scholarly journals A Long Term Experiment with Rats on a Human Dietary

1935 ◽  
Vol 35 (4) ◽  
pp. 476-497 ◽  
Author(s):  
John Boyd Orr ◽  
William Thomson ◽  
R. C. Garry

For 2¼ years a large colony of rats was maintained on a diet based on a dietary survey of a human population. One-half of the rats was fed on the human survey diet, or this diet with a small increase in milk, the other half on the same diet supplemented with additional milk and green food. Four generations of animals were reared, all from the same stock.The rats on the human diet with additional milk and green food were healthy in all respects so far as can be judged from our own rats on a stock diet and from the data of other workers.On the other hand, in spite of an exactly similar environment and heredity, the animals without additional milk and green food, showed:(1) a slightly impaired reproductive capacity;(2) a very markedly increased death-rate due to increased susceptibility to an infection to which all rats were equally exposed;(3) a definitely slower rate of growth;(4) a lower haemoglobin content in the blood; and,(5) a clinically poorer condition as judged by behaviour and state of the coat.These findings are discussed and the possibility of applying them to human dietetic problems briefly touched upon.

1985 ◽  
Vol 104 (1) ◽  
pp. 125-133 ◽  
Author(s):  
K. Chaney ◽  
D. R. Hodgson ◽  
M. A. Braim

SummaryPhysical measurements were made on the soil of a long-term cultivation experiment comparing direct drilling, tine cultivation and mouldboard ploughing for spring barley to investigate possible reasons for differences in yield. The soil was a typical argillio brown earth, approximately 90 cm of sandy clay loam topsoil and clay loam subsoil overlying magnesian limestone. For the three periods 1971–4, 1975–7 and 1978–80 the mean grain yields were marginally lower after direct drilling than after shallow cultivation or ploughing. There was an average decline in yield of 1·33 t/ha from the first to the last period, the decline being greater for direct drilling than the other two tillage systems. Although the surface horizon (0–5 cm) of direct-drilled soil had a higher content of organic matter than the ploughed, this did not increase the stability of the aggregates. Slaking tests had shown the soil to be inherently unstable and likely to suffer from structural problems. After the first 3 years bulk density of direct-drilled soil (0–15 cm) increased markedly to ca. l·5 g/cm8 and then remained relatively stable. In the ploughed soil, density increased steadily over the period to an average value of co. 1·45 g/cm8. Tine cultivation to 7–8 cm reduced cone resistance values in the surface compared with direct-drilled soil but below 15 cm there were no significant differences. Ploughing gave significantly lower values than direct drilling to a depth of 30 cm. Measurements of pore sizes in direct-drilled and ploughed soil were highly variable with few significant differences. Mean air capacity values (1978–80) tended to be lower in direct-drilled than in ploughed topsoil particularly for plots direct drilled after 7 years of deep tine cultivation. A limited number of root measurements in 1978 and 1980 showed that the length of root per unit of ground area was much less after direct drilling than after ploughing. Shallow cultivation, surprisingly, gave most root with a greater proportion of the root system below 20 cm than in the other two treatments. The classification of this soil according to its suitability for direct drilling cereals is discussed.


1939 ◽  
Vol 39 (2) ◽  
pp. 91-108 ◽  
Author(s):  
W. E. Gaunt ◽  
J. T. Irving ◽  
W. Thomson

1. A group of rats has been fed on a poor human dietary supplemented with milk and green food. A further group has been given the same dietary supplemented with Ca and P as salts, equivalent in amount to that present in the milk and green food. The experiment has been continued over three generations.2. The diet supplemented with Ca and P salts has been found to be as effective as that containing milk and green food in promoting reproduction, calcification and tooth formation; it has induced growth as effectively in the first generation of rats but is unable to maintain this growth rate as effectively over several generations. It is obvious that Ca and P are of the chief deficiencies in the poor diet. The addition of these elements greatly increases the nutritive value of this diet, but they are inferior in this respect to milk and green food supplements.3. Under conditions of Ca and P lack, tooth formation is much less adversely affected than is skeletal ossification.


2021 ◽  
Author(s):  
Minako Izutsu ◽  
Devin M. Lake ◽  
Zachary W. D. Matson ◽  
Jack P. Dodson ◽  
Richard E. Lenski

Population bottlenecks are common in nature, and they can impact the rate of adaptation in evolving populations. On the one hand, each bottleneck reduces the genetic variation that fuels adaptation. On the other hand, fewer founders can undergo more generations and leave more descendants in a resource-limited environment, which allows surviving beneficial mutations to spread more quickly. Here we investigate the impact of repeated bottlenecks on the dynamics of adaptation in experimental populations of Escherichia coli. We propagated 48 populations under four dilution regimes (2-, 8-, 100-, and 1000-fold), all reaching the same final size each day, for 150 days. A simple model in which adaptation is limited by the supply rate of beneficial mutations predicts that fitness gains should be maximized with ~8-fold dilutions. The model also assumes that selection acts only on the overall growth rate and is otherwise identical across dilution regimes. However, we found that selection in the 2-fold regime was qualitatively different from the other treatments. Moreover, we observed earlier and greater fitness gains in the populations subjected to 100- and 1000-fold dilutions than in those that evolved in the 8 fold regime. We also ran simulations using parameters estimated independently from a long-term experiment using the same ancestral strain and environment. The simulations produced dynamics similar to our empirical results under these regimes, and they indicate that the simple model fails owing to the assumption that the supply of beneficial mutations limits adaptation.


2005 ◽  
Vol 44 (03) ◽  
pp. 107-117
Author(s):  
R. G. Meyer ◽  
W. Herr ◽  
A. Helisch ◽  
P. Bartenstein ◽  
I. Buchmann

SummaryThe prognosis of patients with acute myeloid leukaemia (AML) has improved considerably by introduction of aggressive consolidation chemotherapy and haematopoietic stem cell transplantation (SCT). Nevertheless, only 20-30% of patients with AML achieve long-term diseasefree survival after SCT. The most common cause of treatment failure is relapse. Additionally, mortality rates are significantly increased by therapy-related causes such as toxicity of chemotherapy and complications of SCT. Including radioimmunotherapies in the treatment of AML and myelodyplastic syndrome (MDS) allows for the achievement of a pronounced antileukaemic effect for the reduction of relapse rates on the one hand. On the other hand, no increase of acute toxicity and later complications should be induced. These effects are important for the primary reduction of tumour cells as well as for the myeloablative conditioning before SCT.This paper provides a systematic and critical review of the currently used radionuclides and immunoconjugates for the treatment of AML and MDS and summarizes the literature on primary tumour cell reductive radioimmunotherapies on the one hand and conditioning radioimmunotherapies before SCT on the other hand.


2018 ◽  
pp. 49-68 ◽  
Author(s):  
M. E. Mamonov

Our analysis documents that the existence of hidden “holes” in the capital of not yet failed banks - while creating intertemporal pressure on the actual level of capital - leads to changing of maturity of loans supplied rather than to contracting of their volume. Long-term loans decrease, whereas short-term loans rise - and, what is most remarkably, by approximately the same amounts. Standardly, the higher the maturity of loans the higher the credit risk and, thus, the more loan loss reserves (LLP) banks are forced to create, increasing the pressure on capital. Banks that already hide “holes” in the capital, but have not yet faced with license withdrawal, must possess strong incentives to shorten the maturity of supplied loans. On the one hand, it raises the turnovers of LLP and facilitates the flexibility of capital management; on the other hand, it allows increasing the speed of shifting of attracted deposits to loans to related parties in domestic or foreign jurisdictions. This enlarges the potential size of ex post revealed “hole” in the capital and, therefore, allows us to assume that not every loan might be viewed as a good for the economy: excessive short-term and insufficient long-term loans can produce the source for future losses.


1960 ◽  
Vol XXXIII (IV) ◽  
pp. 630-636
Author(s):  
F.-E. Krusius ◽  
P. Peltola

ABSTRACT The study reported here was performed in order to examine the tap water of Helsinki for its alleged goitrogenous effect. In a short-term, 24-hour experiment with rats, kept on an iodine-poor diet, we noticed no inhibition of the 4-hour 131I uptake, as compared with that of animals receiving physiological saline instead of tap water. Two similar groups of rats receiving 1 and 2 mg of mercazole in redistilled water showed a distinct blockage of the 4-hour uptake, which proved the effect of this substance. In a long-term experiment of 5 weeks' duration there was no detectable difference in the body weight, thyroid weight and the 4-hour 131I uptake when the rats receiving tap water or distilled water to which 0.45 per cent of sodium chloride was added were compared with each other. Replacement of tap water by a 10 mg per cent solution of mercazole in redistilled water enlarged the thyroid to double its normal weight and increased the 131I uptake to approximately five times that of the controls. Thus our experiments failed to demonstrate any goitrogenous effect in the tap water of Helsinki. Changes similar to those produced by a long-term administration of mercazole, i. e. an enlargement of the thyroid and an increased thyroidal iodine uptake, have been shown to be due to milk collected from goitrous areas. The observations here reported confirm the importance of milk in the genesis of the goitre endemia of Helsinki. Attention is further called to the fact that a thyroidal enlargement combined with an increased thyroidal iodine uptake cannot always be taken as a sign of iodine deficiency because similar changes may be produced by the administration of goitrogens.


2010 ◽  
Vol 59 (2) ◽  
pp. 295-314 ◽  
Author(s):  
Imre Kádár

Egy műtrágyázási tartamkísérlet 32. évében, 2005-ben vizsgáltuk az eltérő N-, P- és K-ellátottsági szintek és kombinációik hatását a réti csenkesz (Festuca pratensis) vezérnövényű, nyolckomponensű, pillangós nélküli gyepkeverék termésére, fejlődésére és elemtartalmára. A termőhely mészlepedékes csernozjom talaja a szántott rétegben mintegy 3% humuszt, 3–5% CaCO3-ot és 20–22% agyagot tartalmazott, N és K elemekben közepesen, P és Zn elemekben gyengén ellátottnak minősült. A kísérlet 4N×4P×4K = 64 kezelést×2 ismétlést = 128 parcellát foglalt magában. A talajvíz 13–15 m mélyen helyezkedik el, a terület aszályérzékeny. A vizsgált 2005. évben azonban kielégítő mennyiségű (649 mm) csapadék hullott és annak eloszlása is kedvező volt. A gyep telepítése spenót elővetemény után 2000. szeptember 20-án történt gabona sortávra 60 kg·ha–1 vetőmaggal, amelynek 25%-át (15 kg) a réti csenkesz (Festuca pratensis); 21–21%-át (12,6 kg) a nádképű csenkesz (Festuca arundinacea) és az angol perje (Lolium perenne); 9%-át (5,4 kg) a taréjos búzafű (Agropyron cristatum), valamint 6–6%-át (3,6 kg) a vörös csenkesz (Festuca rubra), a réti komócsin (Phleum pratense), a zöld pántlikafű (Phalaris arundinacea) és a csomós ebír (Dactylis glomerata) tette ki. Főbb eredményeink: – A meghatározó N-trágyázás nyomán a szénatermés 5-szörösére emelkedett a két kaszálással a N-kontrollhoz viszonyítva. A maximális 10 t·ha–1 körüli légszáraz szénahozamokat a 300 kg N·ha–1·év–1 N-adag, valamint a 150 mg·kg–1 körüli AL-P2O5-, illetve 150 mg·kg–1 feletti AL-K2O-tartalom biztosította. Növénydiagnosztikai szempontból a nagy terméshez kötődő optimális elemtartalom 2% körüli N- és K-, illetve 0,2–0,3% P-koncentráció volt a szénában. – A két kaszálással felvett minimum (a 2 t·ha–1 körüli szénatermést adó N-kontroll) és maximum (a 10 t·ha–1 körüli szénahozamú, nitrogénnel és PK-vel jól ellátott talajok) elemmennyiségek a következőképpen alakultak: N 21–196 kg, K 39–188 kg, Ca 9–48 kg, Mg 4–22 kg, P 6–21 kg. – Az N×P és N×K kölcsönhatások kifejezettebbé váltak a 2. kaszálás idején. A P 0,18–0,55%, a NO3-N 86–1582 mg·kg–1, a Cu 4,7–7,4 mg·kg–1, a Mo 0,7–4,1 mg·kg–1 extrém értékeket jelzett az N×P kezelések függvényében. Az N×K kezelésekben a K 1,44–2,73%, a Mg 0,26–0,39%, a Na 71–2178 mg·kg–1, a Ba 4,1–9,6 mg·kg–1, a Cd 15–44 µg·kg–1 szélsőértékekkel volt jellemezhető. A Sr a 10–26 mg·kg–1 koncentrációtartományban módosult a P×K-ellátottság nyomán. Élettani, takarmányozástani szempontból az indukált kölcsönhatások nyomon követése elengedhetetlen, amennyiben olyan mérvű tápelemhiányok, illetve aránytalanságok jöhetnek létre, melyek anyagcserezavarokat okozhatnak a növényt fogyasztó állatban.


2013 ◽  
Vol 62 (2) ◽  
pp. 311-330
Author(s):  
Jakab Loch ◽  
János Lazányi

Az Országos Műtrágyázási Tartamkísérletek (OMTK) tizenkét NPK kezeléskombinációjában, kilenc termőhelyen vizsgáltuk az NPK-trágyázás hatását az őszi búza és a kukorica termésére és a talajok 0,01 M CaCl2-oldható tápelemtartalmára. A termőhelyek: Bicsérd (BI), Hajdúböszörmény (HA), Iregszemcse (IR), Karcag (KA), Keszthely (KE), Kompolt (KO), Mosonmagyaróvár (MO), Nagyhörcsök (NA), Putnok (PU). Az NPK kezelések: 000, 101, 111, 121, 201, 220, 221, 222, 331, 341, 421, 441. A N- és P-kezelések a kódoknak megfelelően 50 kg N, ill. P2O5·ha−1, a K-adagok 100 kg K2O·ha−1 hatóanyag-mennyiséggel növekszenek. Az őszi búza termésadatok a 23., 24., 27., 28. és 31. évi kísérletekből, a kukoricatermések a 25., 26., 29. és 30. évből származnak.Az NPK-kezelések jelentősen növelték az őszi búza és a kukorica öt-, illetve négyéves átlagtermését, szignifikáns különbségek jöttek létre a termőhelyek átlagában. Az NPK-kezelések különböző érvényesülése az egyes termőhelyeken az eltérő ökológiai viszonyok, köztük a különböző eredeti tápelemtartalom és szolgáltató képesség következménye.Az NPK-kezelések hatására a talajok 0,01 M CaCl2-oldható tápelemtartalma is jelentősen változott. A növények tápelemigényét meghaladó kezelések tartamhatásaként tápelem-felhalmozódás igazolható mindhárom tápelem esetében. A növények szükségletét meghaladó N-adagok, a karbonátos talajokat és a nagy agyagtartalmú kompolti (KO) talajt kivéve csökkentették a talaj pH-t. A másodfokú görbék az őszi búza ötéves termésátlaga és a 0,01 M CaCl2-ban mért összes-N, P- és K-tartalom közötti összefüggéseket szemléltetik termőhelyenként.A legnagyobb kezeléshatások azokon a talajokon igazolhatók, melyeken a kontroll 0,01 M CaCl2-oldható összes-N értéke kisebb, mint 5–10 mg·kg−1. A 15,0 mg·kg−1 érték felett altalaban nem érvényesült a nitrogén termésnövelő hatása. Kivételt képez a tápanyagban gazdag, hajdúböszörményi nem karbonátos réti talaj. A foszfor termésnövelő hatása 2,0 mg P·kg−1 érték felett — a karbonátos réti talaj kivételével — általában nem érvényesül. Az összefüggéseket jellemző R2 meghatározottsági tényezők a legkisebbek az őszi búza és a talaj 0,01 M CaCl2-oldható K-tartalma között, ami az egyéb tényezők nagyobb szerepére utal.A bemutatott eredmények igazolják, hogy a 0,01 M CaCl2-oldható N-, P- és Kfrakciók alkalmasak a tápanyaghiány és -felesleg jellemzésére. Egyben igazolják, hogy az eltérő ökológiai viszonyok között nagyobb terméskülönbségek jöhetnek létre, mint a kezelések hatására. A környezetkímélő tápanyag-gazdálkodás megköveteli a tápanyagok eltérő érvényesülésének figyelembevételét.A termésadatok átengedéséért köszönet az OMTK Hálózati Tanács elnökének, titkárának, és valamennyi kísérletfelelősnek.


2018 ◽  
Vol 59 (1) ◽  
pp. 65-79
Author(s):  
Katarzyna Nikorowicz-Zatorska

Abstract The present paper focuses on spatial management regulations in order to carry out investment in the field of airport facilities. The construction, upgrades, and maintenance of airports falls within the area of responsibility of local authorities. This task poses a great challenge in terms of organisation and finances. On the one hand, an active airport is a municipal landmark and drives local economic, social and cultural development, and on the other, the scale of investment often exceeds the capabilities of local authorities. The immediate environment of the airport determines its final use and prosperity. The objective of the paper is to review legislation that affects airports and the surrounding communities. The process of urban planning in Lodz and surrounding areas will be presented as a background to the problem of land use management in the vicinity of the airport. This paper seeks to address the following questions: if and how airports have affected urban planning in Lodz, does the land use around the airport prevent the development of Lodz Airport, and how has the situation changed over the time? It can be assumed that as a result of lack of experience, land resources and size of investments on one hand and legislative dissonance and peculiar practices on the other, aviation infrastructure in Lodz is designed to meet temporary needs and is characterised by achieving short-term goals. Cyclical problems are solved in an intermittent manner and involve all the municipal resources, so there’s little left to secure long-term investments.


2018 ◽  
Vol 9 (2) ◽  
pp. 33-48
Author(s):  
Rivaldy Februansyah ◽  
Ika Yanuarti

The manufacturing sector is one of the most dominant economic sectors in in achieving growth and development in Indonesia. It needs adequate fund to develop its business. The sources of fund are from internal and external. The firm usually optimized the usage of internal fund prior to external fund. The internal fund comes from equity while the external funds are from debt and stock. Debt is also known as financial leverage. There is a phenomenon that the usage of debt increased the firm’s financial performance, since interest on debt could lower the payment of tax (tax shield). On the other side, the higher the financial leverage the higher the risk of bankruptcy. This research aims to analyze whether financial leverage has an influence on financial performance in the manufacturing sector listed on the Indonesia Stock Exchange (IDX) period 2015. The method of analysis used in this research is multiple linear regression analysis. This research uses quantitative approach with a sample of 140 listed companies in the manufacturing industry. The firm’s financial performance could be measured by the financial ratios. Financial Leverage ratios are ratios that measure the ability of firm’s to meet its financial obligation and the level of usage debt as compared to equity. There are several financial leverage ratios that used in this research, such as Debt Ratio (DR), Debt to Equity Ratio (DER), Interest Coverage Ratio (ICR), and Long Term Debt Ratio (LTDR). Financial performance indicates the ability of firm to generate profit and measured by Profitability Ratio. Return on Asset (ROA) is one of the Profitability Ratio. The statistical result shows that Debt Ratio (DR) negatively affect Return on Asset (ROA) and Interest Coverage Ratio (ICR) positively affect Return on Asset (ROA). Meanwhile, Debt to Equity Ratio (DER) and Long Term Debt Ratio (LTDR) did not affect Return on Asset (ROA). On the other hand, result shows that Debt Ratio (DR), Debt to Equity Ratio (DER), Interest Coverage Ratio (ICR), and Long Term Debt Ratio (LTDR) affect Return on Asset (ROA) simultaneously. Keywords: Financial Leverage, Debt Ratio (DR), Debt to Equity Ratio (DER), Interest Coverage Ratio (ICR), Long Term Debt Ratio (LTDR), Financial Performance, Return on Assets (ROA)


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