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  • 11
    Electronic Resource
    Electronic Resource
    A comparison of NH4+ and NO3– net fluxes along roots of rice and maize (1998)
    Oxford, UK : Blackwell Publishing Ltd
    Plant, cell & environment 21 (1998), S. 0 
    Details
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Net fluxes of NH4+ and NO3– along adventitious roots of rice (Oryza sativa L.) and the primary seminal root of maize (Zea mays L.) were investigated under nonperturbing conditions using ion-selective microelectrodes. The roots of rice contained a layer of sclerenchymatous fibres on the external side of the cortex, whereas this structure was absent in maize. Net uptake of NH4+ was faster than that of NO3– at 1 mm behind the apex of both rice and maize roots when these ions were supplied together, each at 0·1 mol m–3. In rice, NH4+ net uptake declined in the more basal regions, whereas NO3– net uptake increased to a maximum at 21 mm behind the apex and then it also declined. Similar patterns of net uptake were observed when NH4+ or NO3– was the sole nitrogen source, although the rates of NO3– net uptake were faster in the absence of NH4+. In contrast to rice, rates of NH4+ and NO3– net uptake in the more basal regions of maize roots were similar to those near the root apex. Hence, the layer of sclerenchymatous fibres may have limited ion absorption in the older regions of rice roots.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-3040.1998.00261.x
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  • 12
    Electronic Resource
    Electronic Resource
    Salt-tolerant Triticum×Lophopyrum derivatives limit the accumulation of sodium and chloride ions under saline-stress (1989)
    Oxford, UK : Blackwell Publishing Ltd
    Plant, cell & environment 12 (1989), S. 0 
    Details
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Abstract. Cultivars of hexaploid wheat (Triticum aestivum cvs. Chinese Spring or PI 178704) and derivatives containing chromosomes from both a cultivar and a wild, salt-tolerant species (Lophopyrum elongatum or L. ponticum) were compared to determine differences in growth, ion transport and ion accumulation under salt-stress. Two experiments were conducted in which plants were grown under saline and non-saline conditions and harvested at various lime intervals throughout ontogeny. Under salt-stress the growth rate of the cultivars, as compared to the growth rate of the derivatives, decreased more rapidly later in development. Transport rates from root to shoot of Na+ and Cl− reached higher levels in the cultivars. The cultivars accumulated more Na+ and Cl− and relatively less K+ in the shoot. The K+/Na+ ratio was higher in the derivatives than in the cultivars from which they were derived. The addition of chromosomes from Lophopyrum species into wheat altered ion accumulation, growth rates, and ion transport rates from root to shoot.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-3040.1989.tb01915.x
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  • 13
    Electronic Resource
    Electronic Resource
    Water relations under root chilling in a sensitive and tolerant tomato species (2004)
    Oxford, UK : Blackwell Science Ltd
    Plant, cell & environment 27 (2004), S. 0 
    Details
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The shoots of cultivated tomato (Lycopersicon esculentum cv. T5) wilt if their roots are exposed to chilling temperatures of around 5 °C. Under the same treatment, a chilling-tolerant congener (Lycopersicon hirsutum LA 1778) maintains shoot turgor. To determine the physiological basis of this differential response, the effect of chilling on both excised roots and roots of intact plants in pressure chambers were investigated. In excised roots and intact plants, root hydraulic conductance declined with temperature to nearly twice the extent expected from the temperature dependence of the viscosity of water, but the response was similar in both species. The species differed markedly, however, in stomatal behaviour: in L. hirsutum, stomatal conductance declined as root temperatures were lowered, whereas the stomata of L. esculentum remained open until the roots reached 5 °C, and the plants became flaccid and suffered damage. Grafted plants with the shoots of one genotype and roots of another indicated that the differential stomatal behaviour during root chilling has distinct shoot and root components.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-3040.2004.01200.x
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  • 14
    Electronic Resource
    Electronic Resource
    Nitrogen isotope composition of tomato (Lycopersicon esculentum Mill. cv. T-5) grown under ammonium or nitrate nutrition (1996)
    Oxford, UK : Blackwell Publishing Ltd
    Plant, cell & environment 19 (1996), S. 0 
    Details
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Studies that quantify plant δ15N often assume that fractionation during nitrogen uptake and intra-plant variation in δ15N are minimal. We tested both assumptions by growing tomato (Lycopersicon esculetum Mill. cv. T-5) at NH4+ or NO−3 concentrations typical of those found in the soil. Fractionation did not occur with uptake; whole-plant δ15N was not significantly different from source δ15 N for plants grown on either nitrogen form. No intra-plant variation in δ15N was observed for plants grown with NH+4. In contrast. δ15N of leaves was as much as 5.8% greater than that of roots for plants grown with NO−3. The contrasting patterns of intra-plant variation are probably caused by different assimilation patterns. NH+4 is assimilated immediately in the root, so organic nitrogen in the shoot and root is the product of a single assimilation event. NO−3 assimilation can occur in shoots and roots. Fractionation during assimilation caused the δ15N of NO−3 to become enriched relative to organic nitrogen; the δ15N of NO−3 was 11.1 and 12.9% greater than the δ15N of organic nitrogen in leaves and roots, respectively. Leaf δ15N may therefore be greater than that of roots because the NO−3 available for assimilation in leaves originates from a NO−3 pool that was previously exposed to nitrate assimilation in the root.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-3040.1996.tb00010.x
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  • 15
    Electronic Resource
    Electronic Resource
    Relationships between the kinetics of NH4+ and NO3− absorption and growth in the cultivated tomato (Lycopersicon esculentum Mill, cv T-5) (1993)
    Oxford, UK : Blackwell Publishing Ltd
    Plant, cell & environment 16 (1993), S. 0 
    Details
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Tomato growth was examined in solution culture under constant pH and low levels of NH4+ or NO3−. There were five nitrogen treatments: 20 mmoles m−3 NH4+, 50 mmoles m−3 NO3−, 100 mmoles m−3 NH4+ 200 mmoles m−3 NO3−, and 20 mmoles m−3 NH4++ 50 mmoles m−3 NO3−. The lower concentrations (20 mmoles m−3 NH4+ and 50 mmoles m−3 NO3−) were near the apparent Km for net NH4+ and NO3− uptake; the higher concentrations (100 mmoles m−3 NH4+ and 200 mmoles m−3 NO3−) were near levels at which the net uptake of NH4+ or NO3− saturate. Although organic nitrogen contents for the higher NO3− and the NH4++ NO3− treatments were 22.2–30.3% greater than those for the lower NO3− treatment, relative growth rates were initially only 10–15% faster. After 24 d, relative growth rates were similar among those treatments. These results indicate that growth may be only slightly nitrogen limited when NH4+ or NO3− concentrations are held constant over the root surface at near the apparent Km concentration. Relative growth rates for the two NH4+ treatments were much higher than have been previously reported for tomatoes growing with NH4+ as the sole nitrogen source. Initial growth rates under NH4+ nutrition did not differ significantly (P≥ 0.05) from those under NO3− or under combined NH4++ NO3−. Growth rates slowed after 10–15 d for the NH4+ treatments, whereas they remained more constant for the NO3− and mixed NH4++ NO3− treatments over the entire observation period of 24–33 d. The decline in growth rate under NH4+ nutrition may have resulted from a reduction in Ca2+, K+, and/or Mg2+ absorption.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-3040.1993.tb00868.x
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  • 16
    Electronic Resource
    Electronic Resource
    Ammonium, nitrate, and proton fluxes along the maize root (1998)
    Oxford, UK : Blackwell Publishing Ltd
    Plant, cell & environment 21 (1998), S. 0 
    Details
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Ion-selective microelectrodes were used to measure NH4+, NO3– and H+ fluxes along the primary root of maize seedlings. Plants were exposed to nutrient solutions containing NH4+, NO3– or both ions. Nitrogen fluxes along the root varied substantially among the different treatments. Net NH4+ and NO3– uptake and H+ extrusion were low at the very apex of the root and generally increased in the more basal regions. In the absence of nitrogen or in the presence of NO3– alone, net H+ uptake (and root surface alkalinization) occurred at the root tip (0–1 mm), whereas net H+ extrusion occurred in all other regions. In the presence of NH4+ alone, a dramatic increase in net H+ extrusion was detected in all regions except for the region 6–11 mm from the apex. In contrast, when NO3– alone was supplied, net H+ extrusion was depressed at all locations except for the tip (0–1 mm). When both NH4+ and NO3– were supplied, NO3– uptake was suppressed at all locations while net H+ extrusion was increased relative to NO3– alone. The capacities to absorb NH4+ and NO3– at the tip were similar, as indicated by flux rates when NH4+ or NO3– were supplied as sole sources, but when supplied together, net NO3– uptake was half that of net NH4+ uptake, indicating that NH4+ may satisfy the nitrogen requirements of the poorly vascularized apical tissue in the most energy-efficient way. The high spatial resolution of the measurements enabled us to establish that acidification in the root expansion zone is maintained regardless of nitrogen source.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-3040.1998.00357.x
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  • 17
    Electronic Resource
    Electronic Resource
    Generalized joint laxity and its relation with oral habits and temporomandibular disorders in adolescent girls (2000)
    Oxford, UK : Blackwell Science Ltd
    Journal of oral rehabilitation 27 (2000), S. 0 
    Details
    ISSN: 1365-2842
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: A group of 248 girls, aged 15–16 years, were randomly selected and examined both clinically and by questionnaire with regard to the signs and symptoms of temporomandibular disorders (TMD), generalized joint laxity (GJL), range of mandibular opening, temporomandibular joint (TMJ) hypermobility and presence of oral parafunctions. The prevalence of GJL was 43% and that of TMJ hypermobility (TMJH) was 27.3%. A significant, albeit weak, correlation was found between the two. In the presence of joint click, both active and passive opening were significantly larger. When either muscle or joint sensitivity to palpation was present, the difference between the active and passive range of mouth opening increased significantly. The presence of reported clicks was negatively associated with GJL. This association was not valid in the presence of parafunction. Some of the signs and symptoms of TMD affected the range of mouth opening. In the presence of joint clicks, the mean active and passive mandibular opening were significantly larger. In the presence of joint and muscle sensitivity to palpation, the difference between passive and active mouth opening was larger. This was possibly because of the effect of pain on the full active range of opening, which was invalid in the registration of the passive mandibular opening. GJL, when present, did not seem to jeopardize the health of the stomatognathic system as expressed in the signs and symptoms of TMD. There was a negative association between GJL and the presence of reported joint clicks and catch. When a parafunction was present in addition to GJL, this association was invalid but not reversed, as has been previously reported.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2842.2000.00546.x
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  • 18
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    Unknown
    The sense of sin and guilt and the last age (Mappo) in Chinese and Japanese Buddism (1967)
    Leyden : Periodicals Archive Online (PAO)
    Numen. 14:2 (1967:July) 144 
    Details
    ISSN: 0029-5973
    Topics: History , Theology and Religious Studies
    URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pao:&rft_dat=xri:pao:article:4146-1967-014-02-000005
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  • 19
    Electronic Resource
    Electronic Resource
    Cloning Human Lymphocytes in vitro (1970)
    [s.l.] : Nature Publishing Group
    Nature 227 (1970), S. 171-173 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The potentiality of human peripheral lymphocytes themselves to act as precursor cells has been demonstrated in vitro by the cloning of established lymphocytoid cell lines in semisolid agar4. But this system does not allow for the direct visualization of single cells embedded in agar, so that growth ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/227171a0
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  • 20
    Electronic Resource
    Electronic Resource
    Cytogenetic Study of the Offspring of Atom Bomb Survivors (1968)
    [s.l.] : Nature Publishing Group
    Nature 218 (1968), S. 367-368 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] This cytogenetic study was designed to evaluate the sensitivity to radiation of human germ cell chromosomes, on the assumption that subtle but detectable chromosomal rearrangements induced in the meiotic chromosomes of an exposed parent would be reflected in the somatic cells of the progeny, even ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/218367a0
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