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61.
Summary
Chamaedorea bartlingiana is a dioecious palm that grows in the cloud forest understories of the Venezuelan Andes. Age and sexual differences in phenology and reproductive patterns were studied in labelled individuals of all age categories. This species has long-lived leaves and low leaf production, both characteristic of understory plants. Growth rates are lower in juveniles than in adults and in females than in males, as in other palms. Male and female individuals show different reproductive patterns. Male inflorescences are always produced at the same rate and the probability of surviving until anthesis is constant. Females produce reproductive buds at the same rate as males, but these buds have a 35% probability of becoming a ripe infrutescence if the plant has infrutescences already growing, and 70% if it does not. This pattern and the slow growth of inflorescences (1 year for males from bud to flowers, 2 years for females from bud to ripe fruits) cause a pluriannual reproductive pattern at the population level. Field germination does not follow this pattern, but shows one annual peak probably related to environmental conditions. 相似文献
62.
Manuel Rey Teresa Fernández Victoria González Roberto Rodriguez 《In vitro cellular & developmental biology. Plant》1992,28(3):148-152
Summary A profitable system for the establishment of morphogenic callus cultures and indirect shoot induction and development was
accomplished from nodal shoot segments obtained from adult and micropropagated plants of kiwifruit (Actinidia deliciosa [Chev.] Liang and Ferguson, var.deliciosa) cv. “Hayward”. The effects of medium composition, cytokinin levels, dilution of salts, and type of callus derived from the
cultured primary explants were studied. Medium composition as well as type of callus greatly affected organogenic responses. 相似文献
63.
Teresa M. Szopa 《Journal of insect physiology》1981,27(7):441-446
Allatectomy of adult female Schistocerca gregaria prevents the normal development of the accessory reproductive glands and no secretion is produced. Development of the glands can be restored by the administration of synthetic juvenile hormone and the response is dose-dependent. A continuous supply of hormone is required for maintenance of secretory activity. In the normal developmental sequence the total protein content of the glands remains constant until the time at which vitellogenesis occurs in the terminal oöcytes. As maturation proceeds there is a linear increase in protein content of the glands. The initial increase occurs as a result of cellular changes in the glands and is then followed by an increase due to an accumulation of secretion in the lumina. 相似文献
64.
Gary A. Griess Ph.D. Seymour Zigman Ph.D. Teresa Yulo 《Molecular and cellular biochemistry》1976,12(1):9-14
Summary Variations in size and charge of calf lens proteins, particularly gamma crystallins, were studied by polyacrylamide gel electrophoresis. Exposure of gamma crystallins to near-UV light in the presence of L-tryptophan produces species of higher electrophoretic mobility and higher retardation. Treatment with urea and sulfonation also produced changes in the retardation co-efficient. The increase of retardation co-efficient of gamma crystallin is interpreted to be a result of conformational changes. Gamma crystallins are particularly sensitive to photo-modification, and this process may be associated with age-related changes in the lens.Supported by research grants from the U.S.P.H.S. EY #00459, a FIGHT-FOR-SIGHT Postdoctoral Research Fellowship (FIGHT-FOR-SIGHT, INC., N.Y.C.) and The Rochester Eye and Human Parts Bank, Inc. 相似文献
65.
66.
67.
Jon Cacicedo Elisa Gmez Inhiesto Maria Teresa Acaiturri Ayesta Iker Ustarroz Dirk Rades 《Reports of Practical Oncology and Radiotherapy》2022,27(4):610
BackgroundThe aim of this study was to evaluate the results and economic costs of using volumetric modulated arc therapy (VMAT) (5 fr × 5 Gy), compared with other conventional 3D radiotherapy schemes such as “5 × 4 Gy” and “10 × 3 Gy”.Materials and methodsThe data about the direct costs for the public health system was obtained from the Economic Information “Management per Patient” System available at the Integrated Health Organization Ezkerraldea Enkarterri Cruces. It is a model of real costs per patient which uses a bottom-up methodology which connects all sources of information generated in clinical practice, integrating healthcare information with economic information. This system presents the real cost per individualized patient, and shows the traceability of all clinical care. The costs of “typical patients” requiring hospital admission were identified for each of the three radiotherapy schemes based on the clinical activity and the material and human resources that were used.ResultsThe 5 × 5 Gy scheme has a cost of EUR 4,801.48, which is 1.64% higher (EUR 77) than the “5 × 4 Gy” scheme (EUR 4,724.05). The “10 × 3 Gy” scheme has a cost of EUR 8,394.61, which is 74.8% higher (EUR 3,593) than the “5 × 5 Gy” scheme. The main cost factor in the “10 × 3 Gy” scheme is hospitalization, since patients are at hospital for 2 weeks compared with 1 week in the “5 × 5 Gy” scheme.ConclusionsThe cost per patient of the VMAT “5 × 5 Gy” radiotherapy scheme is notably lower than that of the “10 × 3 Gy” scheme (conventional 3D radiotherapy), with the advantage of being administered in half the time. In relation to the scheme with 5 Gy × 4 sessions, the cost is similar to that of the “5 × 5 Gy” scheme. 相似文献
68.
Permeabilization induced by lacticin 3147, lactococcins A, B and M, enterocin AS-48 and nisin, bacteriocins described as cell membrane-pore forming and lytic agents, enhanced in all cases aldehyde formation by Lactococcus lactis IFPL730. Nevertheless, the conversion of isoleucine into 2-methylbutyraldehyde depended not only on the degree of permeabilization but also on the bacteriocin that caused the cell membrane damage. The highest values of 2-methylbutyraldehyde corresponded to cell suspensions containing lacticin 3147 and lactococcins, treatments that provoked further lysis in addition to induced permeabilization. 相似文献
69.
Graça Soveral Catarina Prista Teresa F. Moura Maria C. Loureiro‐Dias 《Biology of the cell / under the auspices of the European Cell Biology Organization》2011,103(1):35-54
In yeast, the presence of orthodox aquaporins has been first recognized in Saccharomyces cerevisiae, in which two genes (AQY1 and AQY2) were shown to be related to mammal and plant water channels. The present review summarizes the putative orthodox aquaporin protein sequences found in available genomes of yeast and filamentous fungi. Among the 28 yeast genomes sequenced, most species present only one orthodox aquaporin, and no aquaporins were found in eight yeast species. Alignment of amino acid sequences reveals a very diverse group. Similarity values vary from 99% among species within the Saccharomyces genus to 34% between ScAqy1 and the aquaporin from Debaryomyces hansenii. All of the fungal aquaporins possess the known characteristic sequences, and residues involved in the water channel pore are highly conserved. Advances in the establishment of the structure are reviewed in relation to the mechanisms of selectivity, conductance and gating. In particular, the involvement of the protein cytosolic N‐terminus as a channel blocker preventing water flow is addressed. Methodologies used in the evaluation of aquaporin activity frequently involve the measurement of fast volume changes. Particular attention is paid to data analysis to obtain accurate membrane water permeability parameters. Although the presence of aquaporins clearly enhances membrane water permeability, the relevance of these ubiquitous water channels in yeast performance remains obscure. 相似文献
70.
Ferrer E Sánchez J Milano A Alvarez S La Rosa R Lares M González LM Cortéz MM Dávila I Harrison LJ Parkhouse RM Gárate T 《Experimental parasitology》2012,130(1):78-85
To study diagnostic epitopes within the Taenia solium 8 kDa antigen family, six overlapping synthetic peptides from an 8 kDa family member (Ts8B2) were synthesized and evaluated by ELISA and MABA with sera from patients with neurocysticercosis (NCC), from infected pigs and from rabbits immunized with recombinant Ts8B2 protein. The pre-immune rabbit sera and the Ts8B2 recombinant protein served as negative and positive controls, respectively. A similar analysis was done with the already described antigenic peptides from another member of the 8 kDa family, highly similar to Ts8B2, the CyDA antigen. Surprisingly, neither the Ts8B2 peptides nor the CyDA peptides were recognized by infected human and porcine sera. However, the entire Ts8B2 recombinant, as well as amino and carboxy-terminal halves were recognized by the positive serum samples. The observed lack of recognition of linear Ts8B2 peptides suggests that the principal serological response to the Ts8B2 family is focused on conformational epitopes in contrast to the previously observed antigenicity of the CyDA peptides. This differential antigenicity of 8 kDa family peptides could be related with parasite antigenic variability. The fact that rabbits experimentally immunized with Ts8B2 did make anti-peptide antibodies to peptides Ts8B2-6 and CyDA-6, located in the carboxy-terminal region demonstrated that the Ts8B2 peptides are not intrinsically non-immunogenic. 相似文献