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The presence of phytoplasmas in Lilium sp. showing severely stunted growth, leaf malformation and flower buds deficiency was demonstrated for the first time using polymerase chain reaction assays with primers amplifying phytoplasma 16S rDNA regions. These phytoplasmas were found in leaves as well as roots and bulb scales of symptomatic and CMV and/or LSV affected and asymptomatic virus-free lilies.  相似文献   
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Nicotiana benthamiana plants were transformed with the movement protein (MP) gene of tobacco mosaic virus (TMV), usingAgrobacterium-mediated transformation. Plants regenerated from the transformed cells accumulated 30-kDa MP and complemented the activity of TMV MP when infected with chimeric TMVs containing defective MR These transgenic plants displayed stunting, pale-green leaves, and starch accumulations, indicating that TMV MP altered the carbon partitioning for leaves involved in TMV cell-to-cell movement.  相似文献   
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Objective: To determine whether African urban children who were stunted at 2 years of age demonstrated an altered body composition by the end of childhood, before entering puberty, at 9 years of age. Research Methods and Procedures: This was a mixed‐longitudinal study of 330 prepubertal African children (182 boys) from Soweto‐Johannesburg, South Africa. Anthropometric data at 2 years of age were compared with anthropometric, DXA‐determined body composition and fat patterning in late childhood (7 to 9 years). Results: Children who had been stunted at 2 years were significantly shorter and lighter than non‐stunted children at 7 to 9 years, but there were no differences in their BMI or centralization of body fat. Previously stunted status significantly predicted reduced weight and height at 7 to 9 years but did not predict BMI, body composition, or fat patterning after controlling for potential confounding factors. The odds ratio for stunting at 2 years as a predictor of overweight at 7 to 9 years was not significant at 1.09 (95% confidence limits: 0.30, 3.98). Discussion: Greater BMI in stunted infants does not demonstrate a tendency toward overweight or obesity but is a reflection of the greater reduction in height rather than weight in stunted children. Stunted children may be programmed to accumulate greater body fat at central sites during adolescence, but we have been unable to show that these changes are evident before the initiation of pubertal development.  相似文献   
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Life history theory integrates ecological, physiological, and molecular layers within an evolutionary framework to understand organisms’ strategies to optimize survival and reproduction. Two life history hypotheses and their implications for child growth, development, and health (illustrated in the South African context) are reviewed here. One hypothesis suggests that there is an energy trade‐off between linear growth and brain growth. Undernutrition in infancy and childhood may trigger adaptive physiological mechanisms prioritizing the brain at the expense of body growth. Another hypothesis is that the period from conception to infancy is a critical window of developmental plasticity of linear growth, the duration of which may vary between and within populations. The transition from infancy to childhood may mark the end of a critical window of opportunity for improving child growth. Both hypotheses emphasize the developmental plasticity of linear growth and the potential determinants of growth variability (including the role of parent–offspring conflict in maternal resources allocation). Implications of these hypotheses in populations with high burdens of undernutrition and infections are discussed. In South Africa, HIV/AIDS during pregnancy (associated with adverse birth outcomes, short duration of breastfeeding, and social consequences) may lead to a shortened window of developmental plasticity of growth. Furthermore, undernutrition and infectious diseases in children living in South Africa, a country undergoing a rapid nutrition transition, may have adverse consequences on individuals’ cognitive abilities and risks of cardio‐metabolic diseases. Studies are needed to identify physiological mechanisms underlying energy allocation between biological functions and their potential impacts on health.  相似文献   
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Artichoke patchy chlorotic stunting (APCS) is the most serious disease affecting artichoke in Greece. It is widespread in Argolis, the main artichoke centre in Greece, where the local thornless artichoke, cv. “Argos”, is cultivated. The disease was first noticed in 1982, but to growers it was known since earlier times. Data collected during 1980–1990 revealed its wide distribution in the area, its patchy dispersal in fields, and its annual radial increase of the patches during the years, as well as a centripetal symptomatological severity gradient within each patch. These observations indicated a soil-borne nature for the disease. Field surveys for several viruses indicated a correlation of APCS with artichoke Italian latent nepovirus (AILV), a soil-borne virus known to occur in such patches and transmitted by the vector nematode Longidorus fasciatus Roca et Lamberti. In experiments fulfilling Koch's postulates, it was possible to reproduce the symptoms of APCS, demonstrating that AILV is a cause of the disease, if not the only one. Field surveys also revealed the ubiquitous occurrence of artichoke mottled crinkle virus (AMCV), independently of any particular symptoms. In the same survey, broad bean wilt virus (BBWV), also, was recovered from artichoke in Greece for the first time.  相似文献   
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1. Benthic invertebrate community composition and yellow perch (Perca flavescens) diet, growth and activity levels from lakes along a metal‐contamination gradient were used to assess the importance of a naturally diverse prey base for maintaining energy transfer to growing fish, and how this transfer is disrupted by metal contamination. 2. Zoobenthic communities had lower diversity in metal‐contaminated lakes, with a notable absence of large bodied invertebrate taxa. 3. The average mass of non‐zooplankton prey items was significantly greater for 2+ and 3+ perch from the reference lake, and increased significantly with age in all except the most contaminated lakes where prey choice was limited. 4. Benthivorous perch from all contaminated lakes exhibited slowed growth. Perch from one of the contaminated lakes exhibited faster growth during piscivory, indicating slowed growth only while benthivorous. 5. Estimates of fish activity, using the activity of the glycolytic enzyme Lactate dehydrogenase in perch white muscle tissue as a proxy, suggested that shifts in diet to larger prey (in reference and intermediately contaminated lakes) lowered activity costs, which may explain how diet shifts maintain growth efficiency as perch grow larger.  相似文献   
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Adult stature variation is commonly attributed to differential stress-levels during development. However, due to selective mortality and heterogeneous frailty, a population's tall stature may be more indicative of high selective pressures than of positive life conditions. This article examines stature in a biocultural context and draws parallels between bioarchaeological and living populations to explore the multidimensionality of stature variation in the past. This study investigates: 1) stature differences between archaeological populations exposed to low or high stress (inferred from skeletal indicators); 2) similarities in growth retardation patterns between archaeological and living groups; and 3) the apportionment of variance in growth outcomes at the regional level in archaeological and living populations. Anatomical stature estimates were examined in relation to skeletal stress indicators (cribra orbitalia, porotic hyperostosis, linear enamel hypoplasia) in two medieval bioarchaeological populations. Stature and biocultural information were gathered for comparative living samples from South America. Results indicate 1) significant (P < 0.01) differences in stature between groups exposed to different levels of skeletal stress; 2) greater prevalence of stunting among living groups, with similar patterns in socially stratified archaeological and modern groups; and 3) a degree of regional variance in growth outcomes consistent with that observed for highly selected traits. The relationship between early stress and growth is confounded by several factors—including catch-up growth, cultural buffering, and social inequality. The interpretations of early life conditions based on the relationship between stress and stature should be advanced with caution. Am J Phys Anthropol 155:229–242, 2014. © 2014 Wiley Periodicals, Inc.  相似文献   
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