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Summary: After recalling the main points of the general QCD parametrization —GP— we discuss systematically its application to the properties of the lowest baryon and meson families. We show how the hierarchy of parameters in the GP emerges clearly from the experimental data. This fact explains (among other things) why some simple models of hadrons work reasonably well; it also clarifies the relationship between current and constituent quarks. The specific hadron properties to be discussed with the GP appear from the list of sections below. In particular, sects. 1, 2 and 3 show: 1) how the general QCD parametrization is derived exactly from QCD, 2) what are the "parameters" and 3) how their order of magnitude decreases with increasing complexity of the terms being considered (the "hierarchy"). [ABSTRACT FROM AUTHOR]

The effect of colony density on the dimorphic switch was determined in natural strains of Saccharomyces cerevisiae. In some strains invasiveness and pseudohyphal (PH) growth were highly sensitive to colony density; moreover, strains constitutively able to invade the substrate with PH formation positively influenced the invasiveness but not the PH growth of a different strain less prone to the dimorphic switch. [ABSTRACT FROM AUTHOR]

The frequency of reversion in a histidine-requiring mutant of Saccharomyces cerevisiae increases about ten-fold in stationary cells during histidine starvation. Histidine starvation enhances a similar frequency of reversion in a tryptophan-requiring mutant. Starvation, therefore, enhances mutation frequencies in a non-adaptive manner. The base analogue 6-N-hydroxylaminopurine (HAP) added prior to plating on medium with limited histidine strongly increases reversion of the histidine mutant. HAP-induced reversion increases further in stationary starving cells with the same kinetics as that which increases spontaneous reversion. Adding HAP to the stationary starving cells does not produce any effect. [ABSTRACT FROM AUTHOR]

A quasi no flavor breaking theorem, derived from QCD for a class of hadronic states, is used to show that the ratio of ϱγ to ωγ coupling-for ideal ω-ϕ mixing-is almost (to a part in 10) unaffected by flavor breaking, and, therefore, equal to 3. On the other hand the ratio of ϱγ to ϕγ coupling, (not governed by the theorem) must differ, due to flavor breaking, from the unbroken SU value $$(3/\sqrt 2 )$$ . The data are consistent with these predictions. As a byproduct we determine the small deviation δ≈−3° of the mixing vector angle from the ideal value (35.3), including its sign, that turns out to be negative (opposite to the positive traditional value based on an approximate mass analysis). The derivation of the quasi no flavor breaking theorem is based, as shown in a previous paper, on the method of general parametrization. It exploits the simple SU (flavor) structure of the QCD Lagrangian. We note some consequences of the theorem relevant to the equivalence to QCD of certain effective Lagrangian theories and models. [ABSTRACT FROM AUTHOR]

Using the parametrization method we prove that in QCD the magnetic moments M of the four Δ′s are almost proportional to their charges Q ('almost' means neglecting a term O(1/300)); that is, writing M= kQ+β, we have β/ k≅3·10. Moreover the value of the coefficient k is not affected by flavor breaking. These properties are, we show, a particular case of a more general result: In QCD the flavor properties of the lowest nonstrange baryonic states valid in unbroken SU (flavor) hold 'almost' exactly. Finally we compare these results with those obtained by Lagrangian models with 0 meson fields treated as independent degrees of freedom; the case of the cloudy bag model is illustrated in some detail. [ABSTRACT FROM AUTHOR]

Most of the available data in lower eukaryotes are consistent with the idea that base analogs-induced mutagenesis is due to the mis-pairing properties of these compounds, which, in turn, is due to a shift in the tautomeric equilibrium of the molecule. A tautomeric shift may in fact lead to mismatches which, at least in Escherichia coli, can be repaired by genes involved in the post-replicative mismatch repair whose activity is necessary to control spontaneous mutagenesis. In filamentous fungi, such as Aspergillus nidulans, nothing is known about the repair of base pairing mistakes after base analogs treatment. For this reason, we have decided to screen UV-sensitive Aspergillus nidulans mutants for their mutagenic response to 6-N-hydroxylaminopurine (HAP). We have shown that three mutations (uvsB, uvsC and uvsE), which enhance the UV-sensitivity of germinating conidia, cause a lower mutagenic response to HAP. On the other hand, the uvsH mutation, has no effect on HAP-induced mutagenesis. [ABSTRACT FROM AUTHOR]

Since dicarboxylic acids are competitive inhibitors of tyrosinase, and effective in treatment of hyperpigmentary disorders, such as chloasma and lentigo maligna, probably due to a cytotoxic effect on abnormal melanocytes, it is of interest to examine their effect on normal melanocytes in tissue culture. Azelaic or dodecandioic acids were added (150–200 μg/ml) to dispersed cultures of epidermal cells, and melanocytcs were examined by electron microscopy after 7, 10, 15, 20 and 30 days. Apart from a stimulation of melanogencsis, the presence of dicarboxylic acids in the culture medium caused no detectable damage to melanocytcs, nor did they prevent growth of a second generation of cells. [ABSTRACT FROM AUTHOR]

Haploid and diploid strains of Aspergillus nidulans have been repeatedly treated with the strong mutagen 6-N-hydroxylaminopurine (HAP) which causes only base substitutions. An enormous amount of variability may be rapidly accumulated in haploid or diploid strains of A. nidulans. In particular, in the diploids the analysis of the results shows that after 12 cycles of treatment the conidia differ from each other for about ten recessive lethals and therefore probably for several hundreds of mutations. The viability of the heterozygous multiply mutant diploids is not appreciably different from that of untreated controls. In the diploid strains the accumulated variability was very high. The treatment of a haploid strain during vegetative growth also caused a strong accumulation of mutations, even though deleterious, because they can be maintained in the heterokaryotic condition. [ABSTRACT FROM AUTHOR]

An unexpectedly large number of p-fluorophenylalanine (FPA)-resistant mutants have been recovered after UV-irradiation of wild type diploid conidia of Aspergillus nidulans. At least five different classes of mutants, possibly corresponding to five different loci, have been identified. Two of them may be the dominant loci which have already been described but the others (a minimum of three loci) are completely different. Mutations in these loci confer high level FPA resistance in the heterozygous diploids, being lethal in the haploids; one mutation has been preliminarily mapped to chromosome I and another to chromosome III. [ABSTRACT FROM AUTHOR]

The growth-promoting effects of nurse cells of carrot, tomato, potato, maize, bean, carnation and two species of tobacco were studied on carrot, tomato, tobacco and potato cells plated at low densities. In an area immediately below the nurse cells the plating efficiency was very high and found to be independent of cell density. In an area outside the nurse cells, in some cases, the plating efficiency tended to be much higher in combinations with cells from a heterologous source as compared with those from a homologous source. Moreover, in the same area with some combinations the plating efficiency decreased when cell density was lowered, while with other combinations this phenomenon did not occur. This decrease was independent of the absolute value of plating efficiency. In experiments in which the concentration of conditioning factors was presumably changed, no significant difference in the plating efficiency was noticed. We therefore suggest that different plating efficiencies observed with heterologous nurse cells were not due to a higher level of conditioning factors, but rather to the production of different types of conditioning factors that are presumably degraded with different efficiency. [ABSTRACT FROM AUTHOR]

An epidemiological study was conducted in the city of Rome and the incidence of malignant melanoma was determined retrospectively for the years 1970-9. All patients had legal residence in Rome and a histological diagnosis of melanoma during that period; only cases of malignant melanoma of the skin (ICD 172, 8th revision) were considered. A total of 17 public and 82 private hospitals were involved in the study with 11 081 and 6127 hospital beds respectively. All the hospitals in the study had one of the following therapeutic and diagnostic facilities: internal medicine, dermatology, oncology, radiology, surgery, plastic surgery, histopathology. Analyses of incidence are based on 500 cases, 237 males and 263 females, collected in the period 1970-9. The data indicate a positive time trend in incidence; the average annual increase is 0.27 cases/year per 100 000. The data show that in a Mediterranean and Latin country such as Italy the incidence of melanoma presents the same ascending trend as that of other Caucasian countries, whether European or not, the slope of the curves is similar for both sexes. The distribution of the primary site for both sexes is closely parallel to that described for all Caucasian populations, the lower limbs being more affected in females and the trunk in males. [ABSTRACT FROM AUTHOR]

An epidemiological study was conducted in the city of Rome and the incidence of malignant melanoma was determined retrospectively for the years 1970-9. All patients had legal residence in Rome and a histological diagnosis of melanoma during that period; only cases of malignant melanoma of the skin (ICD 172, 8th revision) were considered. A total of 17 public and 82 private hospitals were involved in the study with 11 081 and 6127 hospital beds respectively. All the hospitals in the study had one of the following therapeutic and diagnostic facilities: internal medicine, dermatology, oncology, radiology, surgery, plastic surgery, histopathology. Analyses of incidence are based on 500 cases, 237 males and 263 females, collected in the period 1970-9. The data indicate a positive time trend in incidence; the average annual increase is 0.27 cases/year per 100 000. The data show that in a Mediterranean and Latin country such as Italy the incidence of melanoma presents the same ascending trend as that of other Caucasian countries, whether European or not, the slope of the curves is similar for both sexes. The distribution of the primary site for both sexes is closely parallel to that described for all Caucasian populations, the lower limbs being more affected in females and the trunk in males. [ABSTRACT FROM PUBLISHER]

Copyright of II Nuovo Cimento is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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Copyright of Experientia is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The uvsC gene of Aspergillus nidulans is a homolog of the RAD51 gene of Saccharomyces cerevisiae. However, with respect to its effects on UV mutagenesis, it differs from the yeast gene, since it seems to be required for UV mutagenesis; however, this conclusion is based only on data from resting conidia. To further clarify the functional role of the uvsC gene, we tested the UV mutability of strains bearing a uvsC mutation in resting as well as in germinating conidia, by the p-fluoro-phenyl-alanine resistance test. We also evaluated the mutability of the uvsE mutant which belongs to the same epistatic group. Our results show that the uvsC and uvsE genes do not have a significant role in the mutagenic UV-repair pathway. [ABSTRACT FROM AUTHOR]

On exposing to the air, in contact with Pd or Ni, heavily deuterated samples of TiFe or of LaNi, the samples may, occasionally, ignite becoming red hot. This supports the conjecture that the release in the Fleischmann-Pons cell is due to the ignition, in some cases, of the deuterium absorbed in palladium (2D+O→2DO) when the strongly deuterated Pd electrode is partially exposed to the air. [ABSTRACT FROM AUTHOR]

In this paper we describe a simple method to improve the plating efficiency in plant cell cultures. Two-stage plating is used; in the first stage the cells are inoculated at high density in 0.2% agarized culture medium for ten days to facilitate growth; under this condition, each cell produces a single micro-colony trapped in the agar network. In the second stage the colonies are plated at different densities in 1% agarized medium. These colonies are self-sufficient and able to improve the cell growth by conditioning the medium. [ABSTRACT FROM AUTHOR]

The article focuses on the effect of dicarboxylic acids on normal human melanocytes in culture. Since dicarboxylic acids are competitive inhibitors of tyrosinase, and effective in treatment of hyperpigmentary disorders, probably due to cytotoxic effect on abnormal melanocytes, it is of interest to examine their effect on normal melanocytes in culture. Dicarboxylic acids have an initial stimulatory effect on melanocytes of the original culture generation and that this may result in destruction of melanosomes.

Copyright of Experientia is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experientia is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experientia is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)