Various Stages Of Maturity Research Articles

Recombinant adeno-associated virus type 2 mediates highly efficient gene transfer in regenerating rat skeletal muscle.

The recent identification of genes responsible for several muscle diseases, particularly inherited myopathies, has made gene transfer to pathologic muscle tissue an attractive research field. As early pathologic changes in myopathic muscle involve repeated necrosis-regeneration cycles, leading to the coexistence of myofibers at different stages of maturity, a delivery system for efficient, durable gene therapy of inherited muscle diseases should allow gene transfer into myofibers at any stage of maturity. Experiments with rat skeletal muscles showed that recombinant adeno-associated virus (rAAV) type 2 can be highly efficient and even improve gene transfer in regenerating as compared with mature muscle, provided that vector injection is performed during the myotube growth period of the regenerative process. At this early period of muscle regeneration, young regenerating myotubes strongly express heparan sulfate proteoglycan AAV type 2 receptor. Improvement was associated with a greater number of transduced myofibers in muscle samples and an increase in viral genomic copies in transduced muscle. No significant deleterious effects on muscle phenotype or any evident alterations in the regenerative process were observed in transduced muscles. Unlike other available viral vectors, whose transduction efficiencies are highly maturation-dependent, rAAV type 2-based vectors provide efficient in vivo gene transfer in myofibers at various stages of maturity, making AAV a promising delivery system for pathological muscle tissue.

Digital Photoelasticity: Advanced Techniques and Applications

Digital Photoelasticity: Advanced Techniques and Applications

Nitrogen Transformation Processes Taking Place During the Intensive Phase of Composting

N transformation processes taking place during the intensive phase of composting were analyzed for characteristic compost raw materials in an adiabatic composting bioreactor by analyzing composts (in various stages of maturity), emitted gases and leakage water. Temperature exhibited a similar curve for all raw materials, with a gradual decrease in compost temperature from day 11-13 on. Measurements of NH 3 indicated a significant difference between the various raw materials, sometimes amounting to an order of magnitude, in the quantitative data of NH 4 volatilization. Analysis of leakage water indicated that ammonification and nitrification processes could be traced satisfactorily, but the quantity of leakage water formed in the adiabatic drum composter and the associated N losses were negligible compared to the total N cycle of compost formation. Analysis of the composts showed that the organic matter content of the samples declined during composting as the result of biodegradation.

Determination of the respiration rate of tomato fruit using flow analysis

A continuous-flow method using a conductometric detector was developed to measure CO2 resulting from respiration of tomato fruit (Lycopersicon esculentum var. Santa Clara). The fruit are inserted into a 3.4-l vessel and the atmosphere in the vessel continuously monitored for CO2, using a closed-loop system. The CO2 produced from fruit respiration diffuses through a Teflon ® membrane, dissociates in the acceptor stream of deionized water, and the conductivity (mainly of H and HCO3 ) is monitored. The conductance increase in the acceptor stream is proportional to the carbon dioxide concentration in the gaseous sample. Each determination is performed in 7 min, a time interval short enough to prevent respiration inhibition due to high levels of CO2 inside the respiration vessel. The relative error of measurement is 3.0% (n7) for a CO2 level of 589 ppmv. Average respiration rates for the tomatoes var. Santa Clara of various stages of maturity ranged from 40 to 120 mg kg 1 h 1 evolved CO2. These results had low levels of variance between measurements, were consistent between repetitions, and were comparable with published data. © 2001 Elsevier Science B.V. All rights reserved.

Shortwave Ultraviolet Irradiation for Control of Decay Caused by Botrytis cinerea in Bell Pepper: Induced Resistance and Germicidal Effects

Shortwave ultraviolet radiation (UV-C) was tested for controlling natural infections and inducing resistance to fungal decay caused by Botrytis cinerea Pers.: Fr. (gray mold rot) in bell pepper [Capsicum annuum L. var. annuum (Grossum Group)] fruit. All UV-C doses tested (0.22, 0.44, 0.88, or 2.20 kJ·m-2) caused a reduction in the number of natural infections occurring during storage at 13 °C. A UV-C dose of 0.88 kJ·m-2 controlled most effectively natural infections in peppers stored at both 13 or 20 °C. Although UV-C was found to be highly germicidal to B. cinerea conidia exposed on agar or on fruit wounds, it did not prevent infection of fruit inoculated with the pathogen 24 hours before exposure to UV-C. However, fruit which were exposed to UV-C 24 hours before inoculation with B. cinerea had a lower percentage of infections. For this reason, UV-C appears to act mainly as an inducer of disease resistance in this crop rather than a sanitizing agent. UV-C was effective in inducing resistance to B. cinerea in fruit at various stages of maturity, from green to red. Disease resistance was also induced in fruit which had been stored for 7 days before UV-C treatment. The effect of UV-C doses was found to be additive as two successive exposures at 0.44 kJ·m-2 had an equivalent effect as one exposure to the optimal dose of 0.88 kJ·m-2. However, two successive exposures to 0.88 kJ·m-2 were less effective than one exposure to this dose.

Boll openers in cotton: effectiveness and environmental influences

The indeterminate growth of cotton ( Gossypium hirsutum L.) often results in a boll population at various stages of maturity when the crop is harvested. Boll opening compounds can be used to facilitate harvest by accelerating the opening of green bolls. Field trials were conducted at two locations in 1996 and 1997 to test the efficacy of four commercially available boll openers that stimulate ethylene production or desiccate the plant. Two of these boll openers are new to the marketplace: Finish™, ethephon+cyclanilide (2-chloroethyl phosphonic acid+1-(2,4-dichlorophenylaminocarbonyl)-cyclopropane carboxylic acid), and CottonQuick™, ethephon+AMADS (2-chloroethyl phosphonic acid+1-aminomethanamide dihydrogen tetraoxosulfate). Open bolls were hand harvested at 3–7 days intervals after application of the boll openers, and environmental conditions in conjunction with these harvests were recorded. The desiccant, paraquat (1,1′-dimethyl-4,4′-bipyridinium dichloride), was found to have erratic boll opening activity. Two products that contain ethephon plus the synergists cyclanilide or AMADS were found to have equal or higher rates of boll opening than ethephon alone. The rate of boll opening of all compounds was influenced more by the accumulation of heat units than by the amount of time following the application of boll openers. Although erratic, boll opening activity from paraquat application can be significant. Moreover, the reliability of ethephon based products, which are consistent boll openers, may be enhanced by formulations that contain a synergist. Heat unit accumulation may be used to predict and model the efficacy of boll opening with these harvest aides.

Ovarian atresia in cephalopods

Ovarian atresia is described for the first time in cephalopods. Detailed histological examination of ovaries of Loligo vulgaris reynaudii in various stages of maturity revealed atresia in primary, previtellogenic and vitellogenic oocytes. These were analysed separately. Previtellogenic and vitellogenic oocytes could be subdivided into five clear stages, whereas primary atretic oocytes are given a general description. Follicular atresia lowers the number of maturing and mature eggs in the ovary, so previous fecundity estimates for cephalopods may have been too high. To correct potential fecundity estimates for losses arising from atresia, it is necessary to estimate the duration of each atresia stage in relation to the total spawning period.

Treatment and histopathology of a congenital vitreous cyst

Objective This study aimed to evaluate the treatment efficacy of a congenital vitreous cyst and to examine the cyst histopathologically to determine its cellular makeup and possible origin. Study design The study design was a case report, including a clinicopathologic correlation. Intervention A 35-year-old woman with a known vitreous cyst since childhood became increasingly troubled by its symptoms. The cyst was treated initially with argon laser photocoagulation. Vitrectomy subsequently was performed because the deflated cyst remained near the visual axis. Histopathologic studies included light and electron microscopy; immunocytochemistry for actin and glial fibrillary acidic protein (GFAP); and enzyme histochemistry for carbonic anhydrase (CA). Results The cyst was composed of a single layer of heavily pigmented cells with a thick basement membrane along the internal borders of the cells. Ultrastructurally, the cells were connected with tight junctions, had microvillous processes at their apices, and contained numerous large melanosomes in various stages of maturity, including premelanosomes. Immunochemistry showed the cells were positive for actin but negative for GFAP. Enzyme histochemical staining for CA also was strongly positive. Conclusions The confinement of this cyst to the region of Cloquet’s canal, the presence of a Mittendorf’s dot, the cyst’s existence for many years, and the finding of pigment epithelial-type cells having immature melanosomes (a feature not seen after birth in normal pigment epithelium) lead the authors to believe that this cyst was a congenital remnant of the primary hyaloidal system. Because pigmented cells are not normally present in this part of the eye, the cyst was a choristoma of the primary hyaloidal system.

Nutritive value of silage made of whole barley crop harvested at various stages of maturity

Nutritive value of silage made of whole barley crop harvested at various stages of maturity

First Report of Powdery Mildew Caused by Oidium araliacearum on Ivy in California.

Powdery mildew was observed on English ivy (Hedera helix L.) in Berkeley, CA, in the spring of 1997. Fungal growth was ectophytic and amphigenous on leaves and petioles and caused slight reddening and buckling of leaves. The mycelium was white, effuse to dense, and had hyphal diameters of 3.5 to 6.9 μm. Appressoria were nipple-shaped to lobed, and sometimes were opposite. The foot cells of the conidiophores were cylindric, sometimes slightly flexuous, and were 18.5 to 30.0 × 6.9 to 9.2 μm in diameter. The foot cells were followed by 1 or 2 cells. When only one cell followed the foot cell, this cell was longer and slightly wider than the foot cell and measured 20.8 to 46.2 × 6.9 to 9.2 μm. When two cells followed the foot cell, these cells were of similar length to the foot cell, with the second cell usually shorter. Conidia were formed singly, were cylindric to slightly doliiform, and measured 32.0 to 44.0 × 11.5 to 19.0 μm. Fibrosin bodies were not observed. Conidia germinated at the ends and germ tubes terminated in lobed appressoria, placing this fungus in the Polygoni-type germination category (2). Cleistothecia were not observed. Based on these characters, the fungus was identified as Oidium araliacearum U. Braun & E. Oehrens B. A specimen was deposited with the University of California at Berkeley herbarium (accession number UC1713247). Pathogenicity was confirmed by gently pressing infected leaves onto leaves of various stages of maturity on ivy vines (3 to 4 vines per plant; 4 plants). Inoculated plants were kept in a moist chamber for 48 h, and then maintained in a greenhouse. Powdery mildew developed on inoculated plants, primarily on leaves of intermediate maturity, after 14 days, while uninoculated plants did not develop disease. Phyllactinia guttata is the only other powdery mildew recorded on English ivy (2). O. araliacearum differs from P. guttata in conidial shape (cylindric vs clavate), germination habit (end vs side of conidia), and asexual genus (Oidium vs Ovulariopsis) (2). Previous to this report, O. araliacearum was described only on Pseudopanax valdiviensis, another Araliaceae plant, in Chile (1). This is the first report of a powdery mildew disease of ivy in California, and the first report of Hedera helix as a host of O. araliacearum.

Zinnia Seed Harvest Time Affects Germination and Plant Growth

Seeds of `Kumamotonokagayaki'(Kk), `Goldenball' (Gb), and `Purple Gem' (PG) (Zinnia violacea Cav.) were harvested at various stages of maturity and subsequent seed and plant performance were evaluated. The largest increase in ovule or embryo length and width occurred from 0 to 10 days after pollination (DAP). The seed weight was unchanged after 23, 25, and 30 DAP for Kk, Gb, and PG, respectively. The pericarp color was completely green from seeds harvested 20 DAP, while the seeds harvested from 30 to 35 DAP contained a mixture of green and brown seeds. Pericarp color change from green to brown was not a reliable index to harvest seeds. The percentage germination increased from seeds harvested from 10 to 19 DAP for all cultivars. From 20 to 40 DAP, germination was unaffected and >90%, while the rate of germination as measured by days to visible germination decreased slightly. Seeds harvested 20 to 40 DAP produced plants with similar growth and quality characteristics. Considering a 20- to 30-day difference between the first and last floret to open in a capitulum, capitula should be harvested 50 days after anthesis for good seed quality and to prevent shattering.

Ethylene biosynthesis and respiration in strawberry fruit treated with diazocyclopentadiene and IAA

Diazocyclopentadiene (DACP), an inhibitor of ethylene action, was used to investigate the role of ethylene receptor(s) in regulating ethylene biosynthesis and respiration in strawberry fruit. DACP stimulated ethylene production of fruit at all stages of maturity. This stimulation was mainly due to an increase in ACC content in the tissue without significantly changing ACC oxidase activity. DACP did not induce any change in respiration in fruit at various stages of maturity except the early green stage (green I). We also investigated the possible interaction of DACP and IAA in ethylene production. Results indicated that all treatments increased ethylene production compared to the control although the absolute ethylene production differed in the order IAA plus DACP > only DACP > only IAA > control. IAA stimulated ethylene production without change of ACC oxidase activity at 1 day after treatment in strawberry fruit at pink stage. Results suggest that ethylene biosynthesis in nonclimacteric strawberry fruit at various stages of maturity may be regulated by ethylene receptor(s) with inhibition of ethylene production. DACP may release this inhibitory effect, and resulting in increasing ethylene production. Results also indicated that respiration may not be regulated by an ethylene receptor in strawberry fruit at most stages of maturity. DACP and IAA showed interaction in regulation of ethylene production which was caused by an increase in ACC content, not ACC oxidase activity.

Differences in Surface Color, Flesh Firmness, Physiological Activity, and Some Components of Loquat Fruits picked at Various Stages of Maturity

To study the compositional and physiological difference of 'Mogi' loquat fruits, the fruits harvested at different maturity stages were analyzed for surface color, flesh firmness, sugar content, acid content, phenolic compounds content, carotenoids content, re-spiration rate, and ethylene production. The index of maturity was 1 (green, small)7 (yellowish orange, harvest maturity) and 8 (slightly over ripe).1. Changes of surface color of loquat fruit expressed by Hunter color value indicated that the green color faded out and yellow color appeared over maturity stages 14, the reddish color appeared over the stages 58.2. Flesh firmness decreased between stage 4 and 5, but there was no detectable softening of the flesh afterwards to full ripe.3. Fructose, glucose and sucrose were the dominant sugars; sorbitol was the minor sugars. Sucrose content decreased from the stage 5 to 8, fructose as the dominant sugar at maturity stage 8.4. Malic acid was the dominant organic acid; citric, fumaric and succinic acids were the minor ones. Malic acid content decreased through fruit maturation, while citric acid content remained nearly constant.5. Phenolic compounds content and ratio of orthodiphenol to total phenolics increased during fruit maturation.6. β-Carotene was the dominant carotenoid in stage 2; cryptoxanthin became predominant in maturity stage 7. Cryptoxanthin was seemed to exist mainly as 4 esters.7. Respiration rate of loquat fruit decreased during maturation. Ethylene production of the fruit increased simultaneously with the decrease of green color and the appearance of reddish color.8. Our results indicated that stage 7 is the optimum harvest maturity.

Effects of an Enzyme Additive on Composition of Corn Silage Ensiled at Various Stages of Maturity

Corn forage at the milk, soft dough, and black layer stages of maturity (22, 28, and 44% DM, respectively) was treated with an enzyme additive at 1, 10, or 100 times the recommended dose and ensiled in laboratory silos at 26°C. By in vitro assay, the additive contained a full complement of cellulase and hemicellulase activities. The pH and temperature optima for cellulase and hemicellulase activities were 4.8 and 50°C, respectively. Regardless of dose, the additive had no effect on fermentation acids or nitrogenous compounds in silage at any maturity; however, high doses increased the glucose content of silage at the milk stage of maturity and increased ethanol content at the soft dough stage. Across maturities, addition of the enzyme additive resulted in a linear decrease in ADF, NDF, and hemicellulose content of corn silage but decreased the acid detergent lignin content of silage only at the milk and black layer stages of maturity. The enzyme additive had no consistent effect on in vitro NDF digestion.

Desiccation of alfalfa for seed production with diquat and glufosinate

Recommendations for desiccation of alfalfa do not clearly define the stage at which desiccants should be applied. To obtain this information, diquat and glufosinate were applied to alfalfa (Medicago sativa L) from 1991 to 1994 at various stages of maturity to determine the effect of desiccant and stage of maturity at desiccation on seed yield 1000-seed weight and seed germinability. Alfalfa seed yields, 1000-seed weights, percent germination and percent viable seed were similar after desiccation with diquat and glufosinate. Desiccation when 60–75% of the alfalfa seed pods were brown permitted maximum seed yields. Percent germination increased slightly in seeds that were exposed to weathering under normal conditions until all pods turned brown. Both desiccants adequately desiccated alfalfa for harvesting but desiccation with glufosinate took 2 or 3 d longer than diquat. Desiccants did not reduce alfalfa growth in the spring after application. Key words: Germination, yield, hard seed, seed weight, stage

Effect of carbon dioxide enrichment on physico-chemical and enzymatic changes in tomato fruits at various stages of maturity

The influence of CO 2 enrichment on fruit growth, firmness and colour, together with its effect on the concentrations of ascorbic acid, organic acids and sugars, and the activities of sucrose synthase (SS) (UDP glucose: D-fructose 2-glucosyltransferase, E. C. 2. 4. 1. 13) and sucrose phosphate synthase (SPS) (UDP glucose: D-fructose-6-phosphate 2-glucosyltransferase, E. C. 2. 4. 1. 14) were determined at various stages of maturity in fruits of tomato ( Lycopersicon esculentum Mill. cv. Momotaro). CO 2 enriched tomatoes had lower amounts of citric, malic and oxalic acids, and higher amounts of ascorbic acid, fructose, glucose and sucrose synthase activity than the control. Elevated CO 2 enhanced fruit growth and colouring during development. Citric acid was the primary organic acid followed by malic and oxalic acids. The concentration of organic acids (mg g −1 fresh weight) and of ascorbic acid (mg 100g −1 fresh weight) increased with the maturity of fruits; their maximum concentrations were found at the pink stage of ripening, but declined slightly at the red stage. The amount of reducing sugars (mg g −1 fresh weight) increased with the advancement of maturity, with fructose being the predominant sugar. The decrease in SS activity was accompanied by an increase in the concentrations of reducing sugars. There were no significant differences in fruit firmness, sucrose concentration and SPS activity between the treatments. The SPS activity did not change, but remained relatively constant throughout fruit development. The results also suggest that SS levels correlated positively with sucrose concentration but negatively with the concentration of reducing sugars.

In situ hybridization analysis for expression of myogenic regulatory factors in regenerating muscle of mdx mouse.

Precise temporal and spatial coordination of expression of the myogenic regulatory factors (MRF) plays a critical role in the development of skeletal muscle. Whether this pattern is recapitulated postnatally during regeneration of mature muscle after injury is not known. The aim of this study was to determine the cellular distribution of mRNA expression of the various myogenic regulatory factors (MyoD, Myogenin, Myf-5 and Myf-6) during regeneration in mature skeletal muscle. We used the mdx mouse, an animal model for Duchenne muscular dystrophy, which undergoes necrosis and vigorous regeneration of muscle fibers, as a natural model to study muscle fibers at various stages of maturity ranging from satellite cells to mature muscle fibers. In situ hybridization analysis revealed that MyoD expression was the most widespread and was expressed in satellite cells and small regenerating muscle fibers surrounding necrotic fibers. Myogenin, Myf5, and Myf6 were expressed weakly in some immature fibers and none of the MRF's could be detected in mature muscle. These findings, taken together with previous studies, suggests that the pattern of expression of the various MRF's in regenerating skeletal muscle differs from that in developing muscle in embryos and that MyoD may play a critical role in the initiation and progression of events which lead to regeneration in mature skeletal muscle.

Effects of Medium Composition on in vitro Germination of Embryos of Fraxinus excelsior at Different Stages of Development

Summary The developmental response of isolated embryos of Fraxinus excelsior at various stages of maturity and dormancy was observed on agar media of different compositions (the mineral-rich Murashige-Skoog medium, a mineral-poor medium composed for embryo culture and water agar in different combinations with sucrose and gibberellic acid (GA3)). Germination tests were conducted at five characteristic stages of seed development: embryo organogenesis completed, reserve deposition, seed maturation, embryo fully grown and embryo mature. The differences in the response to the various media were most pronounced at earlier stages of development, but they became insignificant when the embryo was mature.

The use of cell wall organic matter components and in vitro degradability characteristics to predict intake and digestibility of white clover for sheep

The relations of the laboratory measurement of cell wall organic matter (CWOM) components and of the in vitro degradability characteristics of CWOM with in vivo digestibility and voluntary intake for high quality white clover were investigated. The voluntary intake, apparent digestibility and apparent rumen retention time of CWOM of white clover harvested at various stages of maturity were measured in rumen-cannulated Merino wether sheep. The in vitro degradability characteristics of CWOM of these diets were also measured. This study has quantified strong predictive relations between structural fibre constituents or degradation parameters and both digestibility and intake for white clover. The CWOM, cellulose and hemicellulose contents and potential degradability of CWOM of the white clover predicted in vivo organic matter digestibility with good precision (r2 = 0.74, 0.67, 0.72 and 0.72 respectively). The voluntary intakes of organic matter and digestible organic matter of the white clover were strongly related to CWOM, cellulose and hemicellulose contents and to the rate of degradation of CWOM in the rumen and the fits of these relations were at least as good as those predicting organic matter digestibility. The predictive equations based on CWOM: OMD (g/kg) = 97.6-0.081 (� 0.012) CWOM OMI (g/kg) = 83-0.085 (� 0.018) CWOM DOMI (g/kg) = 71.4-0.098 (� 0.015) CWOM are recommended because of the ease of analysis of CWOM in the laboratory.

TNF-alpha inhibits the further development of committed progenitors while stimulating multipotential progenitors in mouse long-term bone marrow cultures.

Abstract We studied simultaneously the effect of TNF on both relatively primitive and more mature hematopoietic progenitors by using a modification of the mouse long-term bone marrow culture system of Dexter. Mycophenolic acid-treated long-term bone marrow cultures were charged with stromally depleted bone marrow cells along with 10 to 500 U/ml recombinant human TNF-alpha, and assayed each week for 5 wk for the presence of primitive (CFU-S and high proliferative potential colony-forming cell) and mature (CFU-C) colony-forming units. The results demonstrate that TNF-alpha has differential effects on hematopoiesis; it virtually eliminates CFU-C, significantly lowers high proliferative potential colony-forming cell (CFC) numbers and increases CFU-S numbers. This effect appears to be independent of CSF production in the cultures as shown by protein assays. Northern blot analyses showed no differences in expression of CSF genes or any expression of those encoding for IL-1, IL-3, or IL-6. These results, obtained in a long-term culture system that closely mimics in vivo bone marrow, demonstrate that many of the apparently contradictory effects of TNF observed in vitro occur concomitantly and are attributable to the presence of cells at various stages of maturity in the cultures. The data suggest a mechanism of this activity in which TNF is able to block the differentiation of primitive progenitors even as they are stimulated to proliferate.