A general equation for the evaluation of the error that affects the value of the maximum specific growth rate

A general equation is proposed to evaluate the absolute error that affects the maximum specific growth rate calculated from batch or continuous experiments. This error depends on the relative errors of the cell concentration measurements and on the duration of the test.Nomenclature X ₁ Cell concentration at the beginning of the exponential growth phase or of the washing-out period - X ₁ Lowest value of X ₁ due to experimental errors - X ₁ Highest value of X ₁ due to experimental errors - X ₂ Cell concentration at the end of the exponential growth phse or of the washing-out period - X ₂ Lowest value of X ₂ due to experimental errors - X ₂ Highest value of X ₂ due to experiment errors - Relative error that affects X ₁ - Relative error that affects X ₂ - t Exponential growth stage or washing-out duration - Asolute error that affects - Maximum specific growth rate - ₁ Lowest value of due to experimental errors - ₂ Highest value of due to experimental errors The author is with the Instituto Mauá de Technologia, Estrada das Lágrimas 2035, 09580-900, São Caetano do Sul, SP, Brazil     

Hemoglobin vancouver [α2β2 73(E17) Asp→ Tyr]: Its structure and function

Summary Hemoglobin Vancouver is a new abnormal hemoglobin with an amino acid substitution of the normal aspartyl residue 73 of the chain by a tyrosyl residue. It was discovered in a man of Chinese descent in association with thalassemia. It was subsequently detected in a sister in association with normal Hb A. The oxygen affinity of the abnormal hemoglobin is decreased but its subunit interaction is normal. The Bohr effect may be slightly increased.This is the fourth abnormal hemoglobin to be found with a substitution at73. The others are Hb C-Harlem ( _{2 2} 6GluVal and 73 AspAsn), Hb Korle-Bu ( _{2 2} 73 AspAsn), and Hb Mobile ( _{2 2} 73 AspVal). Although Hb Mobile was found in the present studies to have a decreased affinity for oxygen, Hbs C-Harlem and Korle-Bu have been reported to be normal. These observations of functional differences for variants of73 added to earlier observations of the role of the normal73 residue to the aggregation of sickle deoxyhemoglobin indicate that this position of the molecule may be important in intra as well as intermolecular interactions.     

Soluble Expression and Affinity Purification of Functional Domain of Human Acetylcholine Receptor <Emphasis Type="Italic">α</Emphasis>-subunit by the Modulation of Maltose Binding Protein

An open reading frame of the -subunit 1-205 residues (₂₀₅) of human acetylcholine receptor (AchR) was amplified by PCR with pUC-AChR₂₀₅ as the template and inserted into vector pMAL-c2X. The constructed pMAR₂₀₅ was transferred into E. coli BL21 which were then grown in LB medium. The amount of soluble MBP-AChR₂₀₅ protein reached about 25% of total soluble proteins from the cell lysate. Using amylose-affinity chromatography, about 35 mg MBP-AChR₂₀₅ could be obtained from 1 l culture. Western blot analysis and ELISA showed that immunoreactivities of both MBP-AChR₂₀₅ and AChR₂₀₅ were similar to that of AChR -subunit from Torpedo.Revisions received 23 September 2004     

Kinetics of growth and lactic acid production in continuous and batch culture

Summary In a lactic acid fermentation by Streptococcus faecalis, the specific consumption rate of glucose (v) and the specific production rate of lactic acid () were represented by the following simple equations as functions of the specific growth rate (): 1/=(1/) + 1/ = (1/) + By use of data from a batch culture, these two equations were derived from enzyme kinetics of the product inhibition. These equations were successfully applied to the results of batch culture and chemostat culture. In addition, calculation of ATP yield by these equations agreed with the experimental results better than the conventional Leudeking-Piret type equation, which includes two terms associated with growth and not with growth. Correspondence to: H. Ohara     

Aflatoxin influences on seed germination and root elongation by two cultivars of Glycine max and uptake of 65 Zn-ZnCl2 by the cultivars

Maximum inhibition of Glycine max, cv. Essex seed germination occurred at 10 g/ml following 72 hr imbibition in constant light. Seeds imbided 108 hr in constant darkness at this concentration showed a 20% rise in germination over that of the control. Imbibition of G. max, cv. Williams seeds in either light or dark for 96 hr did not suppress germination. Imbibition of Essex seeds in either light or dark at 2.5 through 10 g/ml stimulated root elongation except for 10 g/ml at 96 hr (light). Maximum inhibition of Williams root elongation under constant light was at 48 and 72 hr with 10 g/ml. Statistically significant differences in cotyledon, leaf and stem lengths between non-treated (NT) and treated (T) seedlings were not found except for Williams stem length at 2.5 / ml. Root elongation was stimulated 1.2- and 1.1-folds, respectively, at 5.0 (Essex) and 2.5 (Williams) g/ml. Toxin at 2.5 through 10.0 g/ml did not markedly alter either cotyledon or leaf widths with the exception of Williams leaf width at 2.5 g/ml. Medium supplementation with 2.5 through 10.0 g/ml resulted in cotyledon, leaf and root weight enhancements for Essex seedlings. Stem weight was not markedly affected. An 18% rise in Williams cotyledon weight above that of the control was seen at 2.5 g/ml. Williams leaf weights were increased 1.75- and 1.25-folds, respectively, at 2.5 and 10.0 g/ml. Aflatoxin B₁, at 2.5 g/ml promoted Williams stem and root elongation 1.20- and 1.09-folds, respectively. Most of the radioactivity from ⁶⁵Zn-ZnCl₂ recovered within organs was found within Essex roots for both T and NT seedlings. A higher amount of radioactivity was recovered within roots at each toxin concentration than was without toxin. However, this was not statistically significant. Significant differences in the distribution of radioactivity within roots between NT and T Williams seedlings were not observed. Generally, AFB₁ failed to affect significantly these two varieties of soybeans based on the tests relating to germination, growth and radiolabel uptake.     

Control of glycoprotein synthesis: substrate specificity of rat liver UDP-GlcNAc:Manα3R β2-N-acetylglucosaminyl-transferase I using synthetic substrate analogues

UDP-GlcNAc: Man3R 2-N-acetylglucosaminyltransferase I (GlcNAc-T I; EC 2.4.1.101) is the key enzyme in the synthesis of complex and hybrid N-glycans. Rat liver GlcNAc-T I has been purified more than 25,000-fold (M _r 42,000). TheV _max for the pure enzyme with [Man6(Man3)Man6](Man3)Man4GlcNAc4GlcNAc-Asn as substrate was 4.6 µmol min^–1 mg^–1. Structural analysis of the enzyme product by proton nuclear magnetic resonance spectroscopy proved that the enzyme adds anN-acetylglucosamine (GlcNAc) residue in 1–2 linkage to the Man3Man-terminus of the substrate. Several derivatives of Man6(Man3)Man-R, a substrate for the enzyme, were synthesized and tested as substrates and inhibitors. An unsubstituted equatorial 4-hydroxyl and an axial 2-hydroxyl on the -linked mannose of Man6(Man3)Man-R are essential for GlcNAc-T I activity. Elimination of the 4-hydroxyl of the 3-linked mannose (Man) of the substrate increases theK _M 20-fold. Modifications on the 6-linked mannose or on the core structure affect mainly theK _M and to a lesser degree theV _max, e.g., substitutions of the Man6 residue at the 2-position by GlcNAc or at the 3- and 6-positions by mannose lower theK _M, whereas various other substitutions at the 3-position increase theK _M slightly. Man6(Man3)4-O-methyl-Man4GlcNAc was found to be a weak inhibitor of GlcNAc-T I.Abbreviations BSA Bovine serum albumin - Bn benzyl - Fuc, F l-fucose - Gal, G d-galactose - GalNAc, GA N-acetyl-d-galactosamine - Glc d-glucose - GlcNAc, Gn N-acetyl-d-glucosamine - HPLC high performance liquid chromatography - Man, M d-mannose - mco 8-methoxycarbonyl-octyl, (CH₂)₈ COOOCH₃ - Me methyl - MES 2-(N-morpholino)ethanesulfonate - NMR nuclear magnetic resonance - PMSF phenylmethylsulfonylfluoride - pnp p-nitrophenyl - SDS sodium dodecyl sulfate - T transferase - Tal d-talose - Xyl d-xylose; - {0, 2 + F} Man6 (GlcNAc2Man3) Man4GlcNAc4 (Fuc6) GlcNAc - {2, 2} GlcNAc2Man6 (GlcNAc2Man3) Man4GlcNAc4GlcNAc; M₅-glycopeptide, Man6 (Man3) Man6 (Man3) Man4 GlcNAc4GlcNAc-Asn Enzymes: GlcNAc-transferase I, EC 2.4.1.101; GlcNAc-transferase II, EC 2.4.1.143; GlcNAc-transferase III, EC 2.4.1.144; GlcNAc-transferase IV, EC 2.4.1.145; GlcNAc-transferase V, UDP-GlcNAc: GlcNAc2 Man6-R (GlcNAc to Man) 6-GlcNAc-transferase; GlcNAc-transferase VI, UDP-GlcNAc: GlcNAc6(GlcNAc2) Man6-R (GlcNAc to Man) 4-GlcNAc-transferase; Core 1 3-Gal-transferase, EC 2.4.1.122; 4-Gal-transferase, EC 2.4.1.38; 3-Gal-transferase, UDP-Gal: GlcNAc-R 3-Gal-transferase; blood group i 3-GlcNAc-transferase, EC 2.4.1.149; blood group I 6-GlcNAc-transferase, UDP-GlcNAc: GlcNAc3Gal-R (GlcNAc to Gal) 6-GlcNAc-transferase.     

Genetic analysis of resistance to whitebacked planthopper in twenty-one varieties of rice,Oryza sativa L.

Summary The inheritance of resistance to whitebacked planthopper Sogatella furcifera (Horvath) was studied in 21 rice varieties. Reactions of F₁; F₂ and F₃ progenies of the crosses of 21 resistant varieties with the susceptible variety TN 1 revealed that a single dominant gene governs resistance in Mushkan 41, Santhi, Siahnakidar 195, SM2-34, Tirisurkh 251, Zirijowaian 245, 18, 24A, 39, 76 S, 78, 180, 213 B, 267, 293, CI 6037-4, NP97, S39 JKW and Bansphul. In varieties 65 and 274 A, resistance is governed by one dominant and one recessive gene which segregate independently of each other. Tests for allelism with the Wbph 1 gene originally identified in N 22 revealed that the dominant gene present in all the test varieties is the same as Wbph 1. Further studies are required to determine the allelic relationships of the recessive gene found in varieties 65 and 274 A.     

Analysis of the effect of rye chromosomes 4R, 6R and telomeric heterochromatin on 7R on homologous chromosome pairing in pentaploid hybrids (AABBR,AABBD)

Summary Meiotic pairing in Triticum turgidum cv. Ma (4x) with a mean chiasmata frequency of 27.16 per cell was compared with chiasmata frequencies in its hybrids with several triticale strains, Chinese Spring wheat and its addition lines for Imperial rye chromosomes 4R and 6R. In hybrids between Ma and x Triticosecale cv. Rosner the chiasmata frequency was marginally reduced by an average of 1.25%, by 8.8% in hybrids with x Triticosecale cv. DRIRA HH and by 6.7% with DRIRA EE (lacking 90% telomeric heterochromatin from chromosome arm 7RL). In pentaploid hybrids between Ma and T. aestivum cv. Chinese Spring the reduction was an average of 10.30%, while addition lines with rye chromosome 6R reduced chiasmata frequencies by an average of 7.4% and rye addition line for 4R showed the greatest depression in chiasmata frequency in hybrids by a 25.04% reduction. An interchange difference involving long chromosome segments was observed between Ma and Rosner.Contribution No. 819 Ottawa Research Station     

Thermodynamics of Mn2+-binding to goat α-lactalbumin

By means of reaction calorimetry we measured the apparent enthalpy change, H^app, of the binding of Mn²⁺-ions to goat -lactalbumin as a function of temperature. The observed H^app can be written as the sum of contributions resulting from a conformational and a binding process. In combination with the thermal unfolding curve of goat -lactalbumin, we succeeded in separating the complete set of thermodynamic parameters (H, G, S, C_p) into the binding and conformational contributions. By circular dichroism we showed that NH ₄ ⁺ -ions, upon binding to bovine a-lactalbumin, induce the same conformational change as do Na⁺ and K⁺: the binding constant equals 98 ± 9 M^–1.Abbreviations BLA bovine -lactalbumin - GLA goat -lactalbumin - HLA human -lactalbumin - CD circular dichroism Offprint requests to: H. Van DaelDeceased     

The energy transmission in ATP synthase: From the γ-c rotor to the α3β3 oligomer fixed by OSCP-b stator via the βDELSEED sequence

ATP synthase (F₀F₁) is driven by an electrochemical potential of H⁺ (H⁺). F₀F₁ is composed of an ion-conducting portion (F₀) and a catalytic portion (F₁). The subunit composition of F₁ is ₃₃. The active ₃₃ oligomer, characterized by X-ray crystallography, has been obtained only from thermnophilic F₁ (TF₁). We proposed in 1984 that ATP is released from the catalytic site (C site) by a conformational change induced by the DELSEED sequence via -F₀. In fact, cross-linking of DELSEED to stopped the ATP-driven rotation of in the center of ₃₃. The torque of the rotation is estimated to be 420 pN·å from the H⁺ and H⁺-current through F₀F₁. The angular velocity () of is the rate-limiting step, because H⁺ increased theV _max of H⁺ current through F₀, but not theK _m (ATP). The rotational unit of F₀ (=ab₂c₁₀) is /5, while that in ₃₃ is 2/3. This difference is overcome by an analog-digital conversion via elasticity around DELSEED with a threshold to release ATP. The distance at the C site is about 9.6 å (2,8-diN₃-ATP), and tight Mg-ATP binding in ₃₃ was shown by ESR. The rotational relaxation of TF₁ is too rapid (=100 nsec), but the rate of AT(D)P-induced conformational change of ₃₃ measured with a synchrotron is close to . The ATP bound between the P-loop and E188 is released by the shift of DELSEED from RGL. Considering the viscosity resistance and inertia of the free rotor (-c), there may be a stator containing OSCP (= of TF₁) and F₀-d to hold free rotation of ₃₃.     

Inheritance of seed α-amylase inhibitor in the common bean and genetic relationship to arcelin

The inheritance of seed -amylase inhibitor in the common bean and the genetic relationships among the variants and six arcelin variants in the common bean were investigated by crossing between accessions containing different AI and arcelin variants. All seed proteins in parental, F₁ and F₂ seeds from the crosses were examined by Western-blot analysis. All F₁ seeds gave combined AI banding patterns from parents on the blotting membranes. The segregation of F₂ seeds for AI variants indicated that the polypeptides of AI variants were inherited as single co-dominant units. Moreover, AI and arcelin behaved as a single block in crosses, indicating a close linkage relationship between the genes controlling these proteins.     

Differential effects of foods traditionally regarded as ‘heating’ and ‘cooling’ on prostaglandin E2 production by a macrophage cell line

Some components of natural foods may enhance or inhibit prostaglandin formation and potentially affect the inflammation condition. A macrophage cell line, RAW264.7, was employed to examine the effects of foods traditionally regarded as heating or cooling on the production of PGE₂, a well-known proinflammatory mediator. Foods traditionally regarded as heating (litchi, longan, and dried longan) or cooling (chrysanthemum flower, bitter gourd, and lotus seed plumule) were extracted sequentially with water and ethyl acetate. The water extracts (WE) and ethyl acetate extracts (EAE) were applied to RAW264.7 macrophages in the presence or absence of LPS (lipopolysaccharide). In the absence of LPS, the WEs from the heating foods, litchi, longan, or dried longan had a dose-dependent enhancing effect on PGE₂ production, with respective EC₅₀s of 8.4, 16, and 11 mg/ml. This effect was accompanied by significant induction of COX-2 protein expression, as shown by Western blot analysis. In contrast, LPS-induced PGE₂ production was inhibited in a dose-dependent manner by the WEs of the cooling foods, chrysanthemum flower, bitter gourd, and lotus seed plumule, with respective IC₅₀s of 0.6, 0.13, and 0.08 mg/ml. At the concentrations tested, none of the EAEs had any effect on basal PGE₂ production, while LPS-induced PGE₂ production was inhibited or increased by the EAE from bitter gourd and longan, respectively. Water-soluble extracts of foods traditionally regarded as heating enhanced basal PGE₂ production, while those from cooling foods significantly inhibited LPS-induced PGE₂ production by the macrophage cell line. This subject merits further study to determine whether appropriate food selection may help patients suffering from chronic inflammatory conditions.     

On morphological variation in Keratella cochlearis populations from Holstein lakes (Northern Germany)

Keratella cochlearis occurs in many Holstein lakes (northern Germany) as three well defined and separated forms: cochlearis, hispida, and tecta, each showing very little variation between the lakes. The present data show that the tecta form did not originate from a Lauterborn cycle.     

Early generation intermating for yield improvement in groundnut (Arachis hypogaea L.)

Summary Seeds of 4 crosses of groundnut (Arachis hypogaea L.), Robut 33-1 x Chico, Robut 33-1 x NC Ac 17090, Robut 33-1 x PI 298115 and MK 374 x GAUG 1, were irradiated with 30 kR. In the F₁, some branches of each plant were intermated with other plants at random and others selfed in each cross to produce S₂ and F₂ seeds. They were evaluated for pod yield, shelling percentage and 100-kernel weight. The frequency of plants superior to F[in1] was much higher in S₂ than in F₂, which was, in general, true for the values of yield and its components. The S₂ and F₂ were advanced to third generation by selfing. The families descending from S₂ showed clear superiority over those from F₂. The reason for such superiority was suggested to be the recombination of genes from the upper and lower ends of the genotypic distribution under intermating.     

The catalysis of nucleotide polymerization by compounds of divalent lead

Summary Soluble lead salts and a number of lead-containing minerals catalyze the formation of oligonucleotides from nucleoside 5-phosphorimidazolides. The effectiveness of lead compounds correlates strongly with their solubility. Under optimal conditions we were able to obtain 18% of pentamer and higher oligomers from ImpA. Reactions involving ImpU gave smaller yields.Abbreviations A adenosine - U uridine - Im imidazole - MeIm 1-methyl-imidazole - EDTA ethylenediaminetetraacetic acid - pA adenosine 5-phosphate - pU uridine 5-phosphate - Ap adenosine cyclic 2:3-phosphate - ATP adenosine 5-triphosphate - AppA P₁,P₂-diadenosine 5-diphosphate - pNp (N = A,U) nucleotide 2(3), 5-diphosphate - ImpA adenosine 5-phosphoreimidazolide - ImpU uridine 5-phosphorimidazolide - A ²pA adenylyl-[25]-adenosine - A ³pA adenylyl-[35]-adenosine - pA ²pA 5-phospho-adenylyl-[25]-adenosine - pA ³pA 5-phospho-adenylyl-[35]-adenosine - pUpU 5-phospho-uridylyl-uridine - pApU 5-phospho-adenylyl-uridine - pUpA 5-phospho-uridylyladenine - (pA)n (n, 2,3,4,) oligoadenylates with 5 terminal phosphate - ImpApA 5-phosphorimidazolide of adenylyl adenosine - (pA) ₅₊ pentamer and higher oligoadenylates with 5 terminal phosphate - (Ap)nA (n = 2,3,4) oligoadenylates without terminal phosphates In the following we do not specify the nature of the internucleotide linkageIn the following we do not specify the nature of the internucleotide linkage     

Production of a novel syrup containing neofructo-oligosaccharides by the cells of Penicillium citrinum

A novel syrup containing neofructo-oligosaccharides was produced from sucrose (Brix 70) by whole cells of Penicillium citrinum. The efficiency of fructo-oligosaccharides production was more than 55% and those of the main carbohydrate components, 1-kestose (Fruf 21Fruf 21 Glc), nystose (Fruf 21Fruf 21 Fruf 21 Glc) and neokestose (Fruf 26 Glc12 Fruf), were 22, 14 and 11%, respectively.     

Ganglioside lactones:1H-NMR determination of the inner ester position of GD1b-ganglioside lactone naturally occurring in human brain or produced by chemical synthesis

The complete definition of the chemical structure of G_D1b-ganglioside (G_D1b) lactone isolated from human brain has been given by means of spectrometric and spectroscopic analyses. G_D1h lactone contains a single ester linkage involving the external sialic acid carboxyl group and the C-9 hydroxyl group of the internal sialic acid unit. A synthetic lactone of G_D1b prepared treating G_D1b with glacial acetic acid characterized in the same way showed an identical chemical structure.Abbreviations: Ganglioside nomenclature is according to Svennerholm [16] and the IUPAC-IUB Recommendations [17] G_M1 G_M1-ganglioside, II³NeuAc-GgOse₄Cer, Gal1-3GalNac1-4[NeuAc2-3]Gal1-4Glc1-1Cer - G_D1b G_D1b-ganglioside, II³(NeuAc)₂GgOse₄Cer, Gal1-3GalNAc1-4[NeuAc2-8NeuAc2-3]Gal1-4Glc1-1Cer - G_D1b lactone G_D1b-L, Gal1-3GalNAc1-4[NeuAc(1-9)2-8NeuAc2-3]Gal1-4Glc1-1Cer - Cer ceramide - FAB-MS fast atom bombardment-mass spectrometry - ¹H-NMR proteon nuclear magnetic resonance - 1D-NMR one dimensional NMR - 2D-COSY two dimensional correlated spectroscopy - DMSO-d₆ deuterated dimethylsulfoxide     

Effect of giving insulin and adrenalin alternately on changes in the level of blood glucose in chickens of different breeds

Summary Differences in reaction to exogenous insulin and adrenalin were studied among chickens of Leghorn, White Rock and Rhode Island Red breeds, using level of blood glucose as indicator of the reaction to hormones. It was found that: 1.) The physiological quantity of glucose in blood in chickens of the three breeds ranged from 157 to 194 mg %. 2.) The reaction of chickens to insulin and adrenalin given alternately, measured by changes of blood glucose, differed according to the breed. The smallest reaction to hormones was in Leghorn, the biggest in White Rock. 3.) The chickens of Leghorn and Rhode Island Red breeds, as well as Leghorn and White Rock breeds, differed significantly in maximal glucose level after adrenalin, 4.) The correlation between the normal quantity of blood glucose and the body weight of birds appeared highly significant in cockerels of all three races combined.     

"Velocity leakage" in the pigeon vestibulo-ocular reflex

The transfer characteristics of the vestibuloocular reflex (VOR), and of the semicircular canal primary afferents (SCPAs) that drive it, have been studied in several species. In monkeys and cats, the dominant time constant describing horizontal VOR dynamics ( _hu ) is longer than that ( _c ) of horizontal SCPAs. This lengthening of the time constant has been attributed to a velocity storage mechanism that has been modeled as a positive feedback loop in the VOR pathways. We have studied the transfer characteristics of horizontal and vertical VOR and SCPAs in unanesthetized pigeons. In this species the dominant time constants of both the horizontal and vertical VOR ( _hv and _vv ) are shorter than _c . This finding indicates that time constants characterizing the lower frequency response of the VOR can be lengthened or shortened depending on the species. We propose that in the pigeon the velocity leakage mechanism can be modeled by substituting negative feedback for positive feedback in the model of the VOR pathways. Negative feedback can also account for the further shortening of _hu and _vv as VOR gain increases with arousal. Additionally, making the negative feedback loop nonlinear can model the dependency of lower frequency VOR phase on amplitude, and skew in VOR waveforms. Pigeon VOR and SCPA dynamics also differ in their adaptive properties and higher frequency behavior. A predominance of input from highly adaptive SCPAs is proposed to account for the increased adaptation of the vertical VOR as compared with SCPAs overall. A pure time-delay associated with VOR operation can explain the phase lag of the VOR relative to SCPAs at higher frequencies.     

Confidence interval estimators for heritability for several mating and experiment designs

Summary Confidence interval estimators have not been described for several heritability (H) estimators relevant to recurrent family selection. Previously described H interval estimators do not apply to onefactor mating designs in split-plot in time experiment designs in one or more locations, one-factor mating designs for several experiment designs in two or more locations and years, and two-factor mating designs for several experiment designs in two or more locations or years. Our objective was to derive H interval estimators for these cases. H reduced to a function of constants and a single expected mean square ratio in every case; H=1–E(M)/E(M) where E(M) is a linear function of expected mean squares and E(M) is a single expected mean square. It was shown that F=[M/E(M)]/[M/E(M)] has an approximate F-distribution with df and df degrees of freedom, respectively, where M and M are mean squares corresponding to E(M) and E(M), respectively. H is a function of F, therefore, we used F to define an approximate (1–) interval estimator for H.Oregon Agricultural Experiment Station Technical Paper No. 7923