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1.
This study was designed to investigate the relationship between the microclimate temperature and clothing insulation (Icl) under comfortable environmental conditions. In total, 20 subjects (13 women, 7 men) took part in this study. Four environmental temperatures were chosen: 14°C (to represent March/April), 25°C (May/June), 29°C (July/August), and 23°C (September/October). Wind speed (0.14ms-1) and humidity (45%) were held constant. Clothing microclimate temperatures were measured at the chest (Tchest) and on the interscapular region (Tscapular). Clothing temperature of the innermost layer (Tinnermost) was measured on this layer 30 mm above the centre of the left breast. Subjects were free to choose the clothing that offered them thermal comfort under each environmental condition. We found the following results. 1) All clothing factors except the number of lower clothing layers (Llower), showed differences between the different environmental conditions (P<0.05). The ranges of Tchest were 31.6 to 33.5°C and 32.2 to 33.4°C in Tscapular. The range of Tinnermost was 28.6 to 32.0°C. The range of the upper clothing layers (Lupper) and total clothing mass (Mtotal) was 1.1 to 3.2 layers and 473 to 1659 g respectively. The range of Icl was 0.78 to 2.10 clo. 2) Post hoc analyses showed that analysis of Tinnermost produced the same results as for that of Icl. Likewise, the analysis of Lupper produced the same result as the analysis of the number of total layers (Ltotal) within an outfit. 3) Air temperature (ta) had positive relationships with Tchest and Tscapular and with Tinnermost but had inverse correlations with Icl, Mtotal, Lupper and Ltotal. Tchest, Tscapular, and Tinnermost increased as ta rose. 4) Icl had inverse relationships with Tchest and Tinnermost, but positive relationships with Mtotal, Lupper and Ltotal. Icl could be estimated by Mtotal, Lupper, and Tscapular using a multivariate linear regression model. 5) Lupper had positive relationships with Icl and Mtotal, but Llower did not. Subjects hardly changed Llower under environmental comfort conditions between March and October. This indicates that each of the Tchest, Mtotal, and Lupper was a factor in predicting Icl. Tinnermost might also be a more influential factor than the clothing microclimate temperature.  相似文献   

2.
1. Evolutionary changes in the structure of an enzyme that provide an increase in its Km value are considered. Provided that Km increases as a result of increases in the forward rate constants of the catalysis relative to the reverse rate constants, the enzyme catalyses the conversion of a fixed concentration of its substrate more rapidly when its structure provides that Km>[S] than when Km<[S]. 2. Catalytic efficiency of enzymes is discussed in terms of the simplest plausible model, the Haldane [(1930) Enzymes, Longmans, London] reversible three-step model: [Formula: see text] The rate equation for the forward reaction of this model (formation of P) may be written in the simple form: [Formula: see text] Keq. is the equilibrium constant (=[P]eq./[S]eq.), and kcat.=V/[E]T, where [E]T is the total enzyme concentration. 3. To assess the effectiveness of an enzyme, it is necessary only to determine the extent to which the constraints of a particular kinetic mechanism permit v2 (v when Km»[S]) to approach vd (the diffusion-limited rate). 4. The value of the optimal rate of catalysis (vopt., the maximal value of v2) is dictated by the equilibrium constant for the reaction, Keq.; v2=vd/a, where [Formula: see text] when k+1 is assumed equal to k−3, and vopt.=vd/amin.. When Keq.≥1, it is necessary that k+2»k−1 for a to take its minimum value, amin.; when Keq.«1, it is necessary only that k+2»Keq.·k−1, i.e. a can equal amin. even if k+2<k−1. When Keq.»1, vopt.=vd; when Keq.=1, vopt.=vd/2, and when Keq.«1, vopt.=Keq.·vd. 5. The analysis, together with predicted effects of evolutionary pressure, suggests that in practice the rates of the fastest enzyme-catalysed freely reversible reactions might be expected to be lower than the value of k+1[E]T[S] by about an order of magnitude, particularly if Keq.<1. 6. The existing literature suggests that, in general, appropriate values of Km have evolved for the provision of high rates of catalysis but that many values of kcat. are not large enough to provide optimal rates of catalysis unless the value of k+1 in vivo is lower than its value in free solution.  相似文献   

3.
Energetics of Active Transport Processes   总被引:13,自引:3,他引:10       下载免费PDF全文
Discussions of active transport usually assume stoichiometry between the rate of transport J+ and the metabolic rate Jr. However, the observation of a linear relationship between J+ and Jr does not imply a stoichiometric relationship, i.e., complete coupling. Since coupling may possibly be incomplete, we examine systems of an arbitrary degree of coupling q, regarding stoichiometry as a limiting case. We consider a sodium pump, with J+ and Jr linear functions of the electrochemical potential difference, -X+, and the chemical affinity of the metabolic driving reaction, A. The affinity is well defined even for various complex reaction pathways. Incorporation of a series barrier and a parallel leak does not affect the linearity of the composite observable system. The affinity of some region of the metabolic chain may be maintained constant, either by large pools of reactants or by regulation. If so, this affinity can be evaluated by two independent methods. Sodium transport is conveniently characterized by the open-circuit potential (Δψ)I=0 and the natural limits, level flow (J+)X+=0, and static head X0+ = (X+)J+=0. With high degrees of coupling -X0+/F approaches the electromotive force ENa (Ussing); -X0+/F cannot be identified with ((RT/F) ln f)X+=0, where f is the flux ratio. The efficiency η = -J+X+/JrA is of significance only when appreciable energy is being converted from one form to another. When either J+ or -X+ is small η is low; the significant parameters are then the efficacies εJ+ = J+/JrA and εX+ = -X+/JrA, respectively maximal at level flow and static head. Leak increases both J+ and εJ+ for isotonic saline reabsorption, but diminishes -X0+ and εX. Electrical resistance reflects both passive parameters and metabolism. Various fundamental relations are preserved despite coupling of passive ion and water flows.  相似文献   

4.
Peter R. Rich  Derek S. Bendall 《BBA》1980,591(1):153-161
1. In fresh chloroplasts, three b-type cytochromes exist. These are b-559HP (λmax, 559 nm; Em at pH 7, +370 mV; pH-independent Em), b-559LP (λmax, 559 nm; Em at pH 7, +20 mV; pH-independent Em) and b-563 (λmax, 563 nm; Em at pH 7, ?110 mV; pH-independent Em). b-559HP may be converted to a lower potential form (λmax, 559 nm; Em at pH 7, +110 mV; pH-independent Em).2. In catalytically active b-f particle preparations, three cytochromes exist. These are cytochrome f (λmax, 554 nm; Em at pH 7, +375 mV, pK on oxidised cytochrome at pH 9), b-563 (λmax, 563 nm; Em at pH 7, ?90 mV, small pH-dependence of Em) and a b-559 species (λmax, 559 nm, Em at pH 7, +85 mV; pH-independent Em).3. A positive method of demonstration and estimation of b-559LP in fresh chloroplasts is described which involves the use of menadiol as a selective reductant of b-559LP.  相似文献   

5.
The rapidly inactivating (INaf) and noninactivating Na+ currents (INa(NI)) were characterized in NG108-15 neuronal cells differentiated with dibutyryl cyclic AMP in this study. Standard activation and inactivation protocols were used to evaluate the steady-state and kinetic properties of the INaf present in these cells. The voltage protocols with a slowly depolarizing ramp were implemented to examine the properties of INa(NI). Based on experimental data and computer simulations, a window component of the rapidly inactivating sodium current (INaf(W)) was also generated in response to the slowly depolarizing ramp. The INaf(W) was subtracted from INa(NI) to yield the persistent Na+ current (INa(P)). Our results demonstrate the presence of INa(P) in these cells. In addition to modifying the steady-state inactivation of INaf, ranolazine or riluzloe could be effective in blocking INaf(W) and INa(P). The ability of ranolazine and riluzole to suppress INa(P) was greater than their ability to inhibit INaf(W). In current-clamp recordings, current-induced voltage oscillations were applied to elicit action potentials (APs) through a gradual transition between spontaneous depolarization and upstroke. Ranolazine or riluzole at a concentration of 3 μM then effectively suppressed the AP firing generated by oscillatory changes in membrane current. The data suggest that a small rise in INa(NI) facilitates neuronal hyper-excitability due the decreased threshold of AP initiation. The underlying mechanism of the inhibitory actions of ranolazine or riluzole on membrane potential in neurons or neuroendocrine cells in vivo may thus be associated with their blocking of INa(NI).  相似文献   

6.
Mesophyll conductance (g m) is essential to determine accurate physiological parameters used to model photosynthesis in forest ecosystems. This study aimed to determine the effects of time of day on photosynthetic parameters, and to assess the effect of using either intercellular CO2 concentration (C i) or chloroplast CO2 concentration (C c), on maximum carboxylation velocity of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), V cmax. We used Amazonian saplings of Myrcia paivae and Minquartia guianensis. Photosynthetic parameters were measured using an infrared gas analyzer (IRGA); g m was determined using both gas exchange and chlorophyll (Chl) a fluorescence and gas-exchange data alone. Leaf thickness (L T) and specific leaf area (SLA) were also measured. Air temperature, relative humidity or understory light did not correlate with g m and on average daily IRGA-fluorometer-determined g m was 0.04 mol(CO2) m?2 s?1 for M. paivae and 0.05 mol(CO2) m?2 s?1 for M. guianensis. Stomatal conductance (g s), g m, electron transport rate (J F), and light-saturated net photosynthetic rate (P Nmax) were lower in the afternoon than in the morning. However, no effect of time of day was observed on V cmax. L T and SLA did not affect any of the examined parameters. IRGA-determined g m was almost the double of the value obtained using the IRGA-fluorescence method. V cmax values determined using C c were about 25% higher than those obtained using C i, which highlighted the importance of using C c in V cmax calculation. Decline in P Nmax at the end of the afternoon reflected variations in g s and g m rather than changes in V cmax. Diurnal variation in g m appeared to be associated more with endogenous than with atmospheric factors.  相似文献   

7.
Most cultivars of Japanese pear (Pyrus pyrifolia Nakai) exhibit gametophytic self-incompatibility controlled by a single S-locus with multiple S-haplotypes. A self-compatible (SC) cultivar, ??Osanijisseiki?? (S 2 S 4 sm ), arising by a bud mutation of ??Nijisseiki?? (S 2 S 4 ), has a stylar-part mutant S 4 sm -haplotype, which lacks the pistil S 4 gene, which is the S 4 -RNase gene. To efficiently breed SC cultivars, we selected ??Nashi Chuukanbohon Nou 1 Gou?? (??NCN1??) harboring homozygous S 4 sm from a self-progeny of Osanijisseiki and crossed it with ??Okusankichi?? (S 5 S 7 ), ??Hakkou?? (S 4 S 5 ), or ??Ri-14?? (S 1 S 2 ). Fruit set (%) was compared after self-pollination of the trees in the three progenies. All trees derived from the three progenies were predicted to be SC, except for the S 4 S 4 sm trees in the progeny of NCN1 × Hakkou. However, S 1 S 4 sm trees in the progeny of NCN1 × Ri-14 proved to be self-incompatible (SI). The pollen from Osanijisseiki was incompatible with ??Doitsu?? (S 1 S 2 ), but that from Nijisseiki was compatible, suggesting a possibility that the S 4 sm pollen was rejected by S 1 -harboring pistils. This possibility was clarified by crossing the pollen from NCN1 (S 4 sm S 4 sm ) to Doitsu, ??Imamuraaki?? (S 1 S 6 ), or ??Hougetsu?? (S 1 S 7 ), all of which proved incompatible. On the other hand, S 4 sm pollen was accepted by pistils harboring the S 2 , S 3 , S 5 , S 6 , S 7 , S 9 , and S k haplotypes. The dual recognition of S 1 and S 4 pistils by S 4 sm pollen can be attributed to a mutation of the pollen S 4 gene(s).  相似文献   

8.
In this study, S-allele diversity of eight wild and two commercial species of the Cerasus subgenus in Iran was investigated using two primer pairs. A high level of S-allele polymorphism was detected among and within the species evaluated. Furthermore, most of wild species showed 2–4 alleles based on S-allele primers and may be considered as tetraploid. Sweet cherry cultivars, Siah-Mashhad, Siah-Shabestar, Takdaneh-Mashhad, Siah-Daneshkadeh and Protiva showed S3S12, S3S12, S3S12, S3S5 and S3S4 combinations, respectively, allele S3 showing the highest frequency. Three Iranian sweet cherry cultivars had the same allelic combination (S3S12) that the same ancestor in genealogy of these cultivars may explain the loss of diversity observed at the S-locus. Wild cherry (mazzard) accessions showed wide range of alleles such as S1, S2, S7, S14 and S20 and unknown alleles, while sour cherries showed S6, S9, S13 and S27 alleles. In conclusion, the conservation of these highly diverse native species of Iranian wild Cerasus germplasm is recommended for future breeding activity.  相似文献   

9.
10.
Karyotypes, sex chromosome systems and meiotic characteristics are reported for ten spider species belonging to the families Gnaphosidae, Philodromidae, Salticidae, Oxyopidae and Sicariidae by using standard Giemsa staining. The male diploid numbers (2n) and sex chromosome systems are as follows: Berinda hakani 2n = 22 (X1X2), Berinda ensigera 2n = 22 (X1X2), Trachyzelotes lyonneti 2n = 22 (X1X2), Trachyzelotes malkini 2n = 22 (X1X2), Zelotes caucasius 2n = 22 (X1X2) (Gnaphosidae); Thanatus pictus 2n = 28 (X1 X2), Tibellus macellus 2n = 24 (X1 X2) (Philodromidae); Neon reticulatus 2n = 21 (X0) (Salticidae); Peucetia virescens 2n = 28 (X1X2) (Oxyopidae) and Loxosceles rufescens 2n = 21 (X1 X2Y) (Sicariidae). All species have monoarmed chromosomes with the exception of L. rufescens that has biarmed (metacentric and submetacentric) chromosomes. The obtained data are the first results for the genera Berinda, Trachyzelotes and Neon. Additionally, with the exception of L. rufescens, all species are being chromosomally analyzed for the first time.  相似文献   

11.
Clearance studies were performed in mice using α2-macroglobulin (α2M), α2M-trypsin comlex and α2M-CH3NH2 complex. All three species were incubated with cis-dichlorodiamine platinum(II) (cis-DDPt) at concentrations between 9.0 μM and 1.67 mM for 4 h and then dialyzed. The clearance rate of native α2M was unchanged following incubation with cis-DDPt. α2M-trypsin and α2M-CH3NH2 cleared rapidly from the ciruculation; however, reaction with cis-DDPt significantly decreased the plasma elimination rate of both complexes. Non-denaturing gel electrophoresis and α2M activity assays demonstrated relative stability following incubations with cis-DDPt which markedly altered clearance. Evidence for cis-DDPt crosslinking of α2M subunits was obtained: however, whether this crosslinking is involved in altered clearance remains undetermined. Iodoacetamide treatment of α2M did not duplicate the effect of cis-DDPton α2M clearance, nor did it inhibit the effect of cis-DDPt on α2M clearance. Plasma elimination of α2M complex was also unaltered by pretreatment of mice with intravenous free cis-DDPt.  相似文献   

12.
《Inorganica chimica acta》1986,121(2):167-174
The reaction of 2,3-tri with CrCl3·6H2O1, dehydrated in boiling DMF, results in the formation of mer-CrCl3(2,3-tri) and anation of hydrolysed solutions of mer-MCl3(2,3,-tri) (M=Co, Cr) with 6 M HCl containing HClO4, forms trans-dichloro- mer-[MCl2(2,3-tri)(OH2)]ClO4·H2O (M=Cr, Co; I, II). trans-Dinitro-mer-[Co(NO2)2(NH3)(2,3-tri)] ClO4 crystallises from the reaction between mer-Co(NO2)3(2,3-tri) and aqueous 7 M ammonia, on addition of NaClO4·H2O, and trans-dichloro-mer-[CoCl2(NH3)(2,3-tri)]ClO4 (III) can be isolated by treatment of the dinitro with 12 M HCl. Reaction of mer-CoCl3(2,3-tri) with C2O42, followed by addition of aqueous NH3 and NaClO4·H2O results in the isolation of racemic mer-[Co(ox)(NH3)(2,3-tri)]ClO4· H2O. This complex was resolved into its enantiomeric forms and treatment of these with SOCl2/MeOH/ HClO4 gave the chiral forms of trans-dichloro-mer- [CoCl2(NH3)(2,3-tri)]ClO4 (R or S at the see-NH center). The rates of loss of the first chloro ligand from these dichloro complexes have been measured spectrophotometrically in 0.1 M HNO3 over a 15 K temperature range to give the following kinetic parameters; (I) kH(298)=7.25 × 10−5 s−1, Ea=78.5 kJ mol−1, δS298#=69 J K−1 mol−1; (II) kH(298)=4.00 × 10−3 s−1, Ea=89.9, δS298#= +87.5; (III) kH(298)=3.09 × 10−4 s−1, Ea=103, δS298#=+27. Treatment of the dichloro cations with Hg2+/HNO3 results in the generation of mer- M(2,3-tri)(OH2)33+ (M=Cr, Co; IV, V) and trans- diaqua-mer-Co(NH3)(2,3-tri)(OH2)23+ (VI). The Co(III) cations isomerise to the fac configuration with (V) Kisom(298) μ=1.0 M)=2.97 × 10−5 s−1, Ea=115, δS298#=+46. (VI) Kisom(298) (μ=1.0 M)=4.13 × 10−5 s−1, Ea=113, δS298#=+52.  相似文献   

13.
Self-incompatibility has been studied extensively at the molecular level in Solanaceae, Rosaceae, and Scrophulariaceae, all of which exhibit gametophytic self-incompatibility. In the present study, we successfully isolated nine S-RNase alleles from cultivars of Chinese cherry by PCR amplification from genomic DNA and stylar cDNA combining with cleaved amplified polymorphic sequence marker. Analysis of amino acid sequences revealed five novel S-alleles, S 2 , S 4 , S 6 , S 8 , and S 9 , with respective accession numbers in the NCBI database of EF541168, EF541173, EF541172, FJ628598, and FJ628599. Results showed that “Dongtang” and “Yinzhu” contained six S-alleles (S 1 , S 3 , S 5 , S 7 , S 8 , and S 9 ); “Taishanganying” contained four S-alleles (S 1 , S 2 , S 4 , and S 6 ); “Daiba”, “Dayingzui”, and “Xiaomizi” contained four S-alleles (S 1 , S 2 , S 5 , and S 8 ); “Laiyangduanzhi”, “Shuangquanchangba”, and “Daqingye” contained three S-alleles (S 1 , S 2 , and S 8 ). It is interesting that different cultivars collected from the same place hold the same S-genotypes. Moreover, pollination tests and pollen tube growth assays showed that nine cultivars were self-compatible. Chinese cherry presented in this article are naturally polyploidy, which is a very useful material for the study of self-compatibility, and much of this information will be valuable for further work on self-(in)compatibility of fruit tree in Rosaceae.  相似文献   

14.
During a large hospital outbreak of OXA-48 producing bacteria, most K. pneumoniae OXA-48 isolates were phenotypically resistant to meropenem or imipenem, whereas most E. coli OXA-48 isolates were phenotypically susceptible to these antibiotics. In the absence of molecular gene-detection E. coli OXA-48 could remain undetected, facilitating cross-transmission and horizontal gene transfer of bla OXA-48. Based on 868 longitudinal molecular microbiological screening results from patients carrying K. pneumoniae OXA-48 (n = 24), E. coli OXA-48 (n = 17), or both (n = 40) and mathematical modelling we determined mean durations of colonisation (278 and 225 days for K. pneumoniae OXA-48 and E. coli OXA-48, respectively), and horizontal gene transfer rates (0.0091/day from K. pneumoniae to E. coli and 0.0015/day vice versa). Based on these findings the maximum effect of horizontal gene transfer of bla OXA-48 originating from E. coli OXA-48 on the basic reproduction number (R 0) is 1.9%, and it is, therefore, unlikely that phenotypically susceptible E. coli OXA-48 will contribute significantly to the spread of bla OXA-48.  相似文献   

15.
Complexes of the types cis- and trans-Pt(amine)2I2 were studied by spectroscopic methods, especially by multinuclear NMR spectroscopy. In 195Pt NMR, the cis diiodo compounds with primary amines were observed between −3342 and −3357 ppm in acetone, while the trans compounds were found between −3336 and −3372 ppm. For the secondary amines, the chemical shifts were observed at lower fields. In 1H NMR, the trans complexes were observed at higher fields than the cis compounds, while in 13C NMR, the reverse was observed. The 2J(195Pt-1H) and 3J(195Pt-1H) coupling constants are larger for the cis compounds (ave. 67 and 45 Hz, respectively) than for the trans isomers (ave. 59 and 38 Hz). In 13C NMR, the values of 2J(195Pt-13C) and 3J(195Pt-13C) were also found to be larger for the cis complexes (ave. 17 and 39 Hz versus 11 and 28 Hz). There seems to be a slight dependence of the pKa values of the protonated amines or the proton affinity in the gas phase with the δ(Pt) chemical shifts. The crystal structures of eight diiodo complexes were determined. These compounds are cis-Pt(CH3NH2)2I2, cis-Pt(n-C4H9NH2)2I2, cis-Pt(Et2NH)2I2, trans-Pt(n-C3H7NH2)2I2, trans-Pt(iso-C3H7NH2)2I2, trans-Pt(n-C4H9NH2)2I2, trans-Pt(t-C4H9NH2)2I2 and trans-Pt(Me2NH)2I2. The Pt-N bond distances located in trans position to the iodo ligands were compared to those located in trans position to the amines. The Pt-N bond in cis-Pt(Et2NH)2I2 are much longer than the others, probably caused by the steric hindrance of the two very bulky ligands located in cis positions.  相似文献   

16.
Combination of (1S,2S)-cyclopentanediylbis(diphenylphosphine) with [Ru(η4-C8H12){η3-(CH2)2CMe}2] afforded the chelate complex [Ru{η3-(CH2)2CMe}2{(1S,2S)-C5H8(PPh2)2}] (1), which gave (OC-6-13)-[RuCl2{(1S,2S)-C5H8(PPh2)2}{(1S,2S)-Ph2PCH(Ph)CH(Me)NH2}] (2) upon reaction with methanolic HCl in acetone, followed by the addition of the β-aminophosphine in DMF. The (P  N)2-chelated complexes (OC-6-13)-[RuCl2{(1S,2S)-Ph2PCH(Ph)CH(Me)NH2}2] (3) and (OC-6-13)-[RuCl2{(1R,2S)-Ph2PCH(Ph)CH(Me)NH2}2] (4) resulted from RuCl3 · 3H2O and the P,N ligands under reducing conditions. The crystal structures of 3 and 4 were determined by single-crystal X-ray diffraction. Following activation by KOBu-t in isopropanol, compounds 24 catalyzed the enantioselective transfer hydrogenation of acetophenone with i-PrOH as the hydrogen source as well as the direct hydrogenation of the ketone by H2 in low to moderate e.e. (up to 67%).  相似文献   

17.
The average electron thermal energies in the emission flux from the electrode into the plasma, ? 1, and from the plasma toward the electrode, ? 2, are determined for the cases of large and small values of the coefficient of kinetic reflection. It is shown that these energies vary within the ranges 0.5k B T c < ? 1 < 2k B T c and 0.5k B T e < ? 2 < 2k B T e , where T c and T e are the temperatures of the cathode and plasma electrons, respectively. The obtained values can be used to formulate the boundary conditions for the hydrodynamic equations at the electrode or a dielectric wall.  相似文献   

18.
With an ecological-evolutionary perspective increasingly applied toward the conservation and management of endangered or exploited species, the genetic estimation of effective population size (Ne) has proliferated. Based on a comprehensive analysis of empirical literature from the past two decades, we asked: (i) how often do studies link Ne to the adult census population size (N)? (ii) To what extent is Ne correctly linked to N? (iii) How readily is uncertainty accounted for in both Ne and N when quantifying Ne/N ratios? and (iv) how frequently and to what degree might errors in the estimation of Ne or N affect inferences of Ne/N ratios? We found that only 20% of available Ne estimates (508 of 2617; 233 studies) explicitly attempted to link Ne and N; of these, only 31% (160 of 508) correctly linked Ne and N. Moreover, only 7% (41 of 508) of Ne/N ratios (correctly linked or not) reported confidence intervals for both Ne and N; for those cases where confidence intervals were reported for Ne only, 31% of Ne/N ratios overlapped with 1, of which more than half also reached below Ne/N = 0.01. Uncertainty in Ne/N ratios thus sometimes spanned at least two orders of magnitude. We conclude that the estimation of Ne/N ratios in natural populations could be significantly improved, discuss several options for doing so, and briefly outline some future research directions.  相似文献   

19.
As a prerequisite to studying the genetics and breeding of chasmogamous and cleistogamous flowers, a preliminary experiment was performed to estimate the extent of cross-pollination in cotton varieties and hybrids. Vicinism estimates varied from 0.53 to 15.36%, i.e., the proportion of cross-pollination was relatively high, leading to a biological contamination. As a result of such contamination, genetic collection lines and varieties lose genetic homogeneity and become heterozygous and genetically heterogeneous. The genetic control of the flower type was studied in the Gossipium hirsutum L. × G. barbadense L. interspecific hybrids, and phenotypic segregation of the 3: 1 and 15: 1 types with monogenic (3: 1) and digenic (15: 1) differences of noncumulative polymerization was observed. The corresponding types of genotypic segregation were 1: 2: 1 (1Cg 1 Cg 1 cg 2 cg 2 : 2Cg 1 cg 1 cg 2 cg 2 : 1cg 1 cg 1 cg 2 cg 2 ) and 1: 2: 2: 4: 1: 2: 1: 2: 1 (1) Cg 1 Cg 1 Cg 2 Cg 2 -1; (2) Cg 1 Cg 1 cg 2 cg 2 -2; (3) Cg 1 cg 1 Cg 2 Cg 2 -2; (4) Cg 1 cg 1 Cg 2 cg 2-4; (5) Cg 1 Cg 1 cg 2 cg 2 -1; (6) Cg 1 cg 1 cg 2 cg 2 -2; (7) cg 1 cg 1 Cg 2 Cg 2-1; (8) cg 1 cg 1 Cg 2 cg 2 -2; (9) cg 1 cg 1 cg 2 cg 2 -1. Genotypes (1)–(8) had chasmogamous flowers, while double-recessive genotype (9) had cleistogamous flowers. Based on this, genotypes with individual phenotypic expression were identified in F2, and their correlation with the most important morphological, biological, and agricultural features was studied. Special attention was paid to the productivity of hybrid plants intended for use in breeding to obtain intensive varieties. The study made it possible to isolate forms, families, genetic collection lines, and varieties with isogenic or nonisogenic determination of these characters and chasmogamous and cleistogamous flowers of G. hirsutum L. and G. barbadense L. prototypes by using original methods to examine the two types of flowers; the methods do not have analogs in cotton breeding worldwide.  相似文献   

20.
The concentration-dependence of the diffusion and sedimentation coefficients (kD and ks, respectively) of a protein can be used to determine the second virial coefficient (B2), a parameter valuable in predicting protein-protein interactions. Accurate measurement of B2 under physiologically and pharmaceutically relevant conditions, however, requires independent measurement of kD and ks via orthogonal techniques. We demonstrate this by utilizing sedimentation velocity (SV) and dynamic light scattering (DLS) to analyze solutions of hen-egg white lysozyme (HEWL) and a monoclonal antibody (mAb1) in different salt solutions. The accuracy of the SV-DLS method was established by comparing measured and literature B2 values for HEWL. In contrast to the assumptions necessary for determining kD and ks via SV alone, kD and ks were of comparable magnitudes, and solution conditions were noted for both HEWL and mAb1 under which 1), kD and ks assumed opposite signs; and 2), kDks. Further, we demonstrate the utility of kD and ks as qualitative predictors of protein aggregation through agitation and accelerated stability studies. Aggregation of mAb1 correlated well with B2, kD, and ks, thus establishing the potential for kD to serve as a high-throughput predictor of protein aggregation.  相似文献   

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