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  • 11
    ISSN: 1471-0528
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Objective To examine the relation between indices of maternal nutrition during pregnancy, including haemoglobin concentration, skinfold thickness and body weight, and the child's blood pressure at 10 to 12 years of age.Design Follow up study of children whose mothers had haemoglobin estimations, weights and skinfold thicknesses recorded during pregnancy.Setting Kingston, Jamaica.Subjects Seventy-seven children whose mothers took part in a prospective study of nutrition during pregnancy in relation to fetal growth.Main outcome measure Blood pressure at 10 to 12 years of age.Results The child's mean systolic pressure adjusted for current weight rose by 2.6 mmHg (95 % CI 0.5–4.6, P= 0.01) for each 1 g/dl fall in the mother's lowest haemoglobin during pregnancy. Mothers with a lower haemoglobin had thinner skinfold thicknesses, especially over the triceps (P= 0.005). In multiple regression analyses, taking account of the child's sex and current weight, there was a strong association between thin maternal triceps skinfold thickness at 15 weeks of gestation and raised blood pressure in the offspring. Taking account of the mother's triceps skinfold thickness abolished the relation between lower haemoglobin and raised blood pressure in the child. Lower weight gain between 15 and 35 weeks of gestation was independently associated with raised children's blood pressure. Systolic pressure rose by 10.7 mmHg (95 % CI 5.7 to 15.6, P= 0.0001) for each log mm decrease in the mother's triceps skinfold thickness, and by 0.6 mmHg (95% CI 0.1 to 1.0, P= 0.02) for each 1 kg decrease in the mother's weight gain during pregnancy.Conclusions These results parallel animal experiments suggesting that impaired maternal nutrition may underlie the programming of adult hypertension during fetal life.
    Type of Medium: Electronic Resource
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  • 12
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Clinical & experimental allergy 24 (1994), S. 0 
    ISSN: 1365-2222
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Summary. A follow-up study was carried out to determine whether either impaired or disproportionate fetal growth are associated with a raised total serum IgE concentration in men and women aged 50 years. The serum IgE concentration was measured in 146 men and 134 women born in Preston (Lancashire, UK) between 1935 and 1943, whose size at birth had been measured in detail.Sixty-two subjects were found to have an IgE concentration above 80 IU/ml. Compared with subjects with a normal IgE on average they had a 0.30 inch larger head circumference at birth (P -0.004) and weighed 5.6 ounces more at birth (P= 0.04). People with a raised and with a normal IgE were of similar crown-heel length at birth, indicating that in utero those with a raised IgE had had disproportionate growth of the head in relation to the trunk and limbs. The prevalence of a raised IgE rose from 14% in subjects whose head circumference at birth was 13 inches or less to 37% in those whose head circumference was more than 14 inches. This association was independent of gestational age at birth and of the mother's pelvic size and parity. It was also independent of adult physique, social class and smoking, and was similar in men and women. In multiple logistic regression analyses odds ratios of a raised IgE rose progressively to more than 4 as head circumference at birth increased from 13 inches or less to more than 14 inches.One possibility is that these associations reflect the long-term effects of sustaining fetal brain growth at the expense of the trunk, in particular the thymus. This may be a consequence of fetal under-nutrition in late gestation.
    Type of Medium: Electronic Resource
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  • 13
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Grass and forage science 52 (1997), S. 0 
    ISSN: 1365-2494
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Appropriate pre-sowing methods for the introduction of improved forage legume and grass germplasm are an important issue for hill pasture improvement in New Zealand. A pastoral fallow, which involves not defoliating pasture for a period generally from late spring/early summer to autumn, could create a potentially favourable environment for introducing improved germplasm. A field study was conducted on two aspects (shady and sunny) of moist, low-fertility hill country with or without added fertilizer (phosphorus and sulphur) in the southern North Island of New Zealand, to investigate the changes in plant population density and sward structure during a full or partial pastoral fallow, compared with a rotationally grazed pasture. A 7-month (October to May) pastoral fallow dramatically decreased the densities of grass tillers by 72% (P 〈 0·01), white clover (Trifolium repens L.) growing points by 87% (P 〈 0·01) and other species by 87% (P 〈 0·05). The decline in tiller density by pastoral fallow was enhanced on the shady aspect. Fertilizer application increased white clover growing-point density on the shady aspect (P 〈 0·05) and grass tiller density on the sunny aspect (P 〈 0·05). Decreased plant density during pastoral fallowing was attributed to aboveground biomass accumulation, which altered sward structure, leading to interplant competition and mortality by self-thinning and completion of the life cycle of some matured plants. The plant size-density relationship during pastoral fallowing in this mixed-species sward followed the serf-thinning rule, particularly when the calculation was based on all plant species rather than grass alone. There was no significant (P 〉 0·05) difference in final plant population density between the 7-month pastoral fallow and a shorter term (October to December) pastoral fallow. It is concluded that pastoral fallowing effectively reduced the plant population density and altered sward structure of a hill pasture. Such changes create a more favourable environment for the introduction of improved forage species.
    Type of Medium: Electronic Resource
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  • 14
    ISSN: 1471-0528
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Objective— To examine the maternal influences which determine large placental weight and a high ratio of placental weight to birthweight. These are known predictors of adult blood pressure.Design— Retrospective analysis of routine obstetric and haematology department records for a large cohort of pregnant women.Setting— John Radeliffe Hospital, Oxford.Subjects— 8684 pregnant women who were delivered between January 1987 and January 1989 and whose records could be linked to the results of two or more pregnancy blood counts.Main outcome measures— Placental weight and the ratio of placental weight to birthweight.Results— Large placental weight was associated with a low maternal haemoglobin and a fall in maternal mean cell volume during pregnancy. The highest ratio of placental weight to birthweight occurred in the most anaemic women with the largest falls in mean cell volume. Large placental weight and a high ratio of placental weight to birthweight were also independently associated with a high maternal body mass index. Maternal smoking reduced placental weight, but increased the ratio of placental weight to birthweight.Conclusions— Anaemia and iron deficiency during pregnancy are associated with large placental weight and a high ratio of placental weight to birthweight. This points to maternal nutritional deficiency as a cause for discordance between placental and fetal growth. This may have important implications for the prevention of adult hypertension, which appears to have its origin in fetal life.
    Type of Medium: Electronic Resource
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  • 15
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd, UK
    Plant, cell & environment 21 (1998), S. 0 
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The evergreen species Yucca glauca was characterized at the end of September and following exposure to low temperatures at the end of November. In November the diurnal pattern of xanthophyll cycle-dependent energy dissipation was altered such that this thermal dissipation process was engaged at a high level throughout the day, whereas in September it only became engaged when leaves received direct sunlight. An analysis of the diurnal partitioning of the absorbed excitation energy into photochemistry versus thermal dissipation suggested that a smaller fraction of that energy was utilized in photochemistry and a greater fraction was dissipated thermally at the end of November compared to September. Lower ratios of Chl a/b and β-carotene/xanthophylls both suggested a decrease in the ratio of reaction centre plus core antenna proteins compared to light-harvesting proteins, and a lower leaf chlorophyll content suggested a decrease in light-harvesting capacity in November versus September. Thus adjustments to the photosynthetic apparatus occurred on several levels in response to the increase in excess excitation energy that Y. glauca experienced during the onset of winter.
    Type of Medium: Electronic Resource
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  • 16
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Leaves of Stephania japonica and Smilax australis were characterized in situ on the coast of north-eastern New South Wales, Australia, where they were growing naturally in three different light environments: deep shade, in the understory of an open Eucalyptus forest where they received frequent sunflecks of high intensity, and in an exposed site receiving full sunlight. In deep shade the xanthophyll cycle remained epoxidized during the day and the vast majority of absorbed light was utilized for photosynthesis. In the exposed site both deepoxidation and epoxidation of the xanthophyll cycle and changes in the level of xanthophyll-dependent thermal energy dissipation largely tracked the diurnal changes in photon flux density (PFD). In the understory the xanthophyll cycle became largely deepoxidized to zeaxanthin and antheraxanthin upon exposure of the leaves to the first high intensity sunfleck and this high level of deepoxidation was maintained throughout the day both during and between subsequent sunflecks. In contrast, thermal energy dissipation activity, and the efficiency of photosystem II, fluctuated rapidly in response to the changes in incident PFD. These findings suggest a fine level of control over the engagement of zeaxanthin and antheraxanthin in energy dissipation activity, presumably through rapid changes in thylakoid acidification, such that they became rapidly engaged for photoprotection during the sunflecks and rapidly disengaged upon return to low light when continued engagement might limit carbon gain.
    Type of Medium: Electronic Resource
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  • 17
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Plant, cell & environment 20 (1997), S. 0 
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Leaves of the CAM plant Cotyledon orbiculata produced a dense epidermal wax which decreased the absorption of light, possibly functioning as an external photoprotective mechanism (Robinson et al. 1993). However, developing leaves did not accumulate wax until after 21 d with full wax coating not achieved until at least 35 d. In addition, young leaves had lower rates of electron transport than mature leaves. Leaf development therefore occurs at higher incident PFD than that experienced by the mature leaves, and, for young leaves, can lead to an increase in the proportion of light energy which is excess to requirements and must be dissipated non-photochemically. Changes in the photosynthetic capacity, PSII efficiency, rate of energy dissipation, and the content of chlorophyll (Chi), carotenoids, wax and anthocyanins were followed in developing leaves of C. orbiculata in an attempt to elucidate the relative importance of the various photoprotective mechanisms during leaf ontogeny. The largest pools of xanthophyll cycle pigments (on a Chi basis) were found in the waxless, young leaves and were correlated with greater levels of energy dissipation activity. The importance of xanthophyll cycle-dependent energy dissipation in young C. orbiculata leaves prior to development of a reflective wax covering, and full photosynthetic capacity which for CAM plants includes appreciable nocturnal acid accumulation, is discussed. Also, we consider the possibility that anthocyanin pigments in the upper and lower epidermis may increase reflectivity and act as external photoprotectants.
    Type of Medium: Electronic Resource
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  • 18
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The influence of the growth photon flux density (PFD) on the size and composition of the carotenoid pool and the size of the reduced ascorbate pool was determined across a light gradient from the forest floor to the canopy and the forest edge of a sub-tropical rainforest in New South Wales, Australia. Nineteen plant species (most collected from multiple sites) representing a broad taxonomic range consistently possessed larger total carotenoid pools when found growing in more exposed sites. There was a significant positive correlation between β-carotene content and growth PFD and a significant negative correlation between α-carotene content and growth PFD. Neoxanthin content exhibited no significant trend while the trend in lutein content varied with mode of expression. The pigments of the xanthophyll cycle (violaxanthin, antheraxanthin and zeaxanthin) exhibited the most pronounced response to growth PFD; they comprised a much greater portion of the total carotenoid pool in high light-acclimated plants. The pool of reduced ascorbate was also several-fold greater in high light-acclimated plants. These acclimatory changes in carotenoid and ascorbate content are consistent with a need for a greater capacity to dissipate excessive absorbed light energy in high light-acclimated plants.
    Type of Medium: Electronic Resource
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  • 19
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 84 (1910), S. 363-363 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] AN article in NATURE for August 18 deals aptly with the question of testing for colour-vision. It is to be hoped that the committee at present inquiring into the matter will advocate that testing should be carried out in future in conditions resembling as nearly as possible those on which ...
    Type of Medium: Electronic Resource
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  • 20
    Electronic Resource
    Electronic Resource
    Springer
    Meteorology and atmospheric physics 60 (1996), S. 3-17 
    ISSN: 1436-5065
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography , Physics
    Notes: Summary We compare radiosonde observations of relative humidity with NWP versions of the Meteorological Office Unified Model, and attempt to understand the causes of the systematic differences seen. The differences are found to have a different structure in cyclonic and anticyclonic situations over the UK. In cyclonic situations the mid-tropospheric temperature and humidity differences could be due to model biases, consistent with the conservation of energy; the latent heating from precipitation of the model's excess moisture would remove the model's cold bias. There is also some evidence for observational bias. Wetting of the sonde sensor in cloud can cause a moist bias at higher levels. The Väisala RS80 sonde also appears to have a dry bias near saturation. The Unified Model has a parameterisation for stratiform cloud which calculates the fractional cloud cover in a gridbox from the box-average relative humidity, allowing for sub-grid-scale variability within the box. This scheme has been tuned to give reasonable cloud amounts with the model's relative humidities. The cloud amounts implied (by the scheme) for radiosonde relative humidities are systematically less than the observed cloud. So assimilation of the observed humidities can significantly degrade analyses and predictions of cloud. Bias corrections for the radiosonde humidities have been calculated to compensate for this. Experiments have been performed to test the effect of the bias correction on the assimilation and prediction of cloud and precipation. With the control system, cloud cover and precipitation spins-up during the forecast period; the bias correction improves this. A large improvement was also found when the relationship between the temperature and humidity assimilation was changed; it is better to assume that temperature and relative humidity errors are uncorrelated, rather than temperature and specific humidity.
    Type of Medium: Electronic Resource
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