062). The coefficient of variation for this estimate was 13.6% indicating good precision in our estimates of survival. We found strong evidence for an effect of weather (i.e., mean daily min. temp, extreme min. temp, snow depth) on bi-weekly survival rates of sage-grouse for 2 of the study areas in one year. Extremely low (<-15°C) temperatures over an 8-week period and accumulation of snow had a negative effect on survival rates during the winter of 1990–1991 on the 2 study areas at the higher (>1,500 m) elevations. In contrast, we found no evidence for an influence of weather on the low-elevation study area or during the winters of 1989–1990 and 1991–1992. Extreme weather during winter can cause lower survival of adult female sage-grouse, so managers should be aware of these potential effects and reduce harvest rates accordingly.     

献血员巨细胞病毒感染的研究

用ＰＣＲ法和ＤＮＡ杂交法检测同一献血员的白细胞及血清中的ＨＣＭＶ－ＤＮＡ,并用ＥＬＩＳＡ法检测血清中的ＨＣＭＶ－ＩｇＭ、ＩｇＧ（测四个不度）,连续两年共检测白细胞和血清样本各２００人份。ＰＣＲ法检测白细胞中的ＨＣＭＶ－ＤＮＡ阳性率分别为６３％和７０％,ＤＮＡ杂交法检测的阳性率为４２％和５０％。ＰＣＲ法检测血清中的ＨＣＭＶ－ＤＮＡ的阳性率为４９％和５３％,ＤＮＡ杂交法检测的阳性率为３３％和３９％。Ｈ     

青海省2006年14岁以下儿童百日咳白喉破伤风抗体水平监测

调查青海省0~14岁健康儿童百日咳、白喉、破伤风抗体水平,抽样评价预防接种质量。在全省六州一地一市各选择1个县,对0~14岁健康儿童进行抗体检测。结果显示,百日咳、白喉、破伤风抗体阳性率分别为93.42%、94.96%和92.93%。不同地区0~14岁健康儿童百日咳、白喉和破伤风抗体阳性率虽有差别,但都达到较高的抗体水平;个别地区抗体水平低,说明青海省儿童计划免疫工作存在薄弱环节。     

Carcinoma of the Lung: The Changing Pattern of Mortality in Ontario

Study of the mortality rates for carcinoma of the lung in men in Ontario between 1931 and 1959 reveals a rise from 3.7 in the early 1930''s to 26.7 per 100,000 in the late 1950''s. Analysis of age-specific mortality rates in five-year cohorts (groups of men born within five-year periods) shows that (1) mortality rates in each cohort rise rapidly after the age of 40, ascending in the later years of life almost as a straight line; (2) each succeeding cohort experiences an appreciably higher mortality rate than the preceding one. Mortality rates in individual cohorts in Ontario are compared with those in England; the shape of the cohort curves, and the rate of the increase in mortality from cohort to cohort, are almost identical. However, the picture in Ontario appears to be lagging some 10 years behind. The mortality rates for men in Ontario born around the year 1890 are almost identical with those shown by men born in England around 1880. The rates for carcinoma of the lung will almost inevitably continue to rise in Ontario for at least the next 10 to 20 years.     

Long-term trends in survival of a declining population: the case of the little owl (<Emphasis Type="Italic">Athene noctua</Emphasis>) in the Netherlands

The little owl (Athene noctua) has declined significantly in many parts of Europe, including the Netherlands. To understand the demographic mechanisms underlying their decline, we analysed all available Dutch little owl ringing data. The data set spanned 35 years, and included more than 24,000 ringed owls, allowing detailed estimation of survival rates through multi-state capture–recapture modelling taking dispersal into account. We investigated geographical and temporal variation in age-specific survival rates and linked annual survival estimates to population growth rate in corresponding years, as well as to environmental covariates. The best model for estimating survival assumed time effects on both juvenile and adult survival rates, with average annual survival estimated at 0.258 (SE = 0.047) and 0.753 (SE = 0.019), respectively. Juvenile survival rates decreased with time whereas adult survival rates fluctuated regularly among years, low survival occurring about every 4 years. Years when the population declined were associated with low juvenile survival. More than 60% of the variation in juvenile survival was explained by the increase in road traffic intensity or in average temperature in spring, but these correlations rather reflect a gradual decrease in juvenile survival coinciding with long-term global change than direct causal effects. Surprisingly, vole dynamics did not explain the cyclic dynamics of adult survival rate. Instead, dry and cold years led to low adult survival rates. Low juvenile survival rates, that limit recruitment of first-year breeders, and the regular occurrence of years with poor adult survival, were the most important determinants of the population decline of the little owl.     

High cancer mortality rates in the elderly in the UK

Introduction: Cancer is largely a disease of older individuals. We compared UK cancer mortality rates with those for other countries to assess progress. Methods: Death details were obtained from the WHO Mortality Database for the UK, the USA and 11 European countries. Mortality rates were calculated for the age groups 55–64, 65–74, 75–84 and ≥85 years. Trends between 1995–97 and 2003–05 were determined. The number of excess cancer deaths in the UK was calculated by applying the age-specific mortality rates observed in other regions to the UK. Results: For all cancers combined, UK rates for 2003–05 in those aged ≥75 years were 11–31% higher than in other regions. From 1995–97 to 2003–05, UK rates decreased by 16–17% in those aged <75 years, but increased by 2% in those ≥85 years compared with decreases of 4–16% for the other geographic areas. More than 14,000 cancer deaths in the UK in those aged ≥75 years would be avoided each year if UK mortality rates were identical to those in the USA. Conclusion: The UK is making poor progress in controlling cancer in older age groups. The gap in mortality rates between the UK and other countries and between old and young in the UK is widening.     

Age-related survival in female Sparrowhawks Accipiter nisus

Long-term capture-recapture of female Sparrowhawks Accipiter nisus nesting in three different areas enabled age-related survival rates to be calculated, after correcting for age-related and annual variations in recapture frequency. The data provided strong evidence for an improvement in survival rates in the first 3 years of life and for a decline in the last 5–6 years, during a maximum life span of around 10 years. The decline in survival among older birds was attributed to senescence. At all ages, survival rates were higher in the English area, where breeding numbers were rapidly increasing, than in two Scottish areas, where breeding numbers were stable or declining. The precise pattern of change in survival rates with age may vary between areas, according to prevailing circumstances.     

Decline in rate of death from ischaemic heart disease in the United Kingdom.

The rates of death from ischaemic heart disease in the United Kingdom in the years after 1968 were studied to establish whether any general trend had occurred. A decline in the rates began after 1973-4, was greatest in those aged 35-44 years, and occurred among both men and women and in each of the regions of England and in Wales and Scotland. Total dietary fat intake had started to fall about five years earlier, and this may provide part of the explanation. Changes in smoking habits also occurred but were more difficult to relate to the pattern of change in the death rates. If a general decline in ischaemic heart disease has begun in the United Kingdom a case may be made for close monitoring of changes in lifestyle and medical practice in different demographic groups to try to find the explanation.     

Causes of Early Childhood Deaths in Urban Dhaka,Bangladesh

Data on causes of early childhood death from low-income urban areas are limited. The nationally representative Bangladesh Demographic and Health Survey 2007 estimates 65 children died per 1,000 live births. We investigated rates and causes of under-five deaths in an urban community near two large pediatric hospitals in Dhaka, Bangladesh and evaluated the impact of different recall periods. We conducted a survey in 2006 for 6971 households and a follow up survey in 2007 among eligible remaining households or replacement households. The initial survey collected information for all children under five years old who died in the previous year; the follow up survey on child deaths in the preceding five years. We compared mortality rates based on 1-year recall to the 4 years preceding the most recent 1 year. The initial survey identified 58 deaths among children <5 years in the preceding year. The follow up survey identified a mean 53 deaths per year in the preceding five years (SD±7.3). Under-five mortality rate was 34 and neonatal mortality was 15 per thousand live births during 2006–2007. The leading cause of under-five death was respiratory infections (22%). The mortality rates among children under 4 years old for the two time periods (most recent 1-year recall and the 4 years preceding the most recent 1 year) were similar (36 versus 32). The child mortality in urban Dhaka was substantially lower than the national rate. Mortality rates were not affected by recall periods between 1 and 5 years.     

Temporal and spatial variation in age-specific survival rates of a long-lived mammal, the Hawaiian monk seal

Estimates of variability in pinniped survival rates are generally based on observations at single sites, so it is not certain whether observed rates represent the whole population. Here, we provide a comprehensive analysis of spatio-temporal variation in age-specific survival rates for endangered Hawaiian monk seals (Monachus schauinslandi) based on capture-recapture analyses of more than 85% of the pups weaned in this population over the last two decades. Uniquely, these data have been collected from six subpopulations, encompassing all major breeding sites across its 1800 km long core range. Analyses of individual subpopulations revealed similar patterns in age-specific survival, characterized by the relatively low survival rates from weaning to 2 years of age, intermediate rates to 4 years of age, and then by relatively high 'mature' survival rates until 17 years of age, after which a senescent decline was observed. Juvenile, subadult and adult survival rates all varied significantly over time. Trends in survival among subpopulations were coherent with their relative geographical positions, suggesting regional structuring and connectedness within the archipelago. Survival rates for different age classes tended to be positively correlated, suggesting that similar factors may influence the survival for seals of all ages.     

深圳市龙岗区流感监测及健康人群流感抗体水平分析

对深圳市龙岗区近几年流感病原学及人群流感抗体水平的分析,为流感防控提供科学依据。通过流感监测系统对流感进行病原学和血清学监测的结果显示,2007年流感病毒分离率为1.08%(3/277),2009年分离率为6.68%(56/838),两年流感病毒分离率差别具有统计学意义(χ2=13.03,P=0.000)。2007年健康人群血清样本中H1N1、H3N2、BY、BV流感抗体阳性率分别为60.5%、82.1%、59.3%、50.2%,2010年健康人群血清样本中H1N1、H3N2、BY、BV、甲型H1N1流感抗体阳性率分别为36.2%、37.6%、40.2%、21.9%、37.6%,2007年和2009年各亚型流感抗体阳性率具有统计学意义(P<0.05),两年中均表现H3N2亚型抗体阳性率最高,BV抗体阳性率最低。2007年和2010年H1N1、H3N2、BY、BV抗体阳性率均高于2010年,差别均具有统计学意义(P<0.01)。因此应加强流感病毒抗原变异株和人群流感水平的监测,对5岁以下及20岁以上的易感人群加强流感疫苗的接种,预防流感大流行。     

Molecular versus Taxonomic Rates of Evolution in Planktonic Foraminifera

Neogene planktonic foraminifera are among the most widely used microfossils in the study of tempo and mode of evolution. Comparisons of taxonomic rates between the two major clades in this group have shown that the nonspinose globorotaliids have undergone a significantly more rapid evolutionary turnover than the spinose globigerinids (S. M. Stanleyet al., 1988,Paleobiology14, 235–249). In order to test if similar fluctuations are observed in molecular data, we have used different methods to calculate absolute and relative rates of substitutions based on 16 partial SSU rDNA sequences from representatives of both groups. According to our data, rates of substitution are relatively constant within the globigerinids with a mean value of 4.3 subst./site/10⁹years, but vary in the globorotaliid clade with three species having a rate of about 1 subst./site/10⁹years and two species evolving much faster with rates of more than 7 subst./site/10⁹years. Assuming that the fast rates result from recent accelerations, the globorotaliids have basically much slower molecular evolutionary rates than the globigerinids, in opposition to the fossil data.     

Secular trend in the stature and weight of Mexican-American children in Texas between 1930 and 1970

Statures and weights for four samples of Mexican-American children in Texas, measured in 1929–1931 and 1968–1972, were evaluated for evidence of a secular trend. The age range was 6 to 18 years, with more complete data from 8 through 15 years. There is no secular increase in the statures and weights of 6 year old children, a small increase in 8 years old children, and a larger secular increase at 10, 12, 14, and 15 years of age. From about 9 or 10 years of age on, the more recent Mexican-American children tend to have greater weights for their heights. The magnitudé of the secular change per decade, however, is considerably smaller than rates for US black, white, European, and Japanese children. The estimated rates of secular change in stature for Mexican-American children approximate about one-fourth to one-half of the generalized rates for European and North American children offered by Meredith ('76) and Tanner ('77). Reasons for a limited secular trend in Texas Mexican-American children are probably bound to the matrix of lower socioeconomic circumstances, poorer health conditions, and marginal nutritional status.     

Detrital processing in streams exposed to acidic precipitation in the Central Appalachian Mountains

Continuing high rates of acidic deposition in the eastern United States may lead to long-term effects on stream communities, because sensitive catchments are continuing to lose anions and cations. We conducted a two-year study of the effects of pH and associated water chemistry variables on detrital processing in three streams with different bedrock geology in the Monongahela National Forest, West Virginia. We compared leaf pack processing rates and macroinvertebrate colonization and microbial biomass (ATP concentration) on the packs in the three streams. Breakdown rates of red maple and white oak leaf packs were significantly lower in the most acidic stream. The acidic stream also had significantly lower microbial and shredder biomass than two more circumneutral streams. Shredder composition differed among streams; large-particle detritivores dominated the shredder assemblages of the two circumneutral streams, and smaller shredders dominated in the acidic stream. Within streams, processing rates for three leaf species were not significantly different between the two years of the study even though invertebrate and microbial communities were different in the two years. Thus, macroinvertebrate and microbial communities differed both among streams that differed in their capacity to buffer the effects of acidic precipitation and among years in the same stream; these differences in biotic communities were not large enough to affect rates of leaf processing between the two years of the study, but they did significantly affect processing rates between acidic and circumneutral streams.The Unit is jointly sponsored by the National Biological Service, the West Virginian Division of Natural Resources, West Virginia University, and the Wildlife Management Institute.The Unit is jointly sponsored by the National Biological Service, the West Virginian Division of Natural Resources, West Virginia University, and the Wildlife Management Institute.     

Twinning rates in a rural area of Bangladesh

In this study we investigate the incidence of twin births over a period of 16 years in a rural area of Bangladesh using data from the Demographic Surveillance System of the International Centre for Diarrhoeal Disease Research. Over the study period twinning rates fluctuated between 7.8 and 11.2 per 1000 live births. The twinning rate was strongly correlated with maternal age; the rate for mothers over 35 years of age was about 3 times higher than for mothers younger than 20 years. The variation in twinning rate with maternal age is due to the variation in dizygotic twinning; the rate of monozygotic twinning is almost constant for all ages. Twinning rates were higher in the treatment area than in the comparison area after controlling for maternal age and parity. The rates were lower for monozygotic twinning and higher for dizygotic twinning in the treatment area than in the comparison area. Seasonality was observed for both twins and singletons, but the peak for twinning precedes that for singleton births by more than a month.     

Ward Design in Relation to Postoperative Wound Infection: Part III

The wound infection rates, nasal carriage rates, and nasal colonization rates were studied in a recently built surgical unit for two years when it was first opened. Five years later a further two-year period of study was undertaken.Judging by the incidence of postoperative wound infection, as far as both Staphylococcus pyogenes and Gram-negative organisms are concerned, there is no evidence that the environment has become less safe with use over the seven-year period since opening.