Search

This article provides a historical account of "Seebeck" stamps, which were postage stamps produced by Nicholas F. Seebeck and his company, the Hamilton Bank Note Co., in the late 19th century. Seebeck made agreements with the governments of Salvador, Honduras, Nicaragua, and Ecuador to supply postage stamps and postal stationery for a period of ten years in exchange for certain benefits. However, these stamps became highly unpopular among stamp collectors due to the ability to reprint them indefinitely, leading to a decline in their value. The contracts eventually ended, and today, these stamps are considered an interesting study and can be difficult to obtain in good condition. The given text appears to be a list of various stamps and their prices. It includes different sets such as Set 69.00, 3139-40 Pacific 97, 3209-10 Trans-Mississippi, and others. The prices range from $3.50 to $24.95. The text also mentions a minimum order of $10 and additional charges for postage and insurance. The contact information for placing an order is provided at the end. [Extracted from the article]

Establishment of Myxobolus cerebralis(Mc) resulted in declines of wild Rainbow Trout Oncorhynchus mykisspopulations in streams across Colorado during the 1990s. However, the risk for establishment and spread of this parasite into high-elevation habitats occupied by native Cutthroat Trout O. clarkiiwas unknown. Beginning in 2003, tubificid worms were collected from all major drainages where Cutthroat Trout were endemic and were assayed by quantitative PCR to determine the occurrence and distribution of the various lineages of Tubifex tubifex(Tt) oligochaetes. Over a 5-year period, 40 groups of Ttoligochaetes collected from 27 streams, 3 natural lakes, 2 private ponds, and a reservoir were evaluated for their relative susceptibility to Mc. Exposure groups were drawn from populations of pure lineage III Tt, mixed-lineage populations where one or more of the highly resistant (lineage I) or nonsusceptible lineages (V or VI) were the dominant oligochaete and susceptible lineage III worms were the subdominant worm, or pure lineage VI Tt. Experimental replicates of 250 oligochaetes were exposed to 50 Mcmyxospores per worm. The parasite amplification ratio (total triactinomyxons [TAMs] produced / total myxospore exposure) was very high among all pure lineage III Colorado exposure groups, averaging 363 compared with 8.24 among the mixed-lineage exposure groups. Lineage III oligochaetes from Mt. Whitney Hatchery in California, which served as the laboratory standard for comparative purposes, had an average parasite amplification ratio of 933 among 10 exposed replicates over a 5-year period. Lineage I oligochaetes were highly resistant to infection and did not produce any TAMs. Lineages V and VI Ttdid not become infected and did not produce any TAMs. These results suggest that the risk of establishment of Mcis high for aquatic habitats in Colorado where Cutthroat Trout and lineage III Ttare sympatric. Received April 19, 2013; accepted November 4, 2013

The spectral characteristics of dextran, labeled with fluorescein, depend upon pH. We have loaded the lysosomes of mouse peritoneal macrophages with this fluorescence probe and used it to measure the intralysosomal pH under various conditions. The pH of the medium has no effect on the intralysosomal pH. Weakly basic substances in the medium cause a concentration-dependent increase in the intralysosomal pH. However, the concentration of base necessary to produce a significant change in the intralysosomal pH varies over a wide range for different bases. The active form of the base is the neutral, unprotonated form. Although most of these weak bases cause an increase in the volume of the lysosomes, increase in lysosomal volume itself causes only a minor perturbation of the intralysosomal pH. This was demonstrated in cells whose lysosomes were loaded with sucrose, and in cells vacuolated as a demonstrated in cells whose lysosomes were loaded with sucrose, and in cells vacuolated as a consequence of exposure to concanavalin A. The results of these studies are interpreted in terms of energy-dependent lysosomal acidification and leakage of protons out of the lysosomes in the form of protonated weak bases.

With few exceptions, weakly basic compounds that are sufficiently lipophilic in their neutral forms and sufficiently hydrophilic in their protonated forms accumulate in lysosomes. When the concentration within the lysosomes becomes sufficiently high, osmotic swelling occurs. The cells than take on a vacuolated appearance. The concentrations at which different weak bases cause lysosomal vacuolation vary over almost three orders of magnitude. For any particular weak base, it is the concentration of the neutral form that determines the extent of uptake and the degree of vacuolation. Chloroquine is anomalous in that concentrations greater than approximately 30 microM cause less uptake and less vacuolation than do lower concentrations.

A quantitative method is described for the measurement of intralysosomal pH in living cells. Fluorescein isothiocyanate-labeled dextran (FD) is endocytized and accumulates in lysosomes where it remains without apparent degradation. The fluorescence spectrum of this compound changes with pH in the range 4-7 and is not seriously affected by FD concentration, ionic strength, or protein concentration. Living cells on coverslips are mounted in a spectrofluorometer cell and can be perfused with various media. The normal pH inside macrophage lysosomes seems to be 4.7-4.8, although it can drop transiently as low as 4.5. Exposure of the cells to various weak bases and to acidic potassium ionophores causes the pH to increase. The changes in pH are much more rapid than is the intralysosomal accumulation of the weak bases. Inhibitors of glycolysis (2-deoxyglucose) and of oxidative phosphorylation (cyanide or azide) added together, but not separately, cause the intralysosomal pH to increase. These results provide evidence for the existence of an active proton accumulation mechanism in the lysosomal membrane and support the theory of lysosomal accumulation of weak bases by proton trapping.

Basic substances and acidic ionophores that increase the lysosomal pH in cultured macrophages (Ohkuma, S., and B. Poole, 1978, Proc. Natl. Acad. Sci. USA., 75:3327-3331; Poole, B., and S. Ohkuma, 1981, J. Cell Biol., 90:665-669) inhibited the digestion of heat-denatured acetylated bovine serum albumin (BSA) taken up by the cells. For several substances, the shift in pH sufficed to explain the inhibition of proteolysis. Additional effects, presumably on enzyme activities, have to be postulated for tributylamine, amantadine, and chloroquine. Sodium fluoride (10 mM) had no significant effect on the breakdown of BSA by macrophages. The breakdown of endogenous macrophage proteins, whether short lived or long lived, was inhibited approximately 40% by 10 mM NaF and 30%, or sometimes less in the case of long-lived proteins, by 100 microM chloroquine. When the cells were supplied with BSA, a mixture of cell proteins, or even inert endocytosible materials, the breakdown of endogenous long-lived proteins and the inhibitory effect of chloroquine on this process were selectively reduced. Inhibition of endocytosis by cytochalasins B or D did not affect the chloroquine-sensitive breakdown of endogenous proteins, indicating that the proteins degraded by this process were truly endogenous and not taken in from the outside by cellular cannibalism. On the other hand, when macrophage proteins were supplied extracellularly, their breakdown occurred at the same rate for short-lived and long-lived proteins, and it was strongly inhibited by chloroquine and not by NaF. It is concluded from these results that the breakdown of endogenous proteins, both short-lived and long-lived, probably takes place partly (approximately 30%) in lysosomes and partly through one or more nonlysosomal mechanism(s) unaffected by chloroquine and presumably susceptible to inhibition by fluoride. A difference must exist between short-lived and long-lived proteins in the manner in which they reach lysosomes or are handled by these organelles; this difference would account for the selective effect of the supply of endocytosible materials on the lysosomal processing of long-lived proteins.

Fibroblasts in medium deficient in serum, amino acids, phosphate, or glucose stop synthesizing DNA and increase the rate of degradation of their long-lived cellular proteins approximately 2-fold. There is no difference in the rate of degradation of short-lived proteins under these conditions. Insulin, dexamethasone, and fibroblast growth factor act synergistically to inhibit protein degradation and to stimulate thymidine incorporation to about the same extent as serum. When the medium content in serum or fibroblast growth factor is varied over a wide range, there is a close, inverse correlation between the rate of protein degradation and the extent of thymidine incorporation. When serum is added to cells that have been deprived of serum, the inhibition of protein degradation is immediate whereas the enhanced rate of protein degradation in serum-free medium is attained within 1 hr after serum removal. A 30-min exposure to serum followed by incubation in serum-free medium was as effective as continuous exposure to serum in stimulating thymidine incorporation after 8-24 hr.

Over the last four years BT's Switched Multi-megabit Data Service has been a major success for the company. This has been due to a unique combination of features that make it genuinely easy for customers to dimension, manage and grow their wide area data networks cost effectively. This paper outlines how the underlying technology and service performance supports a set of features which translate into major business benefits and contribute to competitive advantage. The technology evolution path for SMDS in an ATM-based multi-service environment is described and service interworking scenarios discussed.

The article offers information on the first postage stamps in France.

The article presents information on the Bear Stamps released in Saint Louis, Missouri in 1845.

The article offers information on the use of the image of King Edward VII by Canadian postmaster Sir William Mulock for Canadian stamps.

A reprint of the article "The Stamps of Canada, Chapter 58 The 2 Cents Carmine of 1899," by B.W. H. Poole, which appeared in a Weekly Publication of the "Mekeel's & Stamps Magazine," is presented.

The article reports on the addition of 20 cents value to the stamps of Canada Chapter 59 on December 29, 1900 that was printed from the common style of line-engraved plate having the usual sheet arrangement of 100 stamps.

Part 25 of an article about stamps from Canada is presented and features the 1¢ and 3¢ stamps of 1868.

The article discusses the reproduction of the provisions of the law of the last session in Canada that are of philatelic interest including the promotion of the economy and simplicity of the business of the Post Office and the establishment of a Parcel Post and parcels of the Post Master General.

The article offers the author's insights on the history of Seeback stamps, wherein Hamilston Bank Note Co. of New York head Nicholas F. Seebeck made a deal with Republic of Salvador government to furnish postage stamps and postal stationery without cost within ten years.

The article presents the philatelic history of the grand-duchy of Mecklenburg-Schwerin, which lies south of the Baltic Sea.

This article offers information on the 1846 stamp issued by order of the postmaster of Alexandria, Virginia in 1846.

The article presents information on the history of the first postage stamps of the Philippines.

The article presents information on the first issue of postage stamps for the kingdom of Denmark.

The article provides information on the first postage stamps released in the Bahamas.

The article presents a reprint of the article "First Stamps of Buenos Aires," by B. W. H Poole, which appeared in the May 27, 1940 issue of "Mekeel's & Stamps."

A reprint of the article "Switzerland--1850 Federal Issue," published in the June 10, 1940 issue, which discussed the history of the postal system in Switzerland.

An excerpt from the August 15, 1938 issue of "Mekeel's Weekly" is presented.

The article discusses Canadian stamps including the formation provisional stamps, its usage, and bisections of the stamps in the post office of Port Hood, Canada.

The article discusses printing "2 Cents" on the 3¢ provisionals of Canada in order to defraud the government

An excerpt from an article published in the periodical Weekly Philatelic Era, on Imperial stamp of Canada in 1898 is presented.

The author comments on the Map Stamp design featured in the journal "Philatelic Record" for December 1898, explaining key features of the Imperial Penny Postage Stamp.

Several images of 1898 numeral issues of stamps of Canada are presented.

The article discusses the postal history of Chile.

This article explores the history of Carlist postage stamps of Spain.