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71.
Antonio J. Ferreira 《The Western journal of medicine》1961,94(6):369-377
The causes and the nature of the psychiatric disorder labeled schizophrenia remain vexingly obscure. Perhaps as an expression of a still extant body-mind controversy, most of the experiments and statements made toward an elucidation of the problem follow one or the other of two opposing postulations: (a) That its origin is genetico-organic; (b) that it is environmental. In a review of the outstanding “facts” for either argument, it is notable that they presuppose not only a difference in theoretical frameworks, but two radically distinct outlooks. This is reflected in therapy, a field in which organicists and environmentalists stand even further apart; the organicist, relying heavily on electroshock and drugs, hopes to counteract a hypothetical body malfunction, and the environmentalist, through psychotherapy, attempts to make it possible for the patient to disentangle his own conflicting feelings and reaction patterns.Between the two an eclectic position seems hardly tenable. For, in spite of voluminous research and speculation, it has not been possible to build a bridge between the two camps and integrate different outlooks which, at times, have brought psychiatry almost to the point of schism. 相似文献
72.
An algorithm to simulate DNA sequence evolution under a generalstochastic model, including as particular cases all the previouslyused schemes of nucleotide substitution, is described. The simulationis carried out on finite, variable length, DNA sequences througha strict stochastic process, according to the particular substitutionrates imposed by each scheme. Five FORTRAN programs, runningon an IBM PC and compatibles, carry out all the tasks neededfor the simulation. They are menu driven and interfaced to thesystem through a principal menu. All sequence data files usedand generated by the SDSE package conform to the standard GenBankdatabase format, thus allowing the use of any sequence retrievedfrom this databank, as well as the application of other packagesto analyse, manipulate or retrieve simulated sequences.
Received on August 23, 1988; accepted on November 15, 1988 相似文献
73.
Facchiano Angelo; Facchiano Antonio; Facchiano Francesco; Ragone Raffaele; Colonna Giovanni 《Bioinformatics (Oxford, England)》1989,5(4):299-303
A flexible package designed to study protein structure is described.The package is devoted to the analysis of protein sequencesby drawing structural profiles of specific structure-relatedamino acid parameters. An Aminoacidic Parameters Data Bank (CHAMP)containing 32 different series of physico-chemical parametersof amino acids is available. Sequences can be loaded from anyASCII format data bank or from keyboard. The program possessesa routine which enables easy updating of the protein data bankand CHAMP Data Bank. FAST reads statistical correlations betweentwo plots in order to identify structural similarities. Plotscan be printed, saved or used for correlation, comparison orgraph overlap by using common spreadsheets (e.g. Lotus 123).Plots can be smoothed by a running mean or a running median.The program also has a special featurea global flexibilityanalysis of proteins. The package runs on IBM or compatiblesand requires DOS 3.0 or later.
Received on June 20, 1989; accepted on August 2, 1989 相似文献
74.
75.
Sirlei D. Pereira Osvaldo Marinotti Antonio G. de Bianchi 《Archives of insect biochemistry and physiology》1989,11(4):245-255
During vitellogenesis in Musca domestica, a major hemolymph protein, in addition to vitellogenin, appears preferentially in females. This protein is synthesized by the adult fat bodies, secreted into the hemolymph, and is not taken up by the ovaries during vitellogenesis. We have designated this protein nonvitellogenic female protein (NVFP). It is composed of only one type of polypeptide (Mr=70,000) and occurs in two different forms. Synthesis of NVFP is induced by a protein diet, attaining maximum concentrations in females at the middle of the gonotrophic cycle. In males its maximum concentration never surpasses 10% of the concentration in females. The quantitative variation of the NVFP is cyclic and coincident with the gonotrophic cycles of Musca domestica. 相似文献
76.
Maria F. Fernández Antonio Cobos Lorenzo Hoz Dr. Pablo E. Hernández Bernabé Sanz 《Current microbiology》1989,18(2):113-117
Operon fusions to the promoter of either theproA,proB, orproC genes of the proline biosynthetic pathway were obtained by the use of the Mu d1(Ap,lac) bacteriophage. These fusions were further stabilized by transformation with plasmid pGW600 containing the wildtype Mu repressor gene or by transduction with phage pSG1. The level of -galactosidase in the fusion strains was not affected by the presence of exogenously addedl-proline or high concentrations of NaCl in the growth medium. A Tn5 insertion nearproBA increased -galactosidase expression 140- to 200-fold in strains carrying theproA-lac andproB-lac fusions, but the level of this enzyme was unaltered in strains carrying theproC-lac fusion. The Tn5 insertion increased intracellular proline concentrations 8- to 10-fold, suggesting that mechanisms other than allosteric inhibition may regulate proline biosynthesis, but did not confer osmotolerance to cells growing in a medium with a high concentration of salt. 相似文献
77.
78.
Roberto F. Nicosia Antonio Ottinetti 《In vitro cellular & developmental biology. Plant》1990,26(2):119-128
Summary Rings of rat aorta cultured in Matrigel, a reconstituted gel composed of basement membrane molecules, gave rise to three-dimensional
networks composed of solid cellular cords and occasional microvessels with slitlike lumina. Immunohistochemical and ultrastructural
studies showed that the solid cords were composed of endothelial sprouts surrounded by nonendothelial mesenchymal cells. The
angiogenic response of the aortic rings in Matrigel was compared to that obtained in interstitial collagen, fibrin, or plasma
clot. Morphometric analysis demonstrated that the mean luminal area of the microvascular sprouts and channels was significantly
smaller in Matrigel than in collagen, fibrin, or plasma clot. The percentage of patent microvessels in Matrigel was also markedly
reduced. Autoradiographic studies of3H-thymidine-labeled cultures showed reduced DNA synthesis by developing microvessels in Matrigel. The overall number of solid
endothelial cords and microvessels was lower in Matrigel than in fibrin or plasma clot. A mixed cell population isolated from
Matrigel cultures formed a monolayer in collagen or fibrin-coated dishes but rapidly reorganized into a polygonal network
when plated on Matrigel. The observation that gels composed of basement membrane molecules modulate the canalization, proliferation,
and organization into networks of vasoformative endothelial cells in three-dimensional cultures supports the hypothesis that
the basement membrane is a potent regulator of microvascular growth and morphogenesis.
This work was supported by grants from the W. W. Smith Charitable Trust and grants CA14137 and HL43392 from the National Institutes
of Health, Bethesda, MD. 相似文献
79.
80.
In unispecific plant stands, the logarithm of mean individual weight (w) depends on the logarithm of density (d) by the -3/4 power law (a slope of -1.5 and an intercept ranging from 2.3 to 5.0). The analysis of the w and d relationships in whole cohorts of two seaweed species from the Strait of Gibraltar shows deviations from the canonical equation. The kelp Phyllariopsis purpurascens (C. Agardh) Henry et South (Phaeophyta) growing at a 30-m depth has the lowest intercept value (0.6) recorded for any plant species and a slope not significantly different from -1.5. The slope value is in accordance with those found in species whose growth is not stopped by reproduction. Irradiance under a single layer of blades was lower than the photosynthetic light compensation point, and this could be due to overdispersion of the shoots and, in consequence, to the low intercept value of the self-thinning equation. The w to d relationships in Asparagopsis armata Harvey (Rhodophyta) show two different components: no dependence between these two variables (slope not significantly different from 0) at densities < 500 shoots·m?2, and a slope more negative (-2.1) than proposed by the -3/2 power law at densities > 500 shoots·m?2. The pattern at high densities could be due to intraspecific competition for light, whereas the slope ~0 at low densities could be related to inhibition of growth by reproduction (cystocarp and carpospore production). Therefore, rather than being considered exceptional, we suggest that a gradient of variability could be expected in the dependence of w on d when specific growth patterns and reproduction are considered. 相似文献