A comparison of quantitative methods for measuring yeast flocculation

1977 ◽  
Vol 23 (1) ◽  
pp. 68-74 ◽  
Author(s):  
G. B. Calleja ◽  
Byron F. Johnson

Two quantitative objective methods for measuring flocculation of a yeast culture were com pared and correlated with subjective estimation by eye. One method involved counting in a haemocytometer the number of free cells (i.e., cells not found in flocs) and then the total number of cells after complete deflocculation by pronase. The number of cells in flocs was derived by subtracting the number of free cells from the total number of cells. The other method made use of the decrease in turbidity of a flocculated culture on standing. Gross flocs settled to the bottom of a tube within 5 min. The decrease in turbidity was measured by a photoelectric colorimeter. The difference in turbidity readings between 0 and 5 min was assumed to represent the turbidity component due to cells in flocs. The methods were appropriately applicable to monitoring the time course of sex-directed flocculation of the fission yeast Schizosaccharomyces pombe. A culture at maximum flocculation contained 500 gross flocs ml−1 which represented up to 70% of the total number of cells. A typical primary floc occupied a volume of 1 × 10−4 ml and contained 1 × 105 cells.

1995 ◽  
Vol 05 (04) ◽  
pp. 255-264 ◽  
Author(s):  
ITSURO TAMANOI ◽  
AKEMI NAKAMURA ◽  
KIYOFUSA HOSHIKAWA ◽  
MUTSUMI KACHI ◽  
KUNIO OOHASHI ◽  
...  

The quantitative changes in the elements, amounts of Cl, K, Ca, in blood plasma were measured by PIXE method. The samples were obtained at appropriate intervals after transplantation of EL-4 tumor cells in three strains of mice, C57BL/6J (H-2b), C57BL/10J (abbreviation: B10; H-2b) and A/J (H-2a). Transplanted EL-4 tumor cells proliferated in both strains of C57BL/6J and B10. In A/J mice, transplanted EL-4 cells proliferated about 10 days and then were rejected completely by the immunological reaction according to the difference of major histocompatibility antigens. The amounts of Cl in plasma remained at similar level in the time course in any strains, but K fluctuated in C57BL/6J and B10, and less in A/J. On the other hand, Ca showed always higher values in C57BL/6J than other two strains of mice. In B10 mice, Ca increased just before death, but in A/J it decreased at the time of healing by rejection. These changes of Ca in the three strains of mice were related quantitatively 10 the hematocrit values of these strains of mice after transplantation of EL-4 cells.


1994 ◽  
Vol 77 (4) ◽  
pp. 1991-1998 ◽  
Author(s):  
R. C. Kolbeck ◽  
T. M. Nosek

Muscle fatigue was studied in the isolated perfused rat (66% oxidative fibers) and mouse (99% oxidative fibers) diaphragms. Both muscles displayed two fatigue patterns when exposed to 333-ms trains of 20-Hz stimulation. A rapid fatigue pattern appeared within each contractile train as an immediate progressive twitch-by-twitch diminution in contractility [a decrease in maximal isometric twitch tension (T) and maximal rate of T development]. An intertrain slow fatigue pattern also appeared as a progressive train-by-train diminution in contractility and an increased maximal rate of relaxation normalized to T. A reduction in the stimulatory frequency from 20 to 2 Hz caused a considerable diminution in the rapid fatigue pattern. These data suggest that rapid fatigue results from the time course of mechanical restitution, the time necessary for the Ca2+ channels of the sarcoplasmic reticulum to recover from inactivation. The slow fatigue pattern, on the other hand, is thought to be due to changes in the intracellular milieu. The difference in sensitivity of the rat and mouse diaphragms to rapid and slow fatigue is apparently related to differences in their fiber type composition. Thus, as would be expected, the mouse diaphragm, composed of only oxidative fibers, is less susceptible to slow fatigue compared with the rat diaphragm. On the other hand, it is more susceptible to rapid fatigue.


Author(s):  
P. Maupin-Szamier ◽  
T. D. Pollard

We have studied the destruction of rabbit muscle actin filaments by osmium tetroxide (OSO4) to develop methods which will preserve the structure of actin filaments during preparation for transmission electron microscopy.Negatively stained F-actin, which appears as smooth, gently curved filaments in control samples (Fig. 1a), acquire an angular, distorted profile and break into progressively shorter pieces after exposure to OSO4 (Fig. 1b,c). We followed the time course of the reaction with viscometry since it is a simple, quantitative method to assess filament integrity. The difference in rates of decay in viscosity of polymerized actin solutions after the addition of four concentrations of OSO4 is illustrated in Fig. 2. Viscometry indicated that the rate of actin filament destruction is also dependent upon temperature, buffer type, buffer concentration, and pH, and requires the continued presence of OSO4. The conditions most favorable to filament preservation are fixation in a low concentration of OSO4 for a short time at 0°C in 100mM sodium phosphate buffer, pH 6.0.


1973 ◽  
Vol 29 (02) ◽  
pp. 490-498 ◽  
Author(s):  
Hiroh Yamazaki ◽  
Itsuro Kobayashi ◽  
Tadahiro Sano ◽  
Takio Shimamoto

SummaryThe authors previously reported a transient decrease in adhesive platelet count and an enhancement of blood coagulability after administration of a small amount of adrenaline (0.1-1 µg per Kg, i. v.) in man and rabbit. In such circumstances, the sensitivity of platelets to aggregation induced by ADP was studied by an optical density method. Five minutes after i. v. injection of 1 µg per Kg of adrenaline in 10 rabbits, intensity of platelet aggregation increased to 115.1 ± 4.9% (mean ± S. E.) by 10∼5 molar, 121.8 ± 7.8% by 3 × 10-6 molar and 129.4 ± 12.8% of the value before the injection by 10”6 molar ADP. The difference was statistically significant (P<0.01-0.05). The above change was not observed in each group of rabbits injected with saline, 1 µg per Kg of 1-noradrenaline or 0.1 and 10 µg per Kg of adrenaline. Also, it was prevented by oral administration of 10 mg per Kg of phenoxybenzamine or propranolol or aspirin or pyridinolcarbamate 3 hours before the challenge. On the other hand, the enhancement of ADP-induced platelet aggregation was not observed in vitro, when 10-5 or 3 × 10-6 molar and 129.4 ± 12.8% of the value before 10∼6 molar ADP was added to citrated platelet rich plasma (CPRP) of rabbit after incubation at 37°C for 30 second with 0.01, 0.1, 1, 10 or 100 µg per ml of adrenaline or noradrenaline. These results suggest an important interaction between endothelial surface and platelets in connection with the enhancement of ADP-induced platelet aggregation by adrenaline in vivo.


2014 ◽  
Vol 1 (1) ◽  
pp. 47-56
Author(s):  
Milan Palat

Bu çalışmanın amacı, Türkiye’den göç ve Almanya’nın ekonomik göstergeleri arasındaki ilişkiyi, nicel metot yöntemleri kullanarak değerlendirmektir. Türkiye’nin belirsiz Avrupa ile bütünleşme beklentilerine rağmen  Avrupa Birliğinin köklü üyelerine olan Türk göçü devam edecektir. Çok sayıda Türk azınlığın yaşadığı ve hayat standartlarının yüksek olduğu Almanya, Hollanda ve Fransa’ya  büyük bir göç dalgası gerçekleşebilir. Çalışmanın istatistiksel bölümünün sonuçları, toplam göç ile gayri safi yurtiçi hasıladaki büyüme arasında pozitif, toplam göç ile işsizlik arasındaki negatif ve tahmin edilen bağımlılık yönüyle uygunluk içerisinde olan toplam göç ile aylık gelir arasında pozitif ilişki olduğunu göstermektedir. Türkiye’den göçle işsizlik arasındaki ilişki, toplam göçle olan ilişkiden daha düşüktür. Ancak, Almanya’daki yabancı mevcudiyeti ile Türkiye’den göç arasında bir ilişki bulunmaktadır. Bu durum, var olan göçmen topluluğunun olduğu yerin, yeni göçmenleri, köken bağlarına dayanarak cezbetmesi ve maliyet- riskler sebebiyle göçün düşük seviye de olduğuna dayanan kuramsal Ağ teorisi görüşü ile uygunluk göstermektedir. Göç ve işsizlik arasında gözlenen ilişki, Almanya’ya göçün  işgücü piyasasında talepte meydana gelen değişime karşılık geldiği gerçeğini göstermektedir. İşsizlik ve göç olgularının meydana geliş zamanlarında bir aralık  olsa bile  göç, Alman emek pazarında var olan dengesizliklerin azaltılmasında nispeten etkili bir mekanizma gibi görünmektedir. ENGLISH TITLE & ABSTRACTTurkish Immigration to the European Union: The Case of GermanyThe objective of the paper was to evaluate the relationships between immigration from Turkey and economic indicators in Germany using  quantitative methods. Despite Turkey’s unclear European integration prospects, it is predicted that Turkish immigration to  established member countries of the EU will continue. The strongest waves may flow to Germany, Netherlands or France, where numerous Turkish minorities are already present and where the living standards are high. Results from the statistical analysis of the paper showed a positive correlation between immigration total and the growth of gross domestic product. On the other hand, a negative correlation of immigration total and unemployment was found and a positive relationship between immigration total and income total which is in agreement with the expected dependency direction. With regards to  immigration from Turkey it is less correlated to unemployment than immigration total. But there is a correlation between immigration from Turkey and the stock of foreigners in Germany This is in accordance with the theoretical concept of network theory where an existing community of migrants keeps attracting new migrants because the costs and risks associated with migration are lower, thanks to established linkages to the country of origin. The observed correlation of migration and unemployment points to the fact that immigration to Germany responds to changes in demand in the labour market. Even though a time lag may occur in the case of unemployment and immigration, migration appears to be a relatively effective mechanism to offset existing imbalances in German labour markets. 


Author(s):  
Philip Isett

This chapter presents the equations and calculations for energy approximation. It establishes the estimates (261) and (262) of the Main Lemma (10.1) for continuous solutions; these estimates state that we are able to accurately prescribe the energy that the correction adds to the solution, as well as bound the difference between the time derivatives of these two quantities. The chapter also introduces the proposition for prescribing energy, followed by the relevant computations. Each integral contributing to the other term can be estimated. Another proposition for estimating control over the rate of energy variation is given. Finally, the coarse scale material derivative is considered.


Metahumaniora ◽  
2017 ◽  
Vol 7 (3) ◽  
pp. 378
Author(s):  
Vincentia Tri Handayani

AbstrakFolklor yang menghasilkan tradisi lisan merupakan perwujudan budaya yang lahirdari pengalaman kelompok masyarakat. Salah satu bentuk tradisi lisan adalah ungkapan yangmengandung unsur budaya lokal dalam konstruksinya yang tidak dimiliki budaya lainnya.Ungkapan idiomatis memberikan warna pada bahasa melalui penggambaran mental. Dalambahasa Perancis, ungkapan dapat berupa locution dan expression. Perbedaan motif acuansuatu ungkapan dapat terlihat dari pengaruh budaya masyarakat pengguna bahasa. Sebuahleksem tidak selalu didefinisikan melalui unsur minimal, tidak juga melalui kata-kata,baik kata dasar atau kata kompleks, namun dapat melalui kata-kata beku yang maknanyatetap. Hubungan analogis dari makna tambahan yang ada pada suatu leksem muncul dariidentifikasi semem yang sama. Semem tersebut mengarah pada term yang diasosiasikan danyang diperkaya melalui konteks (dalam ungkapan berhubungan dengan konteks budaya).Kata kunci: folklor, ungkapan, struktur, makna idiomatis, kebudayaanAbstractFolklore which produces the oral tradition is a cultural manifestation born out theexperience of community groups. One form of the oral tradition is a phrase that containsthe elements of local culture in its construction that is not owned the other culture. Theidiomatic phrase gives the color to the language through the mental representation. InFrench, the expression can consist of locution and expression. The difference motivesreference of an expression can be seen from the influence of the cultural community thelanguage users. A lexeme is not always defined through a minimal element, nor throughwords, either basic or complex words, but can be through the frost words whose meaningsare fixed. The analogical connection of the additional meanings is on a lexeme arises fromthe identification of the same meaning. The meaning ‘semem’ leads to the associated termsand which are enriched through the context (in idiom related to the cultural context).Keywords : folklore, idioms, structure, idiom meaning, cultureI PENDAHULUAN


2017 ◽  
Vol 1 (2) ◽  
pp. 137
Author(s):  
Noorlela Binti Noordin ◽  
Abdul Razaq Ahmad ◽  
Anuar Ahmad

This study was aimed to evaluate the Malay proficiency among students in Form Two especially non-Malay students and its relationship to academic achievement History. To achieve the purpose of the study there are two objectives, the first is to look at the difference between mean of Malay Language test influences min of academic achievement of History subject among non-Malay students in Form Two and the second is the relationship between the level of Malay proficiency and their academic achievement for History. This study used quantitative methods, which involved 100 people of Form Two non-Malay students in one of the schools in Klang, Selangor. This study used quantitative data were analyzed using descriptive statistics and statistical inference with IBM SPSS Statistics v22 software. This study found that there was a relationship between the proficiency of Malay language among non-Malay students with achievements in the subject of History. The implications of this study are discussed in this article.


Author(s):  
Michel Meyer

Rhetoric has always been torn between the rhetoric of figures and the rhetoric of conflicts or arguments, as if rhetoric were exclusively one or the other. This is a false dilemma. Both types of rhetoric hinge on the same structure. A common formula is provided in Chapter 3 which unifies rhetoric stricto sensu and rhetoric as argumentation as two distinct but related strategies adopted according to the level of problematicity of the questions at stake, thereby giving unity to the field called “Rhetoric.” Highly problematic questions require arguments to justify their answers; non-divisive ones can be treated rhetorically through their answers as if they were self-evident. Another classic problem is how to understand the difference between logic and rhetoric. The difference between the two is due to the presence of questions explicitly answered in the premises in logic and only suggested (or remaining indeterminate) in rhetoric.


Author(s):  
D. T. Gauld ◽  
J. E. G. Raymont

The respiratory rates of three species of planktonic copepods, Acartia clausi, Centropages hamatus and Temora longicornis, were measured at four different temperatures.The relationship between respiratory rate and temperature was found to be similar to that previously found for Calanus, although the slope of the curves differed in the different species.The observations on Centropages at 13 and 170 C. can be divided into two groups and it is suggested that the differences are due to the use of copepods from two different generations.The relationship between the respiratory rates and lengths of Acartia and Centropages agreed very well with that previously found for other species. That for Temora was rather different: the difference is probably due to the distinct difference in the shape of the body of Temora from those of the other species.The application of these measurements to estimates of the food requirements of the copepods is discussed.


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