Ninth Generation Research Articles

Revealing inner structure of the polycarbosilane dendrimers from small-angle neutron scattering data

Polycarbosilane dendrimers of the ninth generation are studied experimentally with small-angle neutron scattering (SANS) method. It is shown that monodispersity, that is, consistency of shape and form between different molecules, is one of the main features of the polycarbosilane dendrimers of the ninth generation. The samples are studied by SANS facility YuMO, Dubna, Russia [1]. The obtained experimental data are analyzed by means of contrast variation method.

Estimation of genetic change in the GIFT strain of Nile tilapia (Oreochromis niloticus) by comparing contemporary progeny produced by males born in 1991 or in 2003

Genetic change in the Genetically Improved Farmed Tilapia (GIFT) Nile tilapia (Oreochromis niloticus) was estimated by comparing the performance of the progeny produced from cryopreserved spermatozoa from the base population with that produced by freshly collected spermatozoa from the ninth generation. The comparison involved artificial fertilization of 13 males from each generation (base and ninth) with a random sample of 18 female brood stock. The progeny produced went through a 120 day grow-out period, after which live weight, standard length, body depth and survival were recorded. The estimated total genetic change in live weight was 64% over nine generations, or 7.1% generation. The genetic change was lower than the estimate reported by Eknath et al. [Eknath, A.E., Dey, M.M., Rye, M., Gjerde, B., Abella, T.A., Sevilleja, R., Tayamen, M.M., Reyes, R.A., Bentsen, H.B., 1998. Selective breeding of Nile tilapia for Asia. 6th World Congress on Genetics Applied to Livestock Production (vol. 27). University of New England, Armidale, Australia, pp 89–96.], but in the present experiment the time span included generations in which there was no selection. We conclude that GIFT is a superior Nile tilapia strain, from which farmers can benefit due to its fast growth rate. The improvement in the latter trait was achieved without any deterioration in survival rate, which has remained high.

Thermodynamic properties of carbosilane dendrimers of the seventh and ninth generations with terminal butyl groups in the temperature range from T → 0 to 600 K

Temperature dependences of the heat capacity of carbosilane dendrimers with butyl terminal groups of the seventh and ninth generations were determined in the temperature range from 6 to 600 K by precision adiabatic vacuum calorimetry and differential scanning (dynamic) calorimetry. The physical transitions were revealed and their thermodynamic characteristics were analyzed. The experimental data obtained were used to calculate the standard thermodynamic functions C p (T), H°(T) − H°(0), S°(T), and G°(T) − H°(0) for the temperature range from T → 0 to 600 K. The thermodynamic function-molar weight isotherms for the dendrimers of the third–ninth generations with terminal butyl groups in the glassy and highly elastic state are linear.

Parental Curse as Invisible Violence: Тhe Discourse of Anti-Maternity in the Traditional Culture of the XIX Century

Curse is an appellative genre, a clichéd verbal proverb that is uttered in belief, that with the assistance of supernatural forces, God or demon, through the magical properties of words, evil will come upon an individual. It is ex­amined through the context of the ideal motherhood discourse in the tradition culture of the XIX and the first half of the XX century, in view that it was perceived to be an idiosyncrasy of female demeanor. Maternity as a cultural construct in the traditional culture of Serbia is based upon the ideal mother­hood discourses as a gift from god, as an innate role for women, an inherent instinct for caring towards others, as an unconditional motherly love. In prac­tice, normative regulations and the concrete actions of a mother are not in complete concurrence, mothers love is not an objective fact, it can be present or not, vary in intensity, it can be selective, but it will depend on the personal history and cultural construct. Through such a focal point, motherly curse is perceived as a form of behavior that can be signified as anti-maternity. In the conceptualization of a parental curse, from one viewpoint, the manner of usual behavior of women that has no real implications on the life of the child is legitimized, and on the other hand, it is believed that a mothers curse has the most potent magical effect and is delivered up to the ninth generation. Parental curse and the ritual of “cursing” do not include a black magic con­notation, and were considered a legitimate social mechanism through which evil was countered with evil i.e. the transgressor was being punished in cases where there existed no formal mechanism of punishment. Through such ac­tions, the community, or family are re-imposing order in the social relations, synchronously sending a message that reaffirms the correct matrix of behavior and moral values of the community.

John Rashleigh Belcher

Brought up in Liverpool in his father's practice, John Belcher was the ninth generation doctor (father to son) in the family. He was educated at Epsom College and thence St...

Association of single nucleotide polymorphism of chicken uncoupling protein gene with muscle and fatness traits

Uncoupling proteins (UCPs) are in the mitochondrial inner membrane and belong to the transporter family. The biological function of UCPs is regulating discharge of proton gradient generated by the respiratory chain. As a result, the production of ATP is diminished, and dissipative heat is yielded. The present study was designed to investigate the association of UCP gene with chicken growth and body composition traits. The ninth generation of the broiler lines divergently selected for abdominal fat was used as a research population. Primers for UCP gene were designed from chicken genomic sequence. A single-nucleotide polymorphism, in the exon3 (T1316C) of UCP gene was detected by the polymerase chain reaction and restriction fragment polymorphism (PCR-RFLP) method. The UCP polymorphism was associated with muscle and fatness traits, such as pectoralis minor weight and abdominal fat weight. The results indicated that UCP gene could be a candidate locus or linked to a major gene which affects muscle and fatness traits in chicken.

Spherical sector model for describing the experimental small-angle neutron scattering data for dendrimers

A new model for interpreting the results of small-angle neutron scattering from dendrimer solutions is proposed. The mathematical description is given and the theoretical small-angle scattering curves for spherical sectors with different parameters are presented. It is shown that the model proposed is in good agreement with the experimental results. Comparison of the experimental small-angle neutron scattering curves for polyallylcarbosilane dendrimers of the ninth generation with model scattering curves suggests that the inner dendrimer sphere is permeable to a solvent whose density is lower than the density of the solvent beyond the dendrimer by a factor of at least 2.

POTENTIAL TO DEVELOP TOLERANCE TO DELTAENDOTOXINS OF Bacillus thuringiensis subsp. Kurstaki IN Plutella xylostella (Lepidoptera: Plutellidae)

This study demonstrates the potential of Plutella xylostella L. to develop tolerance to entomotoxins from Bacillus thuringiensis Subs. kurstaki (Btk.) One susceptible population and one subjected to selection pressure were studied. The first was reared for eight generations without insecticide treatment; for the ninth generation a medium lethal concentration was estimated at 65. Selection of the second population began with Btk treatment. Four continuous generations of the resistant population were exposed to the LC65 concentration estimated for the susceptible population of P. xylostella. The entomotoxin used in the experiment was a 6.4 % formula of Btk (Javelin® WG, Novartis México). In the bioassays, 90 mm diameter discs of cabbage (Brassica oleracea L.) leaves were cut, submerged for 10 seconds in different concentrations of entomotoxins, and placed in Petri dishes where they were infested with third instar larvae, ten larvae per concentration with three replications. The percentage of mortality was quantified 48 hours later. Data analysis was performed using the Probit model. With linear regression in the PcProbit software LC50, LC65, and LC95 were estimated, and relative resistance was calculated. The results indicate that the percentage of mortality of P. xylostella decreases more than 50 % after being subjected to selection pressure and the tolerance factor obtained was approximately 14 times greater.

Genetic and functional evaluation of the level of inbreeding of the Westran pig: a herd with potential for use in xenotransplantation

The Westran pig has been purposely inbred for use in xenotransplantation. The herd originated in the wild from a limited gene pool and has been inbred by repeated full-sib matings for nine generations. The aim of this study was to evaluate the level of inbreeding by functional assays, such as bi-directional MLR and reciprocal skin grafts between herd members, and by genetic analysis using highly polymorphic genetic markers to calculate the level of inbreeding. The MLR between herd members were non-reactive whereas there was a prompt response to third party pig lymphocytes, indicative of a normal immune responsiveness in Westran pigs but isogenicity of the major histocompatibility complex. Skin grafts between male siblings or female sibling skin grafts on male recipients showed prolonged survival but with few exceptions did not survive beyond 100 days suggesting that by the fifth generation the Westran herd was still mismatched at minor histocompatibility antigens. This level of functional inbreeding was confirmed by microsatellite analysis of highly polymorphic markers, which showed that 52 of 53 chromosomally dispersed markers were fixed by the ninth generation. This level of fixation was consistent with 19 to 20 generations of full-sibling inbreeding. The calculated inbreeding coefficient at generation 10 was 0.98159. This analysis confirms that the Westran pig is highly inbred and we propose that analysis of chromosomally dispersed highly polymorphic markers is an accurate and reproducible method for assessing the level of inbreeding of a pig herd.

Restriction fragment length polymorphism of adhesin genehpaA from differentHelicobacter pyloristrains of Chongqing, China

To assess the variability of adhesin gene hpaA between different Helicobacter pylori (H pylori) strains with PCR-restriction fragment length polymorphism (RFLP). Twelve different H pylori strains were chosen to amplify the 710-bp segments of gene hpaA. These strains were NCTC11637, SS1; Chongqing clinical isolates CCS9801, CCS9802, CCS9803, CCS9806, CCS9809, CCS9810, CCS9813, which were gained from patients of gastritis; Mongolia gerbil adapted H pylori strains (abbreviation MG), which were gained from the following steps: gastric mucosal specimens of Mongolia gerbils infected by clinical isolate CCS9803 were cultured and detected, the positive H pylori strains were named as the first generation of Mongolia gerbil adapted H pylori strains (abbreviation MG1) and then were subcultured with healthy Mongolia gerbil to generate MG2, in turn to gain the ninth generation (abbreviation MG9). All hpaA segments, obtained from 12 different H pylori strains, were digested by HhaI and HaeIII individually and analyzed by agarose gel electrophoresis. In all 12 strains, the 710-bp PCR products were successfully amplified and products were cloned to pMD18-T vector respectively, then the recombinant plasmids were digested simultaneously with NcoI and XhoI to recover the small fragments. The objective fragments from 12 different H pylori strains digested with Hae III could be seen as 4 types of bands and 5 types with Hha I. According to the hpaA RFLP patterns, the 12 H pylori strains could be divided into 5 groups: group I, NCTC11637 and SS1; group II, CCS9809, which RFLP type digested with HaeIII was the same as strains of group I, but HhaI RFLP showed difference compared with the other groups; group III, CCS9810; group IV, CCS9803; group V: CCS9801, CCS9802, CCS9806, CCS9813, MG1, MG3 and MG9. The sequence data of 12 hpaA segments were analyzed by DNAsis software and it was observed that: (1) The homologies of base pair and amino acid sequence between strains NCTC11637, SS1, CCS9809 were 99.6% and 98.9%, respectively; (2) The homology of base pair and amino acid sequence between CCS9803 and CCS9810 was 97.7% and 99.1%; (3) That of the rest strains, CCS9801, CCS9802, CCS9806, CCS9813, MG1, MG3, MG9 reached 99.4% and 98.4%; (4) The base pair homologies between all hpaA fragments of different sources were higher than 94.6%, therefore the correspondence of deduced amino acid sequence was higher than 96.8% between each other. The gene hpaA from different H pylori strains revealed variation, and this might provide an effective method for molecular epidemiological survey of H pylori.

Ninth generation international geomagnetic reference field released

The coefficients for the new 9th Generation International Geomagnetic Reference Field (IGRF) were finalized at the XXIII General Assembly of the International Union of Geophysics and Geodesy (IUGG), held in Sapporo, Japan, in July 2003. The IGRF is widely used as a mathematical representation for the Earth's magnetic field in studies of the Earth's deep interior, crust, and ionosphere and magnetosphere. It is the product of a collaborative effort between magnetic field modelers and the institutes involved in collecting and disseminating magnetic field data from observatories and surveys around the world and from satellites.

Construction of giant dendrimers using a tripodal building block.

Giant pentane-soluble organo-silicon dendrimers have been synthesized using a triallylphenol brick according to a new divergent construction that uses a hydrosilylation-nucleophilic substitution sequence up to the ninth generation (G(9)). All the reactions were monitored by (1)H, (13)C, and (29)Si NMR until G(9), indicating that they were clean at the NMR accuracy until this last generation. MALDI TOF mass spectra were recorded for G(1) to G(4) and show the nature and amounts of defects that are intrinsic to the divergent construction. This technique and SEC (recorded up to G(5)) confirm the monodispersity (1.00 to 1.02) from G(1) to G(5). HRTEM and AFM images recorded for the high generations disclose the expected smooth dendrimer size progression and the globular shape. At G(9), the theoretical number of termini (TNT) is 177 407 branches (abbreviation: G(9)-177 047). It is estimated that more than 10(5) terminal branches are actually present in the G(9) dendrimer, far beyond the De Gennes "dense-packing" limit (6000 branches), and it is believed that the branch termini turn inside the dendrimer toward the core. This is corroborated by lower reaction rates and yields for the highest generation numbers presumably due to intradendritic reactions. It is probable that the dendritic construction is limited by the density of branches inside the dendrimer, i.e., far beyond the dense-packing limit.

An interval timer controls the production of sexual morphs in Myzus persicae (Homoptera: Aphididae)

Abstract The interval timer mechanism was examined in two clones of Myzus persicae (Sulzer) originating from peach in Naousa, North Greece. Overwintering eggs were collected in April 1997 and after egg hatch the morphs of progeny were recorded at LD 10 : 14 h and 17 °C until the appearance of sexuals. In one clone, observations were continued until the 21st generation after egg hatch. In addition, the production of sexual morphs was examined in two other clones originating from Lehonia, Central Greece, when apterae (wingless females) were transferred from long to short days and 17 °C in the second and eighth generation of parthenogenetic rearing after their collection from peach trees. In clones from Naousa, the first gynoparae appear and comprise 10% of alate (winged) females in the second half of the third generation after egg hatch. The percentage of gynoparae increased in each consecutive generation, reaching 100% in fifth and seventh generations in clones Nb and Na, respectively. First males appeared later than gynoparae, in fifth and sixth generation in clones Nb and Na, respectively. In clone Nb, the number of males, after their appearance in fifth generation, was relatively constant from the sixth to the ninth generation (10.8–12.3). Then a significant increase was observed in the 10th generation, thereafter remaining relatively constant until the 21st generation (18.1–19.8). A similar trend in the number of males produced was observed in clones deriving from Lehonia.

DETECTION AND VERIFICATION OF QUANTITATIVE TRAIT LOCI AFFECTING TOLERANCE TO LOW PHOSPHORUS IN RICE

Phosphorus (P)-deficiency in rice (Oryza sativa L.) may cause yields reductions. This research was conducted to map quantitative trait loci (QTL) for tolerance to low-P stress in a double-haploid (DH) line, and to verify these loci in another SSD9 population, which is the ninth generation of single-seed-distribution population derived from the same parents. Two populations were cultured solution at different period. By using the linkage map, QTLs for traits associated with tolerance to low-P stress were located. Results indicated that for DH population, one restricted fragment length polymorphism (RFLP) marker located on chromosome 6 was closely associated with relative root dry weight, relative shoot dry weight, and relative total dry weight. Two QTLs affected relative P uptake content. One micro-effect QTL was found to be associated with relative P utilization efficiency. For relative amounts of root exuded acid phosphatase, relative P allocation between shoot and root, relative plant P concentration, and relative shoot P concentration, one micro-effect QTL was detected for each one. Quantitative trait loci for 3 traits were detected for both DH and SSD9 populations, but the loci for each located trait were inconsistent between two populations; the reason for inconsistency in QTLs was analyzed. The main reason could be the difference in solution environment.

Phosphorus-Containing Dendrimers with Ferrocenyl Units at the Core, within the Branches, and on the Periphery

The synthesis of new ferrocene derivatives bearing phenoxy and/or formyl groups allows one to obtain phosphorus-containing dendrimers with ferrocene units at the core, within the branches, and at the periphery. Dendrimers with a ferrocene at the core were built from 1,1‘-ferrocenedicarboxaldehyde up to the fourth generation. A marked dendritic effect is observed for this family of compounds; indeed, the ferrocenyl core is insulated from the outside in the largest dendrimers (32 or 64 CHO end groups), and the molecule is almost electrochemically inactive. The first dendrimers having three consecutive ferrocene layers within the branches are also described; inner layers are oxidized at the same potential, but the outer layer needs a higher potential to be oxidized, owing to the presence of electron-withdrawing formyl groups. Dendrimers bearing ferrocenyl groups at the periphery are synthesized up to the ninth generation. These compounds are the largest redox active dendrimers ever synthesized; all these fer...

Engineering blood meal-activated systemic immunity in the yellow fever mosquito, Aedes aegypti.

Progress in molecular genetics makes possible the development of alternative disease control strategies that target the competence of mosquitoes to transmit pathogens. We tested the regulatory region of the vitellogenin (Vg) gene of Aedes aegypti for its ability to express potential antipathogen factors in transgenic mosquitoes. Hermes-mediated transformation was used to integrate a 2.1-kb Vg-promoter fragment driving the expression of the Defensin A (DefA) coding region, one of the major insect immune factors. PCR amplification of genomic DNA and Southern blot analyses, carried out through the ninth generation, showed that the Vg-DefA transgene insertion was stable. The Vg-DefA transgene was strongly activated in the fat body by a blood meal. The mRNA levels reached a maximum at 24-h postblood meal, corresponding to the peak expression time of the endogenous Vg gene. High levels of transgenic defensin were accumulated in the hemolymph of bloodfed female mosquitoes, persisting for 20-22 days after a single blood feeding. Purified transgenic defensin showed antibacterial activity comparable to that of defensin isolated from bacterially challenged control mosquitoes. Thus, we have been able to engineer the genetically stable transgenic mosquito with an element of systemic immunity, which is activated through the blood meal-triggered cascade rather than by infection. This work represents a significant step toward the development of molecular genetic approaches to the control of vector competence in pathogen transmission.

Quantitative Genetic Variation in Bicyclus Anynana Metapopulations

Parent-offspring regression was used to estimate heritabilities (h2) of eight wing pattern characters plus five principal components of the butterfly Bicyclus anynana. The experiment consisted of six metapopulations with four subpopulations each with an effective subpopulation size Ne = 6 or 12, and additionally, one larger (Ne = 24) panmictic control population. Although the differences in treatments resulted in substantially different inbreeding coefficients at the ninth generation, there were no significantly differences in estimates of h2 among populations. The h2 estimates were moderately high (overall mean h2 = 0.43), even for the smallest most inbred metapopulation (mean h2males = 0.51, mean h2females = 0.35). We discuss why no significant reduction in h2 was detected in this analysis, while approximately similar sample sizes in molecular and fitness analyses were sufficient to detect severe inbreeding effects.

Measurement of genetic variation within and between Japanese quail lines using DNA fingerprinting

The objective of the present experiment was to study genetic variation within and among well-defined Japanese quail lines by DNA fingerprinting. The Japanese quail lines included a randombred control line (R1) and lines developed from R1 by divergent selection over 30 generations for 4-wk BW (HW, LW) and total plasma phosphorus (TPP) (HP, LP), a measure of yolk precursor in the blood. In addition, two sublines (HW-HP, HW-LP) of HW, developed in the ninth generation, were included in the analysis. Males of the sublines were selected for increased 4-wk BW whereas females were selected for increased (HW-HP) or decreased (HW-LP) TPP. Sixteen individual DNA samples per line were digested with HaeIII restriction enzyme and hybridized with Jeffreys' 33.6 probe. The DNA fingerprints were analyzed with computer programs designed to measure band sharing (BS). Within lines, BS ranged from 0.384 to 0.525. The BS within the R1 line was less than that of all selected lines, except for the HP and LP lines, indicating that, in general, selection had increased genetic homogeneity within the selected lines. Between lines, BS was less than within lines and the R1 line had the highest average level of BS (0.278) with the other lines. The BS between lines for the selected lines ranged from 0.230 to 0.308 with an average of 0.265. In the comparison of the R1 line with the selected lines, it appeared that selection for increased TPP or decreased BW may have influenced BS levels. The relationships of the HW line with its sublines (HW-HP and HW-LP) were not accurately predicted by the DNA fingerprinting technique used. All lines were separated, as indicated by the genetic distance between lines.

Population characteristics and tungro transmission by Nephotettix virescens (Hemiptera: Cicadellidae) on selected resistant rice cultivars

AbstractRice green leafhopper Nephotettix virescens (Distant) populations were collected in 1985 from fields planted with a leafhopper resistant rice, Oryza sativa cultivar IR64 in South Cotabato, Philippines. The populations were reared on IR64 for eight generations and tested on six cultivars, including susceptible TN1, moderately resistant IR26 and IR36, and resistant IR54, IR62, and IR64. Leafhoppers excreted larger amounts of basic honeydew, efficiently transmitted two tungro associated viruses, and showed greater population increase and lower nymphal mortality on all cultivars except IR62 than a greenhouse population reared on TN1. Nephotettix virescens were transferred and maintained on TN1, IR26, IR36, IR64, or a mixture of the four cultivars plus IR54 and IR56 in equal proportion. When the TN1-maintained colony was tested at the third generation, its feeding behaviour and tungro transmission rates on test cultivars were similar to those of the original population but amounts of basic honeydew excretion and the transmission rate on the resistant test cultivars were greatly reduced at the seventh or later generations. When the IR26-maintained colony was tested at the sixth, ninth, or 13th generation, it exhibited lower amounts of basic honeydew excretion on the resistant test cultivars but exhibited similar transmission efficiencies on other test cultivars. When the colonies maintained on IR36, IR64, or the cultivar mixture were tested similarly, their population characteristics and virus transmission efficiency were similar to the original population. These results indicate that N. virescens retain their ‘virulence’ to resistant cultivars when maintained on resistant cultivars, but quickly lose their ‘virulence’ when maintained on a susceptible cultivar. Colonies continuously reared on IR26, IR36 or IR64 showed ‘cross-virulence’ to many cultivars possessing a variety of genes for N. virescens resistance but often differed in feeding behaviour, virus transmission efficiency, and nymphal mortality on cultivars with the same genes for leafhopper resistance.

Divergent Selection for Body Weight and Yolk Precursor in Coturnix coturnix japonica.: 10. Response to Selection Over Thirty Generations

Japanese quail lines were divergently selected for 30 generations for 4-wk BW (HW, LW) or plasma yolk precursor (HP, LP) as measured by total plasma phosphorus (TPP) at the beginning of lay. The HW, LW, HP, and LP lines were initiated from a randombred control line (R1). In the ninth generation of selection in the HW line, sublines were developed by continuing to select males for increased 4-wk BW whereas females were selected for increased (HW-HP line) or decreased (HW-LP) TPP. Individual selection was used in the HW, LW, HW-HP, and HW-LP lines. In the HP and LP lines, females were individually selected whereas males were selected on their full-sisters’ performance.Realized heritabilities (h2), based on the linear regression of selection responses (corrected for environmental changes) on accumulated selection differentials (weighted for the number of offspring produced) over generations, declined with selection in the HW, LW, HP, and LP lines. The h2 of 4-wk BW in the HW line was 0.42 during the first 10 generations of selection and then declined to 0.30 during the next 20 generations of selection. In the LW line, realized h2 of 4-wk BW was 0.40, 0.16, and −0.12 in Generations 1 through 10, 11 through 20, and 21 through 30, respectively. The respective h2 for TPP in the HP line were 0.29, 0.17, and 0.14. The h2 of TPP in the LP line was 0.35 during the first 10 generations and essentially zero during the next 20 generations.Four-week BW and TPP were negatively associated in the HW, HP, and LP lines. There was no significant relationship between these two traits in the LW line.