bluuebunny/crossref_metadata_2025_split huggingface dataset:
Growth of laboratory‐reared ship rats (Rattus rattus L.)
Authors: BENTLEY E. W. , TAYLOR EILEEN J. 
Published: March 2008

SUMMARYMean weight‐on‐age curves for eighty‐two male and sixty‐five female Rattus rattus reared in the laboratory show that at birth the males were slightly heavier on the average than the females; for a week or two the females gained weight more quickly, but at 5–6 weeks of age the males became significantly heavier again and remained so. A change in growth rate seemed to occur in both sexes at about 7 days and again at about 6 weeks in the males and at 8–9 weeks in the females. In the females initial weight was significantly correlated with maximum weight: in the males it was significantly negatively correlated with the age at which maximum weight was achieved.In both sexes, at all ages from birth onwards, some rats weighed twice as much as others. This militates against the use in the field of weight as a guide to age. Variability in weight was very largely a consequence of differences between litters.The mean maximum weight attained by seventy‐two males was 215g.; the heaviest weighed 305g. The mean maximum reached by fifty females was 173g. and the heaviest weighed 260g. The mean age of attainment of maximum weight was 504 days for males and 553 days for females: the difference was not significant.The mean age at death of the males that died of 'natural' causes was 779: that of the females was 837 days. This difference was also non‐significant. Longevity was significantly correlated with both maximum weight and the age at which it was attained. Life tables are presented for male and female rats that survived to 35 days and died both from 'natural' causes and from all causes. Factors are given for calculating the corresponding probabilities of survival from birth.The average number of rats per litter was 6·2: the ratio of the two sexes at birth did not differ significantly from unity.No differences in body weight could be distinguished between the two colour forms of Rattus rattus that are commonest in Britain.
The ingestion of nitrogen and solid matter from Vicia faba by Aphis fabae Scop.
Authors: BANKS C. J. , MACAULAY E. D. M. 
Published: March 2008

SUMMARY Aphis fabae were reared on two varieties of field bean (Vicia faba) on which they differ in fecundity, and the total amounts of solids and nitrogen ingested and assimilated during larval life and during the reproductive and early post‐reproductive life were estimated. Larvae ingested 0·7–0·8mg. solids containing 0·02–0·03mg. nitrogen in 7 days of larval life; they ingested and excreted more solids and nitrogen from one variety. Adult virginoparae ingested 4·4–4·9mg. solids containing 0·08–0·09mg. nitrogen during the reproductive life of 3 weeks; they ingested almost equal amounts of solids from each variety and, like the larvae, assimilated about 20%; their dry weights increased slowly during reproductive life and rapidly during early post‐reproductive life. Adults assimilated 70% and larvae 50% of the nitrogen ingested and, although larvae assimilated and excreted significantly more nitrogen on one variety, the adults assimilated more nitrogen on the other variety, on which they produced significantly more larvae. The nitrogen content of the sap of both varieties seems more than adequate for the aphids to grow and reproduce and did not determine fecundity.
The species, aerial density and sexual maturity of Thysanoptera caught in mass flights
Authors: LEWIS T. 
Published: March 2008

SUMMARYThe commonest Thysanoptera in mass flights between ground level and 1000 ft. in south‐east England are females of species dwelling on grasses and cereals. Individuals with immature ovaries probably disperse over the greatest distances. Aerial densities as large as 60,000 thrips per 106 cu. ft. were recorded.
Treatment of soil with chemicals to prevent transmission of tomato blackring and raspberry ringspot viruses by Longidorus elongatus (de Man)
Authors: MURANT A. F. , TAYLOR C. E. 
Published: March 2008

SUMMARYThe use of chemical soil treatments to control the nematode, Longidorus elongatus, which transmits raspberry ringspot and tomato blackring viruses, was studied in a 4‐year field trial.In untreated soil, after an overwinter fallow, the nematodes lost their infectivity, but regained it in the spring from germinating infected weed seeds. In soil treated with D‐D (with or without a surface seal of solubilized xylenols) at 400 lb./acre, 95% of the L. elongatus were killed. This treatment, and that with 20% quintozene at 1200 lb./acre, prevented transmission of virus to Talisman strawberries throughout the 4‐year experiment.In both treated and untreated soils, L. elongatus populations increased about fourfold each year after strawberries were planted but, because of the initial kill, the populations in the D‐D plots at the end of the experiment were approximately only one‐eighth of those in the control plots.After the first year, both D‐D and quintozene treatments led to significant increases in crop, reaching 130% in the third fruiting season.Metham‐sodium and thiram, at the doses used, were only partially effective as nematicides: by the end of the second growing season the numbers of L. elongatus in the plots receiving these treatments equalled those in the untreated soil, and the infectivity had returned almost to its original level.
Studies on plant growth‐regulating substances. XX. The metabolism of γ‐(2,4,5‐trichlorophenoxy)butyric acid in wheat and pea stem tissues
Authors: BALAYANNIS P. G. , SMITH M. S. , WAIN R. L. 
Published: March 2008

SUMMARYGas chromatography has been used to study the capacity of wheat and pea stem tissues and growing seedlings to degrade the side chain of γ‐(2,4,5‐trichlorophenoxy)butyric acid. The substance was converted to its acetic derivative in wheat, presumably undergoing β‐oxidation within the tissues. No evidence for such breakdown was obtained in pea stems. The results are fully consistent with the earlier findings of Wain and Wightman who studied these same systems by other methods.
Factors in testing fungicides against powdery mildews. II. Tests against oat powdery mildew in the greenhouse
Authors: ZARACOVITIS C. 
Published: March 2008

SUMMARYSome factors affecting fungicidal efficiency were studied during greenhouse tests with Erysiphe graminis on oat seedlings. In a comparison of non‐ionic, cationic and anionic surface‐active compounds, for formulating chemicals for testing, 'Ethylan CP' at 0·0025% in demineralized water at 30°C., plus 1–2% of acetone or ethyl alcohol, was found satisfactory and was used throughout later work. Studies of the effect of time of eradicant application on the efficacy of 'dinocap', lauric acid and a captan analogue demonstrated that these chemicals applied 24 hr. after inoculation were significantly less effective than at 48 and 72 hr. Fungitoxicity trials using a homologous series of n‐alkyl fatty acids and related compounds showed that lauric acid applied at 2·5 X 10‐4m as an eradicant 48 hr. after inoculation gave 99% reduction of infection. Of the related compounds, n‐alkylamines with 11–13 carbon atoms equalled the acids in activity, but the amides and fatty alcohols at the same molar concentration were inactive.
Single‐bath hot‐water treatment for the control of loose smut (Ustilago nuda) in cereals
Authors: DOLING D. A. 
Published: March 2008

SUMMARYThe single‐bath hot‐water treatments for the control of loose smut in wheat and barley give satisfactory results over a range of time/temperature combinations. Thus the soaking period recommended for wheat ranges from 1 1/2–2 hr. at 120°F. (49°C.) to 5–6 hr. at 105°F. (41°C): for barley the range is from 1 1/2 hr. at 120 to 5 hr. at 105°F. The general relationship in these treatments may be expressed as t=k logh+c, where t= temperature, h= minimum no. of hours required and k and c are constants.
Some ecological factors influencing the proportion of loose smut (Ustilago nuda (Jens.) Rostr.) in wheat crops
Authors: DOLING D. A. 
Published: March 2008

SUMMARYCappelle–Desprez winter wheat produced different proportions of smutted ears when grown at several centres throughout the country. This variation was not simply related to crop density, though plots which showed poor establishment in 1961/62 gave very low numbers of smutted ears.After grading the seed it was found that the smallest seed size contained a higher proportion of smutted grains.Spaced‐plant studies showed that the earing capacity of healthy and infected seedlings differed. The number of smutted ears per infected plant was less than the number of ears per healthy plant and the proportion of smutted ears decreased as the total number of ears of an infected plant increased.It is concluded that the differences in the proportion of smutted ears at different centres could be the result of competition for establishment between healthy and infected seedlings or be due to the differential tillering capacity of the two kinds of plants.
The epidemiology of Phytophthora infestans. IV. Spraying trials, 1959 to 1963, and the infection of tubers
Authors: HIRST J. M. , STEDMAN O. J. , LACEY J. , HIDE G. A. 
Published: March 2008

SUMMARYThe methods needed to decrease losses from potato blight in the variety Majestic are different from those required for King Edward. Few Majestic tubers become infected and control depends chiefly on prolonging the life of the haulm to ensure the maximum yield of tubers. With King Edward, infected tubers often cause more loss than premature defoliation. Tuber infection often occurs very early in the attacks, when profuse sporulation coincides with sufficient rain to penetrate through soil to the tubers.Spraying with fungicide delayed initial tuber infection of King Edward but did not necessarily decrease the proportion of tubers infected at harvest. The largest yield of sound tubers from fungicide‐sprayed plots in the 1960 epidemic was obtained after killing the haulm when only 5% had been destroyed by blight. Allowing the foliage to survive later than this stage did not increase the yield of sound tubers even in years when blight attacks were late and slow. Protection with fungicide and haulm destruction are complementary treatments, both of which require careful timing to obtain the best result with tuber‐susceptible varieties.
Seasonal fluctuations in spore concentrations of Podosphaera leucotricha (Ell. and Ev.) Salm. in relation to the incidence of leaf infections
Authors: BURCHILL R. T. 
Published: March 2008

SUMMARYIn spore trapping studies in 1963 and 1963, apple mildew (Podosphaera leucotricha (Ell. and Ev.) Salm.) conidia were not detected in the atmosphere until just before the pink bud stage. Spore concentrations reached a maximum in June, thereafter a series of minor peaks occurred until the end of September in 1962 and the end of August in 1963.The June peak of spore release was followed approximately 2 weeks later by a rise in the incidence of new leaf infections.The importance to the perennation of the disease of these high spore concentrations and possible methods of restricting their increase are discussed.
The toxicity of nonyl phenol ethoxylate to the developmental stages of the rainbow trout, Salmo gairdnerii Richardson
Authors: MARCHETTI R. 
Published: March 2008

SUMMARYSuccessive developmental stages of Salmo gairdnerii showed marked differences in their resistance to the action of the non‐ionic surfactant, nonyl phenol ethoxylate. The alevins, immediately after hatching, were highly resistant and survived concentrations of up to 42 p.p.m. for 6 hr. This resistance gradually decreased with the absorption of the yolk sac: when the yolk had been completely absorbed and before the fry had fed the lethal concentration was 2·5 p.p.m.After several days of feeding, resistance slightly increased but showed no further rise after 15 days. A concentration of 5·2 p.p.m. of nonyl phenol ethoxylate for 6 hr. was toxic both to 40‐ and to 210‐day‐old fish.It is considered that these changes in resistance are not correlated with changes in respiratory activity of the fish but with their water metabolism.
Comparative assessment of dosage distributions in cotton resulting from helicopter and ground‐spray treatments
Authors: JOHNSTONE D. R. , MATTHEWS G. A. 
Published: March 2008

SUMMARYThe distribution of carbaryl resulting from helicopter and ground spray applications on Rhodesian‐grown cotton plants at different stages of growth has been measured. Results for dosage distributions on leaves indicate that at all stages of growth the deposit after helicopter spraying was greatest on the top part of the plant, particularly on the upper surface of the leaves. In general considerably more even cover, though again with higher relative deposit on the upper leaf surface, was recorded after the ground spray treatments.
Field experiments with chat‐fruit virus disease of apple
Authors: POSNETTE A. F. , CROPLEY R. 
Published: March 2008

SUMMARYUsing the indicator variety, Lord Lambourne, apple chat‐fruit virus was detected in some plants of the apple rootstock clones M. IV and M. VII but not in clones M. I, M. II, M. III, M. IX, M. XII, M. XVI and Crab C. The virus occurred in three nurserymen's Lord Lambourne scion material but not in that of a fourth.Fruit weights were more reliable than visual observations for diagnosis of chat‐fruit disease, especially in young trees. Natural spread of the disease in these field trials was very slow and insufficient to interfere with interpretation of results.Infection was not fully systemic in apple trees, so that both healthy and infected trees were propagated from affected trees, some buds from which, when used as graft‐inoculum, transmitted the virus to test trees while others did not.Two previously unrecorded effects of chat‐fruit disease were observed: circular spots on the fruit and delayed fruit drop.
The ‘hardening’ effect of lime‐sulphur sprays on maiden apple trees
Authors: LLEWELYN F. W. M. 
Published: March 2008

SUMMARYMaiden Mailing IV apple rootstocks were sprayed with 2% lime‐sulphur on four occasions and all combinations of these occasions both in the presence and absence of weekly sprays of 0·05% didecyldimethylammonium bromide (DDAB). The effect of these spray schedules was measured fortnightly as the ratio of the dry weights of extension growth plus leaves of sprayed to un‐sprayed plants. DDAB had no effect upon the growth of the plants. Maximum damage from the lime‐sulphur sprays occurred during the first fortnight after spraying, the ratio rising again to unity during the next 6 weeks. Early sprays of lime‐sulphur resulted in less damage being done by later sprays, thus confirming quantitatively the reported 'hardening' effect of these sprays.
The effects of an artificial windbreak on the aerial distribution of flying insects
Authors: LEWIS T. 
Published: March 2008

SUMMARYSuction traps were used to measure the aerial density of insects near a low, slatted wooden fence on an otherwise exposed plot. When winds blew approximately at right angles to the fence insects gathered in the air near to it, especially to leeward, where they were from 2 to 27 times as concentrated as elsewhere. The increases in concentration extended farther to leeward for day‐flying insects than for night‐flyers. These accumulations were caused mainly by wind, and turbulence in the incident air stream had a greater influence than wind velocity. The relative density profiles for winged insects, spiders and inert particles measured near the fence had much the same pattern except that, close to the fence, the insects and spiders were more concentrated than the particles; strong day‐flying insects gathered to leeward in greater numbers than weak day‐flyers or night‐flyers.
Glacial Refugia of Ginkgo biloba and Human Impact on Its Genetic Diversity: Evidence from Chloroplast DNA
Authors: Gong Wei , Zeng Zhen , Chen Ye‐Ye , Chen Chuan , Qiu Ying‐Xiong , Fu Cheng‐Xin 
Published: March 2008

Abstract Variations in the trnK region of chloroplast DNA were investigated in the present study using polymerase chain reaction–restriction fragment length polymorphism to detect the genetic structure and to infer the possible glacial refugia of Ginkgo biloba L. in China. In total, 220 individuals from 12 populations in China and three populations outside China were analyzed, representing the largest number of populations studied by molecular markers to date. Nineteen haplotypes were produced and haplotype A was found in all populations. Populations in south‐western China, including WC, JF, PX, and SP, contained 14 of the 19 haplotypes and their genetic diversity ranged from 0.771 4 to 0.867 6. The TM population from China also showed a high genetic diversity (H = 0.848 5). Most of the genetic variation existed within populations and the differentiation among populations was low (GST = 0.2). According to haplotype distribution and the historical record, we suggest that populations of G. biloba have been subjected to extensive human impact, which has compounded our attempt to infer glacial refugia for Ginkgo. Nevertheless, the present results suggest that the center of genetic diversity of Ginkgo is mainly in south‐western China and in situ conservation is needed to protect and preserve the genetic resources.
Relationship between the Virtual Dynamic Thinning Line and the Self‐Thinning Boundary Line in Simulated Plant Populations
Authors: Chen Kang , Kang Hong‐Mei , Bai Juan , Fang Xiang‐Wen , Wang Gang 
Published: March 2008

Abstract The self‐thinning rule defines a straight upper boundary line on log‐log scales for all possible combinations of mean individual biomass and density in plant populations. Recently, the traditional slope of the upper boundary line, −3/2, has been challenged by −4/3 which is deduced from some new mechanical theories, like the metabolic theory. More experimental or field studies should be carried out to identify the more accurate self‐thinning exponent. But it's hard to obtain the accurate self‐thinning exponent by fitting to data points directly because of the intrinsic problem of subjectivity in data selection. The virtual dynamic thinning line is derived from the competition‐density (C‐D) effect as the initial density tends to be positive infinity, avoiding the data selection process. The purpose of this study was to study the relationship between the virtual dynamic thinning line and the upper boundary line in simulated plant stands. Our research showed that the upper boundary line and the virtual dynamic thinning line were both straight lines on log‐log scales. The slopes were almost the same value with only a very little difference of 0.059, and the intercept of the upper boundary line was a little larger than that of the virtual dynamic thinning line. As initial size and spatial distribution patterns became more uniform, the virtual dynamic thinning line was more similar to the upper boundary line. This implies that, given appropriate parameters, the virtual dynamic thinning line may be used as the upper boundary line in simulated plant stands.
Identification of Optimal Hyperspectral Bands for Estimation of Rice Biophysical Parameters
Authors: Wang Fu‐Min , Huang Jing‐Feng , Wang Xiu‐Zhen 
Published: March 2008

Abstract The present study aims to identify the narrow spectral bands that are most suitable for characterizing rice biophysical parameters. The data used for this study come from ground‐level hyperspectral reflectance measurements for five rice species at three levels of nitrogen fertilization during the growing period. Reflectance was measured in discrete narrow bands between 350 and 2 500 nm. Observed rice biophysical parameters included leaf area index (LAI), wet biomass and dry biomass. The stepwise regression method was applied to identify the optimal bands for rice biophysical parameter estimation. This research indicated that combinations of four narrow bands in stepwise regression models explained 69% to 83% variability for LAI, 56% to 73% for aboveground wet biomass and 70% to 83% for leaf wet biomass. An overwhelming proportion of rice information was in a particular portion of near infrared (NIR) (1 100–1 150 nm), red‐edge (700–750 nm), and a longer portion of green (550–600 nm). These were followed by the moisture‐sensitive NIR (950–1 000 nm), the intermediate portion of shortwave infrared (SWIR) (1 650–1 700 nm), and another portion of NIR (1 000–1 050 nm).
Microsatellite DNA Variation of the Gametophyte Clones Isolated from Introduced Laminaria japonica (Phaeophyta) and L. longissima of China and Varieties Derived from them
Authors: Li Bing‐Jun , Shi Yuan‐Yuan , Yang Guan‐Pin , Che Shi , Xiao‐Jie Li , Yi‐Zhou Cong 
Published: March 2008

Abstract The variation of 90 Laminaria gametophyte clones representing the introduced Laminaria japonica (Group 1) and Laminaria longissima (Group 2), the varieties of L. japonica (Group 3) and the varieties derived from interspecific hybrids (Group 4) was determined with 18 microsatellite markers. The allelic diversity and Nei's gene diversity of Group 1 were significantly higher than those of Group 2 (2.9 vs. 1.8 and 0.414 vs. 0.161, respectively), demonstrating that the variation of the introduced L. japonica is richer than that of L. longissima. Both allelic diversity and Nei's gene diversity of Group 3 were lower than those of Group 1, indicating that only a portion of variation of L. japonica was incorporated into the varieties of L. japonica. Significant genetic differentiation was detected between four groups and between female (Population 1) and male (Population 2) gametophyte clones in each group. The variation among groups accounted for 39.95%, while that among populations accounted for 21.65% of the total. The genetic distance between Group 1 and Group 4 was obviously longer than that between Group 2 and Group 4 (0.686 vs. 0.291), indicating that maternal gametophyte clone contributed more variation to the hybrids than the paternal gametophyte clone did.
Establishment of a Multi‐color Genomic in situ Hybridization Technique to Simultaneously Discriminate the Three Interspecific Hybrid Genomes in Gossypium
Authors: Guan Bing , Wang Kai , Zhou Bao‐Liang , Guo Wang‐Zhen , Zhang Tian‐Zhen 
Published: March 2008

Abstract To identify alien chromosomes in recipient progenies and to analyze genome components in polyploidy, a genomic in situ hybridization (GISH) technique that is suitable for cotton was developed using increased stringency conditions. The increased stringency conditions were a combination of the four factors in the following optimized state: 100:1 ratio of blocking DNA to probe, 60% formamide wash solution, 43 °C temperature wash and a 13 min wash. Under these specific conditions using gDNA from Gossypium sturtianum (C1C1) as a probe, strong hybridization signals were only observed on chromosomes from the C1 genome in somatic cells of the hybrid F1 (G. hirsutum × G. sturtianum) (AtDtC1). Therefore, GISH was able to discriminate parental chromosomes in the hybrid. Further, we developed a multi‐color GISH to simultaneously discriminate the three genomes of the above hybrid. The results repeatedly displayed the three genomes, At, Dt, and C1, and each set of chromosomes with a unique color, making them easy to identify. The power of the multi‐color GISH was proven by analysis of the hexaploid hybrid F1 (G. hirsutum × G. australe) (AtAtDtDtG2G2). We believe that the powerful multi‐color GISH technique could be applied extensively to analyze the genome component in polyploidy and to identify alien chromosomes in the recipient progenies.