The inheritance of size and shapes in plants

Ohne Zusammenfassung

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The inheritance of size and shapes in plants

     

Accuracy and Reliability of Severity Estimates Using Linear or Logarithmic Disease Diagram Sets in True Colour or Black and White: a Study Case for Rice Brown Spot

Four disease diagram sets to aid in assessments of rice brown spot severity were developed and evaluated with regard to accuracy and reliability of the estimates. These sets had severity increments in a linear (LIN) or logarithmic (LOG) fashion with the diagrams depicted in true colour (COL) or black and white (BW). Ten inexperienced raters evaluated one of the sets, totalling forty raters. On each group of raters, the assessment was made first unaided and then aided with the respective diagram set. The minimum and the maximum severities of the diagram sets were 0.5 and 36%, respectively, and the five intermediate severity values were 6, 12, 18, 24 and 32% for the LIN diagram sets, and 1.8, 3.3, 6, 11 and 20% for the LOG sets. Overall agreement, measured by the Lin's concordance correlation coefficient (ρ_c), increased considerably when using the aid (unaided mean ρ_c = 0.53, aided mean ρ_c = 0.87) due to a strong reduction in the systematic bias, measured by the bias correction factor C_b (unaided mean C_b = 0.60, aided mean C_b = 0.95). All diagrams led to similar accuracy and precision, but a consistent overestimation was still observed when using the LIN sets, and variability for the absolute errors was higher for the LOG sets, compared with the LIN sets. Estimates using the diagram sets were more reliable based on the intraclass correlation (mean ρ = 0.79–0.86) compared with unaided estimates (mean ρ = 0.51–0.67). Raters exhibited preference for specific values, such as the ‘knots’ (10, 20, 30%, etc.), and the severity values represented in the diagrams, especially when using the LIN sets. The diagram sets similarly helped to improve accuracy and reliability of estimates of rice brown spot epidemics.     

E‐ADA activity in lymphocytes of an experimental model of pythiosis treated with immunotherapy

Pythiosis is a life‐threatening disease caused by the oomycete Pythium insidiosum. Some authors have suggested the involvement of a Th2‐like immune response in the infected host, which leads to extensive tissue damage. The switch from a Th2 to a Th1 response pattern is one hypothesis to explain the curative properties of immunotherapy. Taking into account the importance of immunotherapy for pythiosis treatment and the contribution of adenine nucleotides in the immunoregulation of the host, we evaluated the ecto‐adenosine deaminase (E‐ADA; EC 3·5.4·4) activity in lymphocytes from rabbits inoculated with P. insidiosum. Rabbits were inoculated with 1 milliliter of zoospores subcutaneously injected into the lateral thorax; after developing lesions, the rabbits received eight doses of immunotherapy. E‐ADA activity was measured in lymphocytes and the adenine nucleotides and adenosine levels were quantitatively determined in serum. Rabbits with characteristic lesions of pythiosis showed a decreased E‐ADA activity (82·36%), a decreased adenosine triphosphate concentration (54·04%) and a higher adenosine concentration (2·51 fold), when compared with controls, after 28 days of inoculation. However, after the immunotherapy, the rabbits showed an increase in the E‐ADA activity when compared with control (78·62%), contributing for the change in the immune response. Our results reinforce the hypothesis that the change from a Th2 to a Th1 immune response with the participation of the purinergic system could be responsible for the curative properties of immunotherapy. Copyright © 2012 John Wiley & Sons, Ltd.     

Exploratory analysis of diffusion tensor imaging in children with attention deficit hyperactivity disorder: evidence of abnormal white matter structure

Abnormalities in the white matter microstructure of the attentional system have been implicated in the aetiology of attention deficit hyperactivity disorder (ADHD). Diffusion tensor imaging (DTI) is a promising magnetic resonance imaging (MRI) technology that has increasingly been used in studies of white matter microstructure in the brain. The main objective of this work was to perform an exploratory analysis of white matter tracts in a sample of children with ADHD versus typically developing children (TDC). For this purpose, 13 drug-naive children with ADHD of both genders underwent MRI using DTI acquisition methodology and tract-based spatial statistics. The results were compared to those of a sample of 14 age- and gender-matched TDC. Lower fractional anisotropy was observed in the splenium of the corpus callosum, right superior longitudinal fasciculus, bilateral retrolenticular part of the internal capsule, bilateral inferior fronto-occipital fasciculus, left external capsule and posterior thalamic radiation (including right optic radiation). We conclude that white matter tracts in attentional and motor control systems exhibited signs of abnormal microstructure in this sample of drug-naive children with ADHD.     

Hepatitis E Virus Genotype 1 Infection of Swine Kidney Cells In Vitro Is Inhibited at Multiple Levels

Genotype 1 hepatitis E viruses (HEVs) are restricted to primate hosts, whereas genotype 3 HEVs predominantly infect swine, in addition to primates. In order to identify possible determinants of the host range, infectious recombinant viruses and chimeras of a genotype 1 isolate and a genotype 3 isolate were compared for their ability to infect versus transfect cultured human HepG2/C3A cells and swine LLC-PK cells. The patterns of luciferase expression from virus replicons containing the Gaussia luciferase gene in place of the viral ORF2 or ORF3 genes demonstrated that translation of the ORF2 capsid gene of genotype 1 virus is severely inhibited in swine kidney cells compared to its translation in rhesus macaque kidney or human liver cells. Therefore, this virus may produce insufficient capsid protein for optimal assembly in swine cells. Infectivity assays with a virus containing a chimeric capsid protein confirmed that amino acids 456 to 605 of the virus capsid protein comprised the virus receptor-binding region and suggested that genotype 1 viruses may be prevented from infecting swine because genotype 1 viruses are unable to enter swine cells. Rhesus macaque cells appeared to be better than human cells for growing the genotype 1 virus. These cell and virus combinations may serve as a useful in vitro model with which to study determinants of the natural host range of this virus.     

THE EFFECT OF WAVELENGTH AND INTENSITY OF LIGHT ON THE PROPORTION OF PIGMENTS IN PORPHYRIDIUM CRUENTUM

Brody , Marcia , and Robert Emerson . (U. Illinois, Urbana.) The effect of wavelength and intensity of light on the proportion of pigments in Porphyridium cruentum. Amer. Jour. Bot. 46(6): 433–440. Illus. 1959.—We specify a medium for Porphyridium cruentum made from distilled water and inorganic salts, without addition of earth extract, sea water or other supplements of uncertain composition, which sustains excellent growth through successive transfers. By control of intensity and wavelength of light used for growing the cultures, we have found it possible to vary the concentrations of chlorophyll and phycoerythrin, and also the proportions of these 2 pigments, over a considerable range. The changes in proportion of red and green pigments, in response to culturing in green and in blue light, are opposite to the changes that would be predicted from Engelmann's theory of complementary chromatic adaptation, when the intensities of the blue and green light are of the order of 10⁴ ergs/cm²/sec. (or greater). However, at about 1/100 of this intensity, the changes are in the direction of complementary chromatic adaptation.