Preimplantation Stress and Development

The developmental origins of health and disease hypothesis holds that inappropriate environmental cues in utero, a period marked by tremendous developmental sensitivity, facilitate cellular reprogramming to ultimately predispose disease in adulthood. In this review, we analyze if stress during early stages of development can affect future health. This has wide clinical importance, given that 5 million children have been conceived with assisted reproductive technologies (ART). Because the primary outcome of assisted reproduction procedures is delivery at term of a live, healthy baby, the postnatal effects occurring outside ofthe neonatal period are often overlooked. To this end, the long‐term outcome of ART is appropriately the most relevant concern of the field today. Evidence of adverse consequences is controversial. The majority of studies have concluded no obvious problems in IVF‐conceived children, although a number of isolated cases of imprinted diseases, cancers, or malformations have been reported. Given that animal studies suggest alteration of metabolic pathways following preimplantation stress, it will be of great importance to follow‐up ART individuals as they enter later stages of adult life. Birth Defects Research (Part C) 96:299–314, 2012. © 2013 Wiley Periodicals, Inc.     

离体植物花芽和花器官的发育研究进展

在近二十几年,尤其是近十年由于离体培养技术的完善和进一步向精确的层次的发展,已使得许多种植物花序、花芽和单独花器官以及部分的花器官在体外成功地进行了培养和尝试,并且对花芽及花器官的离体发育有了更深入的认识。不同植物的花发育需要不同的植物生长调节剂以及它们的不同配比,并且不同植物在其花发育所需要的营养因子也存在着相当大的差异性。这种差异性又随植物器官及花发育的不同阶段而受到加大或缩小。通过对正常花及突变体花进行的离体培养实验研究已经对一些花器官发生过程中的调节程序有了新的了解。利用离体培养技术,包括刚发展起来的薄层细胞培养技术在阐明花发育的机理、形态建成的分子机制以及成花梯度的物质基础等问题上具有广阔的潜力。     

Cinefluorography of the Urinary Tract in Children

Most of the recent investigations of the lower urinary tract have been concentrated on the ureterovesical junction. Studies of 120 children examined by the method of voiding cinecystography and urethrography revealed that vesicoureteral reflux occurred in 22 cases without evidence of a lesion of the urethra, and in six children secondary to lesions of the urethra. Thirteen of the children studied had isolated lesions of the urethra. Urethral lesions encountered in this series of children included stenosis of the external meatus (14 cases), urethral valve (one case), urethral polyp (one case) and urethral stricture (two cases). The main advantages of cinefluorography and television control in this field lie in the fact that all phases of the voiding act can be observed and, when necessary, recorded on a movie film. Motion picture films provide visual evidence of the value of the method.     

A comparison of four methods for measuring roots of field crops in three contrasting soils

Rooting measurements have been made at different growth stages for sugar beets (1987) and for cereals (1988) on three different sites using four different root measurement techniques: (a) the core method where roots were extracted and root length is directly measured, (b) the core-break method where the visible roots were counted on the faces of a broken soil column, (c) the trench profile wall method where the number of visible roots were counted and the root length density was estimated on a profile wall, and (d) the monolith method where the roots were extracted from monoliths dug out from a profile wall. The calibration curves between the field methods and the extraction methods were not linear, and regression coefficients differed significantly between different sites, crops and between fields with different agronomic management, e.g. irrigation and liquid manure application. Differences between growth stages were comparably low compared with those found between locations. Root length densities obtained with the trench profile method were on average 10-fold lower in the sand brown earth, 6-fold lower in the vertisol and 4 times lower in the cambisol compared to data obtained with the core method. It is therefore concluded that the core-break method and the trench profile wall method deliver no reliable data for comparing rooting intensities between different soils and between different crops if they are not calibrated with an extraction method for each site and crop.     

The mineral composition of the Robusta banana plant

Summary The problem of the nutrition of the banana plant and the limitations of traditional field fertilizer trials are described. Complementary studies of total uptake are valuable and have been carried out at various sites in the Eastern Caribbean. In this paper, dry-matter production at different stages of growth of Robusta bananas is presented. Differences in pattern are related to site factors. Distribution and redistribution of dry matter amongst the various plant organs are given for the different stages of growth. Calculations of fresh and dry matter for a field production of 25 and 50 tonnes per ha have been made. re]19720703     

A comparison of the metamorphosing and macrophthalmia stages of the lampreys Lampetra fluviatilis and L. planeri

Comparisons of metamorphosing and macrophthalmia stages of the closely related species, L. fluviatilis (L.) and L. Planeri (Bloch), have shown that these can be distinguished within a few weeks of the onset of metamorphosis by characteristic differences in colouration and body form. Measurements of several body intervals have disclosed differences between the macrophthalmia stages of the two species. A sharp distinction between the blunt teeth of L. planeri and the supposedly sharp teeth of L. fluviatilis has not been confirmed in these early stages, but significant differences have been found in the numbers of teeth in the anterior field of the oral disk and in the lateral and posterior marginal series. For material from several rivers, the range of length of metamorphosing and macrophthalmia stages of L. fluviatilis is83–119 mm (mean 99.3 mm). Weights varied from 0.71-2.5 g (mean 1.51 g). Regression coefficients for weight on length are much lower in the macrophthalmia of L. fluviatilis than in comparable stages of L. planeri. Total oocyte counts on macrophthalmia of L. fluviatilis gave values from8000–20,000 which are in general agreement with egg counts for adults of this species in the river Severn. Observations on the earliest metamorphosing forms have shown that it is not possible at this stage to distinguish the males of the two species by the structure of the testes. The development of the lumen in the adult foregut of L. fluviatilis has been shown to be variable and in some instances the gut does not become patent until early Spring. The possibility has also been raised that, in exceptional cases, a temporary lumen may also be present for a short period in L. planeri. Observations on the foregut and dentition, together with field data, suggest that the climax of downstream migration and the onset of parastic feeding takes place in late March or April.     

Patterns of Development of Intellectual Functions in Deaf Children 7-12 Years Old

Study of the developmental characteristics of higher mental functions in congenitally deaf children who otherwise have no primary mental defects should help us improve differential diagnosis of abnormal mental development in children with this sensory defect and further differentiate remedial, medical, and pedagogical measures that take into account the specifics of both the sensory defect and the cerebral anomaly. Much has been achieved in study of the distinctive features of cognitive development in deaf children, thanks to the efforts of Zh.I. Shif, T.V. Rozanova, N.V. Iakovleva, A.P. Gozova, and N.V. Iashkova [8,9]. Nevertheless, some aspects of the development of intellectual functions in the deaf and, in particular, the nature of the interrelations among the different mental functions in the process of individual development, have not been sufficiently studied at the different ontogenetic stages in children with this sensory impairment.     

Time-conditioned coordination of dehydrogenase activity in blood cells in infantile acute leukemia.

The correlation of enzymatic activities studied at different periods of time (lasting from several hours to several days) has been revealed in 39 children at different stages of acute leukemia and in 8 children suffering from other hematological diseases (Hodgkin's disease, Morbus Werlhof, reactive reticulosis). The correlation of activity of enzymes constituting different systems and arranged in different parts of cell organelles enables us to explain this phenomenon by a regulation on a higher level, viz. cytophysiological processes as a whole. The coordination of enzymes possible depends on the synchronism of enzymatic activity caused by the physiological process developing in the cell.     

Exposure of children to residential magnetic fields in Norway: Is proximity to power lines an adequate predictor of exposure?

The aim of this work was to study the exposure to magnetic fields of children living at different distances from a power line and to evaluate how well theoretical calculations compared with actual exposure. Personal exposure instruments were carried for 24 h by 65 schoolchildren living 28–325 m from a 300 kV transmission line; the current load was 200–700 A. About half of the children attended a school far from the power line, whereas the other half attended a school located about 25 m from the line. Exposure to magnetic fields was analyzed for three categories of location: at home, at school, and at all other places. Time spent in bed was analyzed separately. The results indicated that children who lived close to a power line had a higher magnetic field exposure than other children. The power line was the most important source of exposure when the magnetic field due to the line was greater than about 0.2 μT. Exposure at school influenced the 24 h time-weighted average results considerably in those cases where the distance between home and power line was very different from the distance between school and power line. The calculated magnetic field, based on line configuration, current load, and distance between home and power line, corresponded reasonably well with the measured field. However, the correlation depends on whether home only or 24 h exposure is used in the analysis and on which school the children attended. The calculated magnetic field seems to be a reasonably good predictor of actual exposure and could be used in epidemiological studies, at least in Norway, where the electrical system normally results in less ground current than in most other countries. Bioelectromagnetics 18:47–57, 1997. © 1997 Wiley-Liss, Inc.     

Diversity,specificity and impacts on field epidemics of QTLs involved in components of quantitative resistance in the wheat leaf rust pathosystem

Quantitative resistance is generally associated with several genes, located in quantitative trait loci (QTLs). Although often described as non-isolate-specific and durable, some cases of erosion of this resistance have been observed. The likelihood of an erosion of quantitative resistance could be reduced, provided that this resistance rests on diversified mechanisms. We hypothesized that QTLs phenotypically expressed on different components, govern different mechanisms of resistance. A doubled haploid population of 91 lines, derived from a cross between the wheat cultivars Apache and Balance, was used to identify leaf rust resistance QTLs. After establishing a linkage map with 355 markers, 13 QTLs were found involved in field resistance, for over 2 years in two locations. Ten of these QTLs were associated with five resistance components (infection efficiency, latent period, lesion size, spore production per lesion and spore production per unit of sporulating tissue) measured in two greenhouse experiments. All but one of the QTLs found in the greenhouse were associated with one or two resistance components, supporting the hypothesis that different genetic factors are mostly involved in the expression of different resistance components. Analyzing separately different field scoring dates revealed QTLs involved at different stages of the epidemic. The QTLs displayed different degrees of isolate-specificity on field resistance, as measured by LOD scores and R ², leading to the conclusion that isolate-specificity is both a qualitative and quantitative feature of quantitative resistance. A profile of each QTL was drawn, to evaluate its usefulness according to the objectives of the breeding program.     

Upper arm circumference development in Chinese children and adolescents: a pooled analysis

Background

Upper arm development in children is different in different ethnic groups. There have been few reports on upper arm circumference (UAC) at different stages of development in children and adolescents in China. The purpose of this study was to provide a reference for growth with weighted assessment of the overall level of development.

Methods

Using a pooled analysis, an authoritative journal database search and reports of UAC, we created a new database on developmental measures in children. In conducting a weighted analysis, we compared reference values for 0~60 months of development according to the World Health Organization (WHO) statistics considering gender and nationality and used Z values as interval values for the second sampling to obtain an exponential smooth curve to analyze the mean, standard deviation, and sites of attachment.

Results

Ten articles were included in the pooled analysis, and these articles included participants from different areas of China. The point of intersection with the WHO curve was 3.5 years with higher values at earlier ages and lower values at older ages. Boys curve was steeper after puberty. The curves in the studies had a merged line compatible. The Z values of exponential smoothing showed the curves were similar for body weight and had a right normal distribution.

Conclusions

The integrated index of UAC in Chinese children and adolescents indicated slightly variations with regions. Exponential curve smoothing was suitable for assessment at different developmental stages.     

Age estimation from the auricular surface of the ilium: a revised method

A revised method for estimating adult age at death using the auricular surface of the ilium has been developed. It is based on the existing auricular surface aging method of Lovejoy et al. ([1985] Am. J. Phys. Anthropol. 68:15-28), but the revised technique is easier to apply, and has low levels of inter- and intraobserver error. The new method records age-related stages for different features of the auricular surface, which are then combined to provide a composite score from which an estimate of age at death is obtained. Blind tests of the method were carried out on a known-age skeletal collection from Christ Church, Spitalfields, London. These tests showed that the dispersion of age at death for a given morphological stage was large, particularly after the first decade of adult life. Statistical analysis showed that the age-related changes in auricular surface are not significantly different for males and females. The scores from the revised method have a slightly higher correlation with age than do the Suchey-Brooks pubic symphysis stages. Considering the higher survival rates of the auricular surface compared with the pubic symphysis, this method promises to be useful for biological anthropology and forensic science.     

A Novel Technique for Identifying the Instar of Field-Collected Insect Larvae

Many field studies of insects have focused on the adult stage alone, likely because immature stages are unknown in most insect species. Molecular species identification (e.g., DNA barcoding) has helped ascertain the immature stages of many insects, but larval developmental stages (instars) cannot be identified. The identification of the growth stages of collected individuals is indispensable from both ecological and taxonomic perspectives. Using a larval–adult body size relationship across species, I present a novel technique for identifying the instar of field-collected insect larvae that are identified by molecular species identification technique. This method is based on the assumption that classification functions derived from discriminant analyses, performed with larval instar as a response variable and adult and larval body sizes as explanatory variables, can be used to determine the instar of a given larval specimen that was not included in the original data set, even at the species level. This size relationship has been demonstrated in larval instars for many insects (Dyar’s rule), but no attempt has been made to include the adult stage. Analysis of a test data set derived from the beetle family Carabidae (Coleoptera) showed that classification functions obtained from data sets derived from related species had a correct classification rate of 81–100%. Given that no reliable method has been established to identify the instar of field-collected insect larvae, these values may have sufficient accuracy as an analytical method for field-collected samples. The chief advantage of this technique is that the instar can be identified even when only one specimen is available per species if classification functions are determined for groups to which the focal species belongs. Similar classification functions should be created for other insect groups. By using those functions together with molecular species identification, future studies could include larval stages as well as adults.     

Compositional profiling of heparin/heparan sulfate using mass spectrometry: assay for specificity of a novel extracellular human endosulfatase

An important class of carbohydrates studied within the field of glycobiology, heparin and heparan sulfate (HS) have been implicated in a diverse array of biological functions. Changes in their sulfation pattern and domain organization have been associated with different pathological situations such as viral infectivity, tumor growth, and metastasis. To obtain structural information about these biomolecules, and the modifications they may undergo during different stages of cell growth and development, a mass spectrometry-based method was developed and used to obtain unambiguous structural information on the glycosaminoglycans (GAGs) that comprise heparin/HS. The method was applied to assay for the heparin substrate specificity of a newly discovered human extracellular endosulfatase, HSulf-2, which has been implicated in tumorigenesis. This new protocol incorporates 12 known heparin disaccharides, including three sets of isomers. A unique response factor (R) is determined for each disaccharide, whereas a multiplexed and data processing method is incorporated for faster data acquisition and quantification purposes. Proof of principle was performed by using various heparin/HS samples isolated from bovine and porcine tissues.     

Investigation of pulsed electromagnetic field as a novel organic pre-sowing method on germination and initial growth stages of cotton

Two different pre-sowing techniques have been investigated for their influence in an important industrial plant, namely cotton. Priming methods are very useful for agricultural practices because they improve crop seedling establishment, especially when environmental conditions are not optimum. Pulsed electromagnetic fields have been found to promote germination and improve early growth characteristics of cotton seedlings. Such priming techniques are especially valuable in organic cultivation, where chemical compounds are prohibited. PEG treatment showed an enhancement in some measurements, however in some cases the results were not statistically different compared to control plants. In addition, PEG treatment is a sophisticated method that is far from agricultural practices and farmers. In this research, two different ages of seeds were used (1- and 2-year-old) in order to investigate the promotory effects of priming techniques. Magnetic field treatment of 15 min was found to stimulate germination percentage and to promote seeds, resulting in 85% higher values than control seeds under real field conditions. Furthermore, seeds that were treated with magnetic field performed better in terms of early-stage measurements and root characteristics.     

Investigation of pulsed electromagnetic field as a novel organic pre-sowing method on germination and initial growth stages of cotton

Two different pre-sowing techniques have been investigated for their influence in an important industrial plant, namely cotton. Priming methods are very useful for agricultural practices because they improve crop seedling establishment, especially when environmental conditions are not optimum. Pulsed electromagnetic fields have been found to promote germination and improve early growth characteristics of cotton seedlings. Such priming techniques are especially valuable in organic cultivation, where chemical compounds are prohibited. PEG treatment showed an enhancement in some measurements, however in some cases the results were not statistically different compared to control plants. In addition, PEG treatment is a sophisticated method that is far from agricultural practices and farmers. In this research, two different ages of seeds were used (1- and 2-year-old) in order to investigate the promotory effects of priming techniques. Magnetic field treatment of 15?min was found to stimulate germination percentage and to promote seeds, resulting in 85% higher values than control seeds under real field conditions. Furthermore, seeds that were treated with magnetic field performed better in terms of early-stage measurements and root characteristics.     

Using Landsat images to map habitat availability for waterbirds in rice fields

Rice fields are an important habitat for waterbirds. Knowledge of the availability of this habitat is important since the reduction in the area of natural wetlands has converted rice fields into vital refuges. This paper presents a method for mapping habitat availability in rice fields according to different waterbirds’ habitat preferences and examining its phenology during the crop cycle. Data from bird censuses carried out in the Doñana rice fields were analysed to determine the habitat preferences of 22 species of waterbird at different stages in the rice production cycle. Discriminant function analysis of seven Landsat images was used to classify paddy field stages. The phenology of habitat availability in rice fields during autumn and winter was examined. Waterfowl and waders preferentially used the ‘flooded’ and ‘mudflats with water’ paddy field stages, respectively, and the ‘rice growing’ and ‘dry’ stages were rejected by waterbirds. The area of preferred habitats within rice fields increased during autumn; subsequently, the area of the ‘flooded’ paddy fields decreased in January, whereas that of ‘mudflats with water’ remained available until March. The automatic classification of paddy field stages with Landsat images allowed habitat availability for different species of waterbirds to be monitored and provides relevant information for understanding behavioural and population responses in waterbirds that use rice fields. After examining the phenology of the availability of habitat and comparing it with dates of arrival and departure of migrant waterbirds, best crop practices could be defined to favour waterbirds (i.e. adjusting harvest, ploughing and flooding dates). Taking into account climatic change and loss of wetlands this method could help in the integration of agriculture and conservation, in particular in areas where there is no remaining natural wetland habitat.     

Isolation and characterization of ribosomes from thoraces of the sheep blowfly,Lucilia cuprina,and their capacity for protein synthesis at different stages of development

The isolation and characterization of ribosomal fractions from thoraces of Lucilia cuprina have been described and their capacity for in vitro protein synthesis studied at different stages of development. There are large differences in the yield of ribosomes during development, and these probably reflect differences in the number of ribosomes in vivo. The amino acid incorporation activity varied at different stages of development and this variation correlated with the percentage of polysomes present. Maximal activity was found just after adult emergence. Results obtained by the use of supernatant fractions from different stages of development suggest that control of protein synthesis in this insect takes place at the level of translation.     

Steady magnetic fields effect on lipid peroxidation kinetics

The effect of steady magnetic fields (ranging from 0 to 280 mT) has been investigated on the kinetics of non-enzymatic lipid peroxidation occurring in a model system consisting of liposomes obtained from 1, 2-dioleoylphosphatidylcholine by oxygen consumption. The process was found to be accelerated by weak steady magnetic fields. A computer simulation method was employed to detect the reactions that govern the process kinetics, to elucidate magneto-sensitive stages (initiation and reduction of iron(III), as well as lipid peroxide radical recombination) and to determine their rate constants at various external magnetic fields. The kinetics of peroxidation of lipid cell membranes have been modeled mathematically at oxygen and ‘free’ iron concentrations close to those in the cells and also at increased free iron concentrations at different external magnetic field values.