5,238 research outputs found
Glasgow time signals
From 1859 to 1864, both visual and audio one oâclock time signals operated in Glasgow. Although the University carried a remit to provide the cityâs time, following convoluted processes of establishment, a local chronometer-maker operated a time ball for 4 years. Towards the end of the period, time guns were triggered by telegraph from the Royal Observatory Edinburgh. Both exercises caused aggravation for the University. For the ball, the Professor of Astronomy, John Pringle Nichol, failed to convince the City Council that the âdropâ control should originate from the Universityâs Observatory. For the guns, Robert Grant, the newly appointed Astronomy Chair holder, was aggrieved by the Astronomer Royal for Scotland, Piazzi Smyth, appearing to operate above his station. Rather than having only a once per day reference, both projects were abandoned as the University laid a dedicated telegraph cable from its observatory to control many public clocks and additional clocks with large sweep fingers indicating exact time to the second
Price stability and the Swedish monetary experiment
An examination of the feasibility and appropriateness of establishing a direct, price-index target as the primary objective of U.S. monetary policy, with particular emphasis on the Swedish Riksbank's experiment with such an approach during the 1930s.Sweden ; Monetary policy - Sweden
Does Drinking Really Decrease in Bad Times?
This paper investigates the relationship between macroeconomic conditions, alcohol use, and drinking problems using individual-level data from the 1987-1999 years of the Behavioral Risk Factor Surveillance System. We confirm the procyclical variation in overall drinking identified in previous research using aggregate sales data and show that this largely results from changes in consumption among existing drinkers, rather than movements into or out of drinking. Moreover, the decrease in alcohol use occurring during bad economic times is concentrated among heavy consumers, with light drinking actually increasing in these periods. We find no evidence that the decline in overall drinking masks a rise in alcohol use for persons becoming unemployed during contractions, suggesting that any stress-induced increases in consumption are more than offset by reductions resulting from changes in economic factors such as lower incomes.
âWildcats
William Black, a native of Northeastern Pennsylvania, is completing an MFA at the University of Alabama. Wildcats is his first published story
Inheritance of resistance to Phytophthora infestans (Mont.) de Bary in hybrid derivatives of Solanum demissum Lindl
1. The common strain and nine specialised strains of
Phytophthora infestens were employed in testing seedlings
and seedling progenies, obtained from four different breeding
systems, for resistance to the disease.2. The resistance exhibited by S. demissum (CPC 2127) and
seedlings bred from it is due primarily to the hypersensitive
condition of the protoplasm. This condition is manifested
in the presence of one or more major resistance genes, of
which four have been identified, viz. Râ, Râ, Râ and Râ.3. Each major gene confers resistance to the common strain
and to a particular group of specialised strains of the parasite.
The genes are inherited independently in simple
Mendelian fashion.4. A series of minor genes, associated with morphological
and physiological characters of the plant, modify the phenotypic
expression of the major gene system, and so determine
the degree of susceptibility in susceptible phenotypes and
the extent of necrosis in resistant ones.5. In the early generations of S. demissum-S. tuberosum
hybrids, the irregularity of chromosome behaviour and the
presence of unpaired chromosomes caused the ratios of
resistants resistants to susceptibles to vary widely from standard
Mendelian ratios.6. In certain progenies, particularly those obtained by
crossing S. tuberosum plants with resistant hybrid derivatives
of S. demissum, deviations from standard Mendelian ratios
were consistent in their trend, and appeared to be due to some
relationship between genes affecting disease resistance and
incompatibility genes.7. In certain parent seedlings with duplicate genes,
derived from self- fertilised plants or from recombination
crosses, partial auto-syndesis resulted in an excess of
resistant segregates in the progenies.B. The interrelationships of ten strains of blight (Phytophthora
infestans) and four major genes Râ, Râ, Râ and Râ
controlling resistance to the disease in the potato are
examined.9. Since dominance of the genes is complete the maximum
number of phenotypic reactions which can be distinguished is
sixteen. This series represents the complete range of
differential hosts for the material in question and is
capable of distinguishing sixteen different strains of the
parasite.10. The reactions exhibited by the series form a concise
statement statement of the various relationships and provide the
necessary groundwork for the systematic classification of
strains. The classification will afford a basis for the
calculation of segregation- ratios to be expected from the
mating of any pair of genotypes when infected with any strain
or group of strains of the parasite.11. Each specialised strain, being adapted to a particular
Solanum genotype, is more prolific on it than on any other.
This genotype is regarded as the natural host of the strain.12. Specialised strains differ in their effect upon varieties
of S. tuberosum: Those with the widest host range
being least virulent. Also, they are less prolific and
cause less damage than the common strain.13. The exact mode of origin of strains is not clear but
mutation appears to play a significant part.14. Specialisation appears to progress in stages in certain
directions determined by the genetic constitution of the
various hosts. Examples of three progressive stages of
specialisation are apparent in the material reported on here.
If the fourth stage should be reached, the resulting strain
will be capable of attacking all sixteen genotypes.15. It is suggested that strains should be classified
according to the genetical constitution of their natural
hosts and that each should be known by the numeral pertaining
to the genes in question
Genetical studies in Solanum tuberosum L.
At the Scottish Plant Breeding Station, a schelu2 for the breeding of potatoes, Solarium tuberuum L. with a view tc the production of new varieties of economic value is in operation. This paper consists of observations upon a number of pro- blems undertaken by the writer, who has been Assis- tant in charge of potato breeding work since 1926. Cultivated varieties of S. tuberosum L. both named and unnamed have been employed in connection with the major investigations and several wild species of tuber-bearing Solanaceae have been introduced in other experiments.The experimentation to be discussed has been made for genetical study and for agricultural application. The observations related firstly to the mode of inheritance of characters affecting breeding work, namely flowering tendency and self sterility; and, secondly to the mode of inheritance of characters of agricultural importance, namely tuber skin colour, tuber shape and resistance to wart disease (S nch trium endobioticum Schilb.
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