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101.
1. A study of the mode of combination which takes place between certain amino acids, proteins, various carboxylic acids, and certain sulfonic acids and manganous ions to form complexes is reported. 2. Three criteria for complex formation were used: (a) the equilibrium between the substance under test and manganous ions dissolved in aqueous buffered solution and isonitrosoacetophenone dissolved in chloroform; (b) the electrophoretic migration of manganese in the presence of the test substance with varying pH; and (c) anomalous titration. 3. The following classes of substances were found to possess the necessary groupings to form manganese complexes: hydroxy-monocarboxylic acids (lactic, gluconic), dicarboxylic acids (oxalic, malonic), hydroxy-, di- and tricarboxylic acids (citric, tartaric), dicarboxylic amino acids (aspartic, glutamic), certain inorganic acids (phosphoric, sulfuric), certain phosphoric acid-containing compounds (nucleic, glycerophosphoric), certain aromatic enol sulfonic acids (phenolsulfonic, catecholsulfonic), and certain proteins (casein, edestin, gelatin). 4. A correlation between the amount of manganese bound by the several proteins and the free carboxyl and phosphoric acid groups has been made. 5. An explanation based on the residual charge of certain atoms is advanced for the manner in which divalent manganese may be united by the compounds studied. 相似文献
102.
The present study was carried out in 3 villages, namely Kafr Ayoub Soliman, Kafr Ibrahim El-Aidi, and El-Sa'adat, Sharqiya Governorate, Egypt. A total of 519 rats was collected from the 3 study sites: 46.6% Rattus rattus, and 53.4% Rattus norvegicus. A total of 20,643 ectoparasites was recovered from R. rattus: 33.3% mites, 33.8% fleas, and 32.9% lice. From R. norvegicus a total of 40,997 ectoparasites was recovered: 28.9% mites, 31% fleas, and 40.1% lice. Three common mite species were recovered from both rat hosts, i.e., Ornithonyssus bacoti, Radfordia ensifera, and Laelaps nuttalli. Three common flea species were also recovered from both rat hosts, i.e., Echidnophaga gallinacea, Leptopsylla segnis, and Xenopsylla cheopis. Polyplax spinulosa was the only dominant louse species that infested both rat hosts. Rats did not show a definite breeding season, and the seasonal rat indices were generally low in different study sites. There were no significant differences between the prevalence of each of mites, fleas, and lice in both rat species. The total general indices of mites and fleas, on the other hand, was significantly higher in R. norvegicus. The general index of X. cheopis was high and ranged between 5.9 in R. rattus and 14.5 in R. norvegicus. Season-related changes were observed in the general index of each of L. segnis infesting both rat species and R. ensifera and O. bacoti infesting R. norvegicus. The prevalence and general indices of some ectoparasites showed differences related to the locality of their rat hosts. Seasonal changes in the general indices of some ectoparasites paralleled seasonal changes in the relative abundance of their rat hosts. 相似文献
103.
BY A. d'A. BELLAIRS 《Journal of Zoology》1965,144(2):239-252
Six embryos of the eyed lizard ( Lacerta lepida ) with malformations such as short upper jaw, microphthalmia, abnormal fore-brain, cleft palate, absence or deficiency of the pituitary and tail defects are described. Embryos of the common lizard ( Lacerta vivipara ) and adder ( Vipera berus ) with microphthalmia and cleft palate, and of a sand lizard ( Lacerta agilis ) showing partial Siamese twinning are also reported. The aetiology of these malformations, and the well-known occurrence of similar conditions in birds and mammals, is discussed. 相似文献
104.
105.
Tae-Jin Lee Pete E. Pascuzzi Sharon B. Settlage Randall W. Shultz Milos Tanurdzic Pablo D. Rabinowicz Margit Menges Ping Zheng Dorrie Main James A. H. Murray Bryon Sosinski George C. Allen Robert A. Martienssen Linda Hanley-Bowdoin Matthew W. Vaughn William F. Thompson 《PLoS genetics》2010,6(6)
DNA replication programs have been studied extensively in yeast and animal systems, where they have been shown to correlate with gene expression and certain epigenetic modifications. Despite the conservation of core DNA replication proteins, little is known about replication programs in plants. We used flow cytometry and tiling microarrays to profile DNA replication of Arabidopsis thaliana chromosome 4 (chr4) during early, mid, and late S phase. Replication profiles for early and mid S phase were similar and encompassed the majority of the euchromatin. Late S phase exhibited a distinctly different profile that includes the remaining euchromatin and essentially all of the heterochromatin. Termination zones were consistent between experiments, allowing us to define 163 putative replicons on chr4 that clustered into larger domains of predominately early or late replication. Early-replicating sequences, especially the initiation zones of early replicons, displayed a pattern of epigenetic modifications specifying an open chromatin conformation. Late replicons, and the termination zones of early replicons, showed an opposite pattern. Histone H3 acetylated on lysine 56 (H3K56ac) was enriched in early replicons, as well as the initiation zones of both early and late replicons. H3K56ac was also associated with expressed genes, but this effect was local whereas replication time correlated with H3K56ac over broad regions. The similarity of the replication profiles for early and mid S phase cells indicates that replication origin activation in euchromatin is stochastic. Replicon organization in Arabidopsis is strongly influenced by epigenetic modifications to histones and DNA. The domain organization of Arabidopsis is more similar to that in Drosophila than that in mammals, which may reflect genome size and complexity. The distinct patterns of association of H3K56ac with gene expression and early replication provide evidence that H3K56ac may be associated with initiation zones and replication origins. 相似文献
106.
Isolation of corn stunt spiroplasma in Jamaica, and probable dual infection with maize mosaic virus 总被引:2,自引:0,他引:2
Females of Cydia ptychora oviposited on cowpea, Vigna unguiculata ssp. unguiculata in the field between 18.00 and 19.00 h commencing about 30 days after planting with a few eggs laid on the leafbuds and the undersides of leaves. Oviposition increased as the host plant developed the preferred sites, floral sepals and their remains on pods, and peaked at about 58 days after planting regardless of planting date. First instar larvae were found wandering on the plant between 06.45 and 11.15 h but other larval instars were rarely encountered outside the pod except when changing pods or leaving pods to pupate in the soil. Contrary to previously reported observations, larval development occurred in leafbuds and inside flowers both in the field and in laboratory rearing. Development was optimal on pods, and mortality was high in leafbuds. 相似文献
107.
Urinary growth hormone (u-GH) excretion was measured in 547 healthy children and 110 adults by ELISA with a detection limit of 1.1 ng/l u-GH after prior concentration of the urine samples (20- to 30-fold). u-GH excretion values were significantly dependent on the pubertal stage (p less than 0.0001) with maximum values in Tanner stage 3 for girls and 4 for boys. This corresponded to a peak in u-GH excretion between 11.5-14.5 years in girls and 12.5-16 years in boys. Additionally, u-GH excretion in adults was significantly higher than in prepubertal children (p less than 0.001). The day/night ratio of u-GH excretion (pg/h) was significantly higher in females than in males (p less than 0.01). In Tanner stages 1-4, u-GH excretion during the day was lower than that at night, whereas the opposite was true in late puberty and in adult women. The interindividual variation of u-GH excretion within the same Tanner stage was considerable and approximately double the intraindividual variation. The day-to-day variation could be further reduced by collection of three consecutive urine samples. The variations were larger if night samples instead of 24-hour samples were considered. The expression of u-GH excretion in nanograms per gram creatinine did not diminish the observed variation and blunted the pubertal increase in u-GH excretion. In conclusion, (1) u-GH excretion depends significantly on age, sex and pubertal maturation as does the day/night ratio of u-GH excretion. (2) The interindividual variation in u-GH excretion is considerable.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
108.
Jill L. Wegrzyn John D. Liechty Kristian A. Stevens Le-Shin Wu Carol A. Loopstra Hans A. Vasquez-Gross William M. Dougherty Brian Y. Lin Jacob J. Zieve Pedro J. Martínez-García Carson Holt Mark Yandell Aleksey V. Zimin James A. Yorke Marc W. Crepeau Daniela Puiu Steven L. Salzberg Pieter J. de Jong Keithanne Mockaitis Doreen Main Charles H. Langley David B. Neale 《Genetics》2014,196(3):891-909
The largest genus in the conifer family Pinaceae is Pinus, with over 100 species. The size and complexity of their genomes (∼20–40 Gb, 2n = 24) have delayed the arrival of a well-annotated reference sequence. In this study, we present the annotation of the first whole-genome shotgun assembly of loblolly pine (Pinus taeda L.), which comprises 20.1 Gb of sequence. The MAKER-P annotation pipeline combined evidence-based alignments and ab initio predictions to generate 50,172 gene models, of which 15,653 are classified as high confidence. Clustering these gene models with 13 other plant species resulted in 20,646 gene families, of which 1554 are predicted to be unique to conifers. Among the conifer gene families, 159 are composed exclusively of loblolly pine members. The gene models for loblolly pine have the highest median and mean intron lengths of 24 fully sequenced plant genomes. Conifer genomes are full of repetitive DNA, with the most significant contributions from long-terminal-repeat retrotransposons. In depth analysis of the tandem and interspersed repetitive content yielded a combined estimate of 82%. 相似文献
109.
BACKGROUND/AIMS: Growth hormone (GH) excess in childhood is a rare disorder. Current treatment options such as somatostatin analogues, pituitary surgery or irradiation can have serious side effects. Recently, a GH receptor antagonist, pegvisomant, was introduced for the treatment of adults with acromegaly. We wanted to investigate whether pegvisomant was effective in a child with octreotide-resistant GH excess. CASE: A 4-year-old girl with neurofibromatosis type 1 and GH excess associated with optic glioma received pegvisomant injections (10 mg subcutaneously) with increasing intervals from daily to every 4th day. RESULTS: IGF-I and IGFBP-3 decreased from +6.9 and 4.6 standard deviation scores (SDS), respectively, to within normal range. Height velocity dropped from 12.4 SDS to mean -0.7 SDS (range: -5.0 to 5.0) and height SDS decreased from +1.3 to +0.6 (target height: +0.2). Random non-fasting serum GH values were mean 5.0 mlU/l (range: 1.6-9.5). There was no change in fasting blood glucose (4.6-4.7 mmol/l) or glycosylated haemoglobin (5.5%) and no subjective or biochemical side effects. Repeated tests of thyroid, adrenal and gonadal function showed no alterations during the treatment period. Intracranial tumours remained unchanged in size and visual impairment did not deteriorate. CONCLUSION: Pegvisomant normalized IGF-I and IGFBP-3 levels. Growth velocity was normalized after initial catch-down growth, and it remains to be seen whether this result can be maintained during long-term treatment. 相似文献
110.