Stock Balance Research Articles

Determination of DNA content in the nurse and follicle cells from wild type and mutant Drosophila melanogaster by DNA-Feulgen cytophotometry.

DNA replication patterns in the nurse and follicle cells of wild type and a female sterile mutant, fs(1)1304, of Drosophila melanogaster have been studied by DNA-Feulgen cytophotometry, using a cell dispersal technique that allowed the measurement of DNA amounts in individual nuclei from egg chambers of known developmental stages. DNA-Feulgen values associated with various ovarian nuclei from egg chambers at different stages of development were used to assess a base line DNA content for ovarian tissues and to estimate the extent of DNA replication in the nurse cells and follicle cells of growing and mature egg chambers. Our data show that both the nurse and follicle cells undergo multiple cycles of endonuclear DNA replication and that there may be selective amplification as well as underreplication by portions of the genome in these highly polyploid, ovarian cells. Alternative models are proposed to account for the DNA replication patterns observed. Comparisons of DNA-Feulgen levels in wild type ovarian nuclei with those found for the fs(1)1304 mutant and its heterozygote in the balanced stock fs/FM3, show that equivalent DNA levels are present in follicle cell nuclei from all three types of females. Nurse cell nuclei in the homozygous fs stock, however, fail to achieve the same high DNA levels observed in both fs/FM3 and wild type nurse cell nuclei. Although the nuclei of follicle cells in ovaries from fs/fs females appear morphologically like those surrounding egg chambers in wild type ovaries, nurse cell nuclei from mutant females show a more compacted organization of their chromatin than found for nurse cell nuclei from wild type ovaries at similar developmental stages. Our findings suggest that a major effect of the fs(1)1304 mutation may be on the coiling behavior of chromatin and the conformation of DNA-protein moieties in both nurse cell and follicle cell nuclei. These changes in chromatin structure apparently are manifest by perturbations in DNA replication patterns and normal gene function in these biosynthetically active cells.

Nuclear triiodothyronine receptors and metabolic response in perinatally protein-deprived rats.

Pregnant rats from day 14 of pregnancy and pups were fed a control diet (24% casein) or a deprived diet (8% casein) to obtain a control and a pre- and post-natal protein-deprived group. From 50 days of age, all groups were fed a balanced commercial stock diet for different periods. A significant reduction in body weight was observed in the perinatally protein-deprived group (PPD) after the different periods of nutritional recovery studied. Maximal binding capacity (MBC) and apparent affinity constant (Ka) of liver nuclear T3-receptors in the PPD group were similar to those in the control group. Mitochondrial alpha-glycerophosphate dehydrogenase (alpha-GPD) and cytosolic malic enzyme (ME) activity were significantly increased in the PPD group in all the periods of nutritional recovery studied, except in the 8 months old group where it was non-significant. Plasma T3 levels were higher in rats 3 and 15 days after the removal of the hypoprotein diet while it was normal after longer periods of nutritional recovery. Serum T4 was not modified in any group. The results indicate that protein undernutrition during perinatal life may induce an activation of hepatic T3-dependent enzymes which persists even after long periods of nutritional recovery. The lack of modification at the nuclear T3-receptor level, where supposedly the first T3-signal takes place, raises the possibility of an amplification of this signal at a step beyond the receptor.

A mutator factor in a strain of Drosophila melanogaster: identified by use of mutation, reversion rates and male recombination.

A set of 1,000 "mutation accumulation" lines Drosophila melanogaster, which originated from two different wild-type, lethal-bearing second chromosomes (Yamaguchi and Mukai 1974; Mukai and Cockerham 1977), was examined for evidence of a mutator factor by using the occurrence of recessive visible mutations and male recombination to identify its presence. The 1,000 lines were screened at approximately generation 240 for the presence of recessive visible mutation at twelve loci, by outcrossing to a balanced multiply marked second chromosome stock (Muller's "12ple" Bowling Green). Twenty-three lines were found to carry a visible mutation at one of the vg locus. mutations found in three lines, two at the dp locus and one at the vg locus, demonstrated instability as revertants to the wild type and were recovered and verified in these three cases. The three revertant lines, and three lines showing no reversion, were tested for their ability to induce male recombination. Male recombination was observed in the three lines in which revertants were recovered. Male and female sterility assays indicated conclusively that these "hybrid dysgenic" characteristics could not be used to identify lines potentially carrying mutator factors, whereas the consistent ability of the lines to induce high rates of reversion and male recombination was successful in determining that the "mutation accumulation lines" do possess mutator factors.

Beat frequency is bimodally distributed in spermatozoa from T/t12 mice.

Flagellar beat frequencies of spermatozoa from mice of varying genotype were studied using highspeed cinemicrography. Beat frequency was variable but unimodal in two inbred lines, their F1, and an outbred line. In contrast, beat frequency in spermatozoa from T-complex, balanced lethal stocks (T/t6 and T/t12) tended not to vary between individual males of each genotype up to four hours after collection. The two-hour distribution of beat frequency for T/t12 was, moreover, bimodal, suggesting the possible existence of two subpopulations of spermatozoa.

Persistent Changes in Central Catecholaminergic System After Recovery of Perinatally Undernourished Rats

Pregnant rats from day 14 of pregnancy or pups were fed a control diet (24% casein) or a deprived diet (8% casein) in order to obtain the following groups: 1) Control (C-C group); 2) Prenatal deprived (D-C group); 3) Postnatal deprived (C-D group); 4) Pre and postnatal deprived (D-D group). From 50 days of age on, all groups were fed a balanced commercial stock diet until 140 days of age. A significant reduction in corporal and brain weights was observed in C-D and D-D groups during deprivation and after nutritional recovery. Twenty-four day old deprived rats showed a decrease in brain noradrenaline (NA) content but no significant change in NA concentration. By the end of the deprivation period (50 days), brain NA levels tended to be reduced or increased in postnatal deprived rats, depending upon the method of expressing the results (microgram NA/whole brain or microgram NA/g fresh tissue, respectively). At 140 days of age, i.e., after 90 days of nutritional recovery, no differences were detected between deprived and control rats. However, conversion rate of [14C]tyrosine to brain catecholamines and tyrosine-hydoxylase activity were higher in D-D rats as compared with controls at this age. These results suggest that perinatal undernutrition produces, even after a prolonged period of nutritional recovery, a permanent activation of the central catecholaminergic system in adulthood. This fact may explain the different behavioral alterations described as a consequence of protein deprivation in early life.

Optimal Inventories via Customer Service Objectives

In this monograph, our aim is to show a basic approach to producing balanced stock ranges, thus avoiding the cost penalties of over stocking on the one hand whilst averting serious lost sales due to stock shortages on the other. Stocks should not be dealt with in a blanket fashion; certain selling items are a lot more important than others. Simple means of stock classification go a long way to revealing not only under and overstock situations but high priority stock ranges, growth areas, and most importantly declining products which may need phasing out altogether.

Ultrastructural studies of oocytes and embryos derived from female flies carrying the grandchildless mutation in Drosophila subobscura

The maternal effect mutant grandchildless in Drosophila subobscura has been analyzed with the electron microscope. The original mutation was linked to a visible genetic marker and established in a balanced stock. Oocytes and early embryos were examined by both transmission and scanning electron microscopy. The earliest defect is seen in mutant eggs and occurs at the end of oogenesis. In the cortex, at both the anterior and the posterior tips, regions appear which are free of ribosomes, mitochondria, and other cytoplasmic organelles. Most of the polar granules are included in these regions at the posterior tip. Following oviposition, this cytoplasmic segregation is no longer observed and most polar granules have disappeared. The few remaining granules are presumed to derive from the peripheral polar plasm which does not become segregated. During embryogenesis there is a retarded movement of nuclei to the anterior and posterior cortices. At the posterior tip nuclei are delayed in reaching the lateral sides and never move directly into the posterior polar plasm. Pole cells never form. After the last syncytial division the lateral nuclei move under the posterior polar plasm to complete the blastoderm. The posterior polar plasm itself protrudes during blastoderm formation as long cytoplasmic extensions which separate from the blastoderm as cytoplasmic blebs. Neither polar granules nor mitochondria are found in these blebs. The grandchildless phenotype is due to the failure of nuclei to migrate directly into the posterior polar plasm. The defect in the polar plasm presumably is related to the process in mature eggs whereby portions of the cortex become segregated at both anterior and posterior tips. This process may change the properties of the posterior polar plasm so that nuclei do not penetrate into it.

Inflation, Taxes, and the Public Debt

THE TRADITIONAL ANALYSIS of a perfectly anticipated inflation develops the following scenario: the government announces and the public believes that, at a given date, the rate of inflation will be x percent per annum. If, for example, x is higher than the previously anticipated rate, the rise in the opportunity cost of holding real balances will induce individuals to reduce the stock of real balances until its productivity on the margin is raised sufficiently to balance the higher opportunity cost. That this reduction in the stock of real balances implies that over some time interval the rate of price change must differ from its equilibrium rate is acknowledged (if the blip in the price level occurs at an instant of time, at that instant the rate of inflation is infinite). This makes the assumption of a fully anticipated inflation shaky, but the problem of the transition is swept under the rug and the analysis focuses on the steady-state equilibrium price path. Moreover, the change in real balances may alter outside wealth and disposable income, thereby changing the ratio of investment to income, and with it the real rate of interest. Having acknowledged this, the analysis often proceeds under the assumption that the real rate is constant.

Short-Run and Long-Run Effects of External Disturbances under a Floating Exchange Rate

number of ways. Both in the short run and in the long run the model respects the flow of funds and balance sheet identities or stock-flow constraints that characterize all properly specified sequential temporary (or momentary) general equilibrium,1 open-economy models with money and other financial claims. The so-called approach to the balance of payments represents the simple end of the wide spectrum occupied by this class of models.2 The determination of the level of real economic activity and of the current account balance is consistent with the absorption approach.3 The role of import and export price elasticities in the determination of the trade balance is clearly brought out.4 In spirit the model has a close affinity to the ideas developed by Turnovsky (1977). The economy is small (i.e., a price-taker) in the international financial market and in the markets for its imports, but can affect the world price for its exports. The short-run behaviour of the economy is Keynesian. The money wage and the price of domestic output are sticky. Domestic output is determined by effective demand. As time passes, both the money wage and the price of domestic output respond to excess demand pressures. The long-run, steady-state properties of the model are those of a strictly classical growth model. The model is specified in such a way as to bring out very clearly the importance for the adjustment process of relative price changes. Both exogenous and endogenous changes in relative prices are considered. Changes in the terms of trade will affect the economy by altering real income and real wealth as well as via substitution effects. In monetary models of the balance of payments, exchange rate changes affect private spending and portfolio allocation decisions via the wealth effects of the changes in the general price level that they bring about. Depreciation increases the domestic currency price of traded goods. This reduces the real value of the nominal stock of money balances (and of any other nominally denominated private assets). This inflationary effect of

Correct Fixed-capital Replacement in Input-output Growth Models

Under constant technique defined by constant current 3 and capital-capacity and inventory-output coefficients and constant lengths of fixed-capital lives, then, under steady growth, fixed capital comprises a set of balanced stocks which undergo apparent radioactive decays defined by the lengths of lives and the growth rate. The principle behind this fact was elucidated some time ago by R. Eisner [3], and almost as explicitly by J. von Neumann ([14] p. 2, note (e)), but it has been unfortunately ignored in subsequent literature. This article endeavours to put matters straight with particular reference to steady-state and non-steady-state n-industry models employing square input-output matrices, n> 0. The matter at issue is this: providing an economy's history is entirely known, this year's 4 replacements of fixed capital may be listed by industry of origin, as a vector d, or by industry of origin and use, as a matrix D; also, since last year's capacity outputs of industries and extensions thereto are known, so are this year's capacity outputs, and the respective columns of D may be divided by them giving a matrix of ratios U of fixed-capital replacements by industry of origin divided by capacity output of industry of use. Moreover, if the economy has long grown, with capacity operation of its industries, at a common growth rate r, with unchanging technique, and continues to grow so, both the vector d and the matrix D will do likewise from this year to next year and so on; the matrix of ratios U will then be invariant. However, in general, previous growth may not have been steady growth, and in this case (as well as for steady growth) both d, D and U are always a function of everything that has happened previously up to and including last year . Except for the case of prior and continuing (exponential) growth at the common rate r, one cannot dictate steady future growth of the elements of fixedcapital replacements in d and D, nor can one state accurately, using D (before solving for industries' outputs), the proper ratios of fixed-capital replacements to this year's industries' outputs. (The latter are not necessarily the capacity outputs obtained from last year's information; see Concluding Remarks below. If solved-for outputs q do equal capacity outputs q*, U is a correct matrix; otherwise it is arbitrary and both q, and d and D (obtained from U and q) are incorrect). Stone and Brown, in [13], want to solve the problem of the conditions for sustained growth; commodities given in final consumption are to grow at their own specific rates, or at a common rate, for this [outputs' solution] year and all future years. For reasons just given, they are wrong in dictatorially including the vector of fixed-capital replacements d in their final-consumption vector e, the first possibility that they mention, and they may also be wrong in trying to make a modification of [their] matrix [of current 5

Demand and Supply Functions for Stocks of Euro-Dollar Deposits: An Empirical Study

T HIS study considers the market for Eurodollar deposits as a structural system with determinate demand and supply relationships. It is important at the outset to distinguish the stock demand for Euro-dollar deposits, which we shall be investigating here, from the flow demand for Euro-dollar credit. Machlup (1970) points out that the demand for Euro-dollar credit is a demand for a flow of funds to borrowers who, in turn, plan to pay out the funds they have borrowed. The demand for Euro-dollar deposit balances is, on the other hand, a demand for money, or near-money, to hold. We shall be concentrating upon the factors affecting the demand for a stock of Eurodollar deposits to hold.1 Since we shall not be taking the stock of Euro-dollar deposits in existence at a point in time as exogenously given, we shall also be identifying an equation to determine the stock of Euro-dollar balances supplied by Euro-dollar issuing institutions (hereafter Euro-banks). This will be based on an identifiable stock of reserves held by Euro-banks. Briefly, the procedure and results are as follows. Quarterly data from 1964-III through 1970-IV are employed to obtain parameter estimates for scale and substitution arguments in a stock demand function for Euro-dollar deposit balances as well as to obtain an estimated equation for the stock of dollar claims produced by Euro-banks. The empirical results suggest that a stable stock-demand function for Euro-dollar deposit balances exists along with a stable stock-supply function for Eurodollar deposits. The results also suggest that about 40 per cent of the growth of Euro-dollar deposits in the 1964-III 1970-IV period was due to the multiple deposit expansion process.

A cytogenetic study of radiation damage in entire genomes of drosophila

Adult Drosophila melanogaster males, aged 1–2 days, were X-irradiated with 4000 R and mated for approximately 48 h to females containing genetic markers and/or crossover suppressors in all chromosomes. F1 females of the desired genotype were collected and appropriate genetic schemes followed to arrive at balanced stocks of entire treated genomes. Each chromosome of each genome was observed for visibles, lethals, sterility factors and extreme detrimentals. All chromosomes of each genome were examined cytologically for deficiencies, inversions, transpositions, etc., and to determine the breakpoints of translocations, previously detected genetically. Of the 310 genomes analyzed, 63.2% were found to contain genetic damage. It can be calculated that approximately 2265 genomes were actually irradiated, of which 10.7% transmtted genetic damage to succeeding generations. Inherited damage was tabulated in terms of damaged “sites”, a site being either a point mutation or a chromosome break. The number of sites in any particular genome varied from 1. to 6, there were on the average 1.12 sites per genome, and the average number of sites per chromosome was found to be related to mitotic length. Analyses were made of the interrelationships of the different types of damage by tabulating rearrangements according to cytological nature, viability, fertility and phenotypic expression, of recessive lethals according to cytological nature, and of visibles according to cytological nature, viability and fertility.

The Real Balance Effect: An Exercise in Capital Theory

In his celebrated book, Money, Interest and Prices, Professor Patinkin took the position that an individual's demand for nominal balances was not homogeneous of the first degree in the absolute level of prices. His analysis, based on concepts of inferiority and superiority with respect to real cash balances, failed to distinguish between short-period transition and long-period equilibrium. For this failure, Patinkin was taken to task by Archibald and Lipsey, who, while accepting Patinkin's assumptions, showed that as between alternative positions of long-period equilibrium when the actual stock of real balances is equal to the desired stock, a doubling of the price level does, in fact, double the nominal quantity of cash balances demanded, thereby validating the classical position.My primary purpose is to show that it is unnecessary to assume, as do Patinkin and his critics, a unique relation between the desired stock of balances and the flow of commodities. This stock-flow equilibrium should not be assumed, but rather can be deduced, as is done in capital theory, from initial assumptions. Indeed, the accumulation of cash balances to attain a long-run equilibrium level is properly treated as an aspect of the theory of capital accumulation. Specifically, if we assume that real cash balances have positive carrying costs and that the rate of time preference is zero, we can show that an individual in long-run equilibrium will hold the satiety level of cash balances and that the equilibrium is unique and stable.

A BALANCED STOCK WITH TRIPLE EYE-COLOR ALLELES IN THE WASP MORMONIELLA

Journal Article A BALANCED STOCK WITH TRIPLE EYE-COLOR ALLELES IN THE WASP MORMONIELLA Get access P. W. WHITING P. W. WHITING University of PennsylvaniaPhiladelphia Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Heredity, Volume 46, Issue 6, November 1955, Page 270, https://doi.org/10.1093/oxfordjournals.jhered.a106576 Published: 01 November 1955

Effect of Soils on the Establishment of Tree Crops

The importance of soil factors to the establishment of tree crops is well recognized by forest soil scientists and foresters. It has, however, been overlooked by far too many foresters responsible for major forestation projects. The soil factors found to be significant in the establishment of both planted stock and seedlings from natural or artificial seedfall are: texture and structure characteristics of the soil profile as they affect moisture and aeration; depth to the ground water table; content of soil organic matter; chemical properties, including soil fertility and the occurrence of layers high in soluble salts and toxic substances. The importance of producing nutritionally balanced or physiologically balanced planting stock has been recognized, and more attention is being paid to nursery soil management practices in an effort to improve the survival qualities of seedlings. The importance of mycorrhizal fungi as related to seedling survival has also been well established. These relationships are well recognized in the east where foresters have been at grips with the problems for some time. In the west, foresters are just beginning to see the significance of soil factors; the specific soil-site relationships affecting the survival and growth of a tree crop need to be established for western conditions.

BRONCHIAL CHANGES IN EXPERIMENTALLY INDUCED CYSTIC DEGENERATION OF THE PANCREAS

IN A RECENT report on the induction of cyst formation and consequent fibrosis in the pancreas¹it was said that in the lungs various changes, such as hemorrhages and emphysema, occurred but squamous metaplasia or other bronchial changes were absent. Since the presentation of that study, several new series of similar experiments have been carried out and their results, together with those seen on reexamination of the original preparations, revealed data that made us revise this previous statement, especially since bronchial changes were also observed in animals in which the pancreatic lesion was provoked by deficient diets. <h3>MATERIAL AND METHODS</h3> Seventy-one male albino rats, ranging in weight from 160 to 190 Gm. were used. Thirty-five animals were fed a well balanced stock diet with a liberal supplement of water-soluble vitamins and cod liver oil with added vitamin A. The amount of neither food nor water was restricted. Carbon tetrachloride,

Cystic change in the pancreas; its experimental production.

IN 1945, an unusual change was observed in the pancreas of an infant who had died from dysentery associated with nutritional edema resulting from a diet lacking animal protein. The change consisted in cystic atrophy of a small part of the acinar tissue. Other parts of the excretory system and the islets seemed to have remained intact. Reproduction of the change experimentally was attempted by the use of various deficient diets and toxic agents. Trials to induce the lesion by dietary means were successful. 1 However, chronic poisoning by small doses of carbon tetrachloride brought about regular production of this change in our series. EXPERIMENTAL METHOD Male albino rats of the same strain, ranging in weight from 160 to 190 Gm., were used. They were fed a well balanced stock diet, with a liberal supplement of water-soluble vitamins and cod liver oil with added vitamin A. The daily amount of

Effect of Light and of Darkness on Thyroid Gland

That darkness or the absence of ultraviolet radiation, particularly of the antirachitic portion, leads to an hyperplasia of the thyroid gland has been suggested by some investigators and denied by others. A critical analysis of these results, however, reveals many discrepancies and contradictions. The present study extended from November, 1932, through July, 1933, arid involved the use of 140 albino rats. Of this number, 40 were offspring of stock animals bred and kept in the rat room illuminated by diffuse daylight filtered through window glass. The remainder were offspring of rats kept and bred in a dark room, the only radiation coming from a ruby lamp used for a brief period daily while feeding, cleaning, or weighing. The animals were grouped at weaning (21–28 days), weighed weekly, and kept under the various experimental conditions until they were from 12 to 16 weeks old. At the end of each 4-week period, representative animals from each group were sacrificed and the thyroids removed for histological examination. The experiments were divided into 2 series: (1) in which the rats were fed a balanced stock ration, Bal-Ra, rich in iodine; (2) in which the rats were fed bread and fresh milk, a diet relatively poor in iodine. In the first series, one-half of the animals born in light were allowed to remain in the “light room” and groups exposed for 15 minutes every other day at a distance of 1 meter from a flaming carbon arc, burning “Sunshine” carbons (total energy value of each exposure = 6.51 gm. cal. per sq. cm.; ultraviolet = 0.273 gm. cal. per sq. cm.) and to sunlight from 10 A. M. to 2 P. M. daily. The remaining 20 rats were placed in the dark room and kept there except when they were being irradiated.

Comparative Studies of Histological Skin Changes Produced by X-Rays and by Lipoid Solvents

By varying the time period of exposure and transmitting the ray through an opening 1 cm. in diameter, we have produced various degrees of x-ray burns of the skin in a series of white rats. The quantity of x-rays used varied from 5 miliampere minutes to 50 miliampere minutes. Animals were placed on high vitamin A, low vitamin A, and balanced stock rations to determine if these dietaries would produce a difference in reaction to the x-rays. Our studies, thus far, have not shown any striking differences. The characteristic gross picture is depilation over the area of skin exposed, with the persistence of a roughened, scarred skin that appears from 14 to 21 days after the exposure to the x-rays. Five miliampere minutes and 10 miliampere minutes produce no effect grossly apparent. Microscopically the lesion is that of shrinking and edema of the epithelial layer, hyperplasia of the hair follicles, and in some cases a metaplasia of the basal layer of the skin. The subcutis shows varying degrees of hyalinization. With the high doses (50 miliampere minutes) there is a hyalinization of the subcutis and the glandular structures in it. The epithelium remains intact over the area, the higher dosages producing a pyknosis of the cell nuclei and a hyalinization of the cytoplasm. In the second series we applied a 50 per cent coal tar or pine tar preparation to a denuded area 2 cm. in diameter. The white rat was used. The tar was painted on the area with a cotton swab every 2 or 3 days. A roughening of the skin and a gradual loss of hair was noted grossly. Microscopically a hyperkeratosis begins at the 30th day, and gradually progresses.

Studies on Fatty Infiltration of the Liver Induced by Lipoid Solvents.

In a previous paper, Johnston and the author reported that fatty infiltration of the liver occurs a certain period of time after the injection of a mixture of mineral oil and coal tar into the subcutaneous tissue of rats fed a diet rich in vitamin A. We thought at that time that this mixture of lipoid solvents alone produced the fatty infiltration in these animals. More recent studies have shown that this is not true. It was a time factor only which brought about the action of the mixture of mineral oil and coal tar. Later experiments have shown that other lipoid solvents will produce the same effect in the liver after a longer interval of time. A mixture of coal tar and paraffin produces the change 30 days after the injection, coal tar in 90 days, mazola oil in 60 to 90 days, mineral oil in 45 to 60 days, and a mixture of coal tar and mazola oil in 40 to 60 days. Thus, the time of occurrence of the fatty infiltration is governed by the particular kind of lipoid solvent used. At the times given above there is an extensive infiltration involving the entire parenchyma of the liver. Previous to this time in certain of the above series a few scattered areas of vacuolization were found in a few of the livers. The infiltration does not occur in the animals fed a ration deficient in vitamin A, and only to a slight degree in the animals fed a well balanced stock ration. It does not occur in rats fed a rich vitamin A dietary that are not injected with the substances listed above. These substances are lipoid solvents.