bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemical‐based Species Classification of Rhubarb Using Simultaneous Determination of Five Bioactive Substances by HPLC and LDA Analysis
Authors: VanMen Chu , Jang Yu Seon , Zhu Hong Mei , Lee Jae Hyun , Trung Trinh Nam , Ngoc Tran Minh , Kim Young Ho , Kang Jong Seong 
Published: October 2011

ABSTRACTIntoductionRhubarb is a traditional Chinese medicine derived from the rhizome of three species: Rheum tanguticum, Rheum palmatum and Rheum officinale. There are several species that are often misidentified as rhubarb. Taxonomical identification of these various species can be challenging. We have developed an HPLC‐based species classification to identify rhubarb.ObjectiveThe objective of this study was to develop a simple HPLC method for the simultaneous determination of bioactive compounds and identification of medicinal rhubarb rhizome and non‐medicinal species.MethodologyQuantitative analysis was performed on a C18‐column using 0.05 m aqueous phosphoric acid and acetonitrile as the mobile phase under gradient conditions with ultraviolet detection at 280 nm. The method was validated with respect to linearity, accuracy, precision, and recovery. Statistical analysis was used to classify different groups of species.ResultsAll calibration curves showed good linearity (r ≥ 0.9995). The method showed good repeatability with intra‐ and inter‐day standard deviations of less than 1.13% and 1.32%, respectively. The accuracy and recovery of all marker compounds were in the ranges of 98.0 to 102.6% and 99.21 to 102.04%, respectively. Seventeen peaks were selected, and 39 known and 57 unknown samples were classified into five species based on linear discriminant analysis with an accuracy of 100%.ConclusionA chemical‐based species classification method of rhubarb using simultaneous determination of bioactive compounds by HPLC was developed with 39 known samples of five different species and successfully applied to identify 57 unknown samples collected from Korea and China. Copyright © 2011 John Wiley & Sons, Ltd.
Solar home system electrification in dispersed rural areas: a 10‐year experience in Jujuy, Argentina
Authors: Díaz P. , Arias C. A. , Gomez‐Gonzalez M. , Sandoval D. , Lobato R. 
Published: October 2011

ABSTRACTThis paper presents a technical approach to the electrification of dispersed rural areas with the so‐called Solar Home Systems. Lessons learned from the past show not only problems and mistakes but also interesting positive points. The electrification of remote areas, with low‐density population and low energy consumption is still a problem to solve. Sustainability is a main issue addressed in all rural electrification assessment actions, together with financing of programs and systems. This work tries to advance in the knowledge on reliability and maintenance, planning and execution, in a dispersed rural electrification market. It is based on the 10‐year field experience in the province of Jujuy, Argentina. In the most dispersed areas of the province, there are about 3000 households plus a minor number of schools, churches, health posts, and community premises electrified with small individual photovoltaic systems from a decade ago. Most remarkable outcomes from a long‐term operation and monitoring action are summarized and analyzed in the following pages. Copyright © 2011 John Wiley & Sons, Ltd.
GISAXS and AFM study of self‐assembled Fe2O3 nanoparticles and Si nanodots
Authors: Ulyanenkov A. , Chrost J. , Siffalovic P. , Chitu L. , Majkova E. , Erlacher K. , Guerault H. , Maier G. , Cornejo M. , Ziberi B. , Frost F. 
Published: October 2011

AbstractThe self‐assembled iron oxide nanoparticles synthesized by a high‐temperature solution phase reaction and the silicon dots produced by an ion bombardment have been investigated by using atomic force microscopy (AFM) and grazing‐incidence small‐angle scattering (GISAXS) technique. Both methods delivered the consistent results on the estimate for the particle size and shape and primary knowledge on the ordering of the objects. A distorted‐wave Born approximation approach has been used for X‐ray data fitting. In the case of the silicon dots, the dense long‐range particle distribution over the whole sample surface is found, where as FeO nanoparticles exhibit the short‐range correlations. Both results are consistent with the local AFM investigations.
Binding energies of bound polaron in a wurtzite nitride nanowire: Contributions of IO and QC phonon modes
Authors: Zhang Li 
Published: October 2011

AbstractBy employing the two‐parameter variational approach, the binding energies of bound polarons in a quasi‐one‐dimensional wurtzite nanowire (NW) are investigated. Two types of polar optical phonon modes, i.e., the interface optical (IO) and quasi‐confined (QC) phonon modes of wurtzite NWs are taken in account. The results reveal that the phonon contribution to binding energy of bound polaron in GaN NWs reaches ∼370 meV. The quite large contribution of phonon modes to the total binding energy is mainly ascribed to the very strong electron–phonon coupling constant in GaN materials. Moreover, the IO modes plays more important role to the binding energies of bound polaron as the NW radius is small, while the QC modes dominates as the NW radius is relatively large. The calculated results of impurity binding energy are quite consistent with the recent experimental measurement. The numerical results also show that the two‐parameter variational approach is necessary and suitable for the description of impurity states in wurtzite GaN NW structures.
Synthesis of high‐aspect‐ratio, top‐open and ultraflat‐surface TiO2 nanotubes through double‐layered configuration
Authors: Lin Jia , Chen Xianfeng 
Published: October 2011

AbstractIn this Letter, a novel modified anodization was utilized to synthesize high‐aspect‐ratio, top‐open and ultraflat‐surface TiO2 nanotubes. The interruption of voltage during anodization leads to the formation of a double‐layered structure. Due to the weak mechanical connection between the upper and the underlying layer, the two parts can be easily detached. Compared with the conventional ultrasonication method to remove the clusters of nanotubes where rough surfaces resulted, this efficient and reliable strategy may facilitate further applications of TiO2 nanotubes in diverse conditions.magnified image(© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Eddies and interface deformations induced by optical streaming
Authors: Chraibi H. , Wunenburger R. , Lasseux D. , Petit J. , Delville J.-P. 
Published: October 2011

AbstractWe study flows and interface deformations produced by the scattering of a laser beam propagating through non-absorbing turbid fluids. Light scattering produces a force density resulting from the transfer of linear momentum from the laser to the scatterers. The flow induced in the direction of the beam propagation, called ‘optical streaming’, is also able to deform the interface separating the two liquid phases and to produce wide humps. The viscous flow taking place in these two liquid layers is solved analytically, in one of the two liquid layers with a stream function formulation, as well as numerically in both fluids using a boundary integral element method. Quantitative comparisons are shown between the numerical and analytical flow patterns. Moreover, we present predictive simulations regarding the effects of the geometry, of the scattering strength and of the viscosities, on both the flow pattern and the deformation of the interface. Finally, theoretical arguments are put forth to explain the robustness of the emergence of secondary flows in a two-layer fluid system.
Philo's Exposition of the Law and His De Vita Mosis
Authors: Goodenough Erwin B. 
Published: October 2011

The problem of Philo's Exposition of the Law and of its relation to the treatise De vita Mosis has, it seems to me, not yet been solved.The Exposition is one of Philo's three great series of commentaries on the Pentateuch. It comprised originally De opificio mundi, De Abrahamo, De Isaaco, De Iacobo, De Josepho, De decalogo, De specialibus legibus, De virtutibus, and De praemiis et poenis, of which all are preserved but De Isaaco and De Iacobo.
Contributions of ability and attainment testing in Africa to a general theory of intellect
Authors: Irvine S. H. 
Published: October 2011

SummaryFactor analytic studies in Africa are compared with other cross-cultural investigations into the structure of abilities in different ethnic groups. Similarities and differences are noted; and environmental influences on the acquisition of skills are also summarized. A correlational study of wrong answers to a battery of thirty marker tests given to a group of predominantly Mashona students indicates that efficiency skills of numerical facility and memory remain at the first order of factor extraction, reasoning abilities emerge in second-order analysis, while perceptual styles are present in the third-order level. This study is used to hypothesize, in the
context of African systems of thought, the existence of a primary thought mode that asserts itself in conditions involving repeated errors.
Race, pluralism and nationalism in the British Caribbean
Authors: Oxaal Ivar 
Published: October 2011

SummaryBritish colonialism in the West Indies bequeathed a number of racial problems to the local societies as they attained independence. The colonial policy of administration in a ‘multi-racial’ social system did little to eliminate ethnic barriers dividing the various groups. A comparison of recent political change in Trinidad and Guyana suggests that the relative size of the various ethnic groups, combined with ecological and ideological differences, have all played an important role in determining the differential degree of conflict these two nations have recently experienced. Political leaders, citizenry and social scientists alike have held diverging views over the nature and future of these 'plural' societies. Some analysts have tended to emphasize the cultural and social cleavages while others have been struck by the apparent capacity of disparate cultural traditions to merge into a unique amalgam.
Some social determinants of recent trends in British fertility
Authors: Busfield Joan , Hawthorn Geoffrey 
Published: October 2011

SummaryThe contrast in birth rates in England and Wales between the periods on either side of the peak in 1964 is described and its components discussed. The drop after 1964 is mainly due to a drop in marital fertility at all ages, and especially the youngest. There is, however, as yet no evidence for a fall in the completed fertility of recent cohorts although their birth intervals are clearly lengthening. The mechanisms of such a change are described and their relative importance suggested. It is concluded that ultimate responsibility for the changing tempo of recent British fertility lies with fluctuations in the economic situation of the country.
Biosocial advantages of an adequate birth interval
Authors: Morley David 
Published: October 2011

SummaryThe process of urbanization in the Third World has vastly outstripped the equivalent change in industrialized countries, and also far exceeds the population growth. This urbanization has been associated with the spread of artificial feeding and associated short birth intervals. Although relatively few studies have been undertaken on the effect of length of birth interval, we have good evidence that it is associated with poorer growth, a less satisfactory intellectual development, and a higher mortality. Child health programmes have, up to the present, been only marginally involved in the question of birth interval, although as mentioned this has a considerable effect on the health of the child. In overcoming malnutrition, simple weight charts are now widely accepted as a useful tool by which the adequate growth of the child can be monitored, and in this way malnutrition prevented. These same weight charts can be a useful means of identifying in any community the month in which a woman has a 5% chance of conceiving again. The charts can also be used as a means of recording the dialogue between the health worker and the parents on the most appropriate time interval to separate their children. However, to achieve this the developing countries will need a vast increase in the health personnel they have available. Experience now in a number of countries suggests that the part-time health worker may be particularly appropriate for providing such services.
Appearance of contraceptive steroids in human milk: effects on the child
Authors: Harfouche J. K. 
Published: October 2011

SummaryThe realization that steroidal contraceptives administered immediately after delivery to lactating women may be excreted into milk, and adversely affect the neonate, is a cause for concern. Most investigations on hormonal contraceptives have dealt with the efficacy of ovulation suppression, and systemic side effects, but little is known about the appearance of steroids or their metabolites in milk. Apart from the immediate side effects on the neonate, unforeseen long-term consequences require special consideration. Until research provides us with more information, women should use breast-feeding and IUDs instead of steroidal contraceptives during the first trimester post-partum.
Professional attitudes to breast-feeding
Authors: Liebrich Ursula 
Published: October 2011

We have heard a lot about the promotion of sales of baby food, but we have never analysed the population's readiness to accept such foods, and how that acceptance comes about. Nor have we analysed the role of the doctors or the health professionals. What is it or what should it be ?About a year ago we carried out a study in London on the intention to breast-feed and the success of mothers in breast-feeding (Liebrich & Morley, 1976), at the same time analysing the attitudes of the staff attending these mothers, who should have helped the latter in their breast-feeding. Table 1 shows a trend in the answers given by women who intend to breast-feed disagreeing with such statements as ‘Nowadays it is no longer necessary to put up with the mess of breast-feeding when easily prepared milks are available’ and agreement (among the same group of mothers) with such statements as: ‘Breast milk is the best food for a baby under four months’.
Oestrogen and pregnanediol excretion through childhood, menarche and first ovulation
Authors: Brown J. B. , Harrisson Patricia , Smith Margery A. 
Published: October 2011

SummaryUrinary oestrogen and pregnanediol values were measured in 24 boys and 38 girls between the ages of 2 and 13 years. Longitudinal studies were conducted on eight girls, two of whom collected for periods of 4 and 5 years which included menarche and in one case establishment of ovulation. Highly sensitive assay methods were developed for measuring the very small amounts of oestrone, oestradiol and oestriol and pregnanediol present in the urine of young children. The total oestrogen values were within the submicrogram range of 0·1–0·5 μg/24 hr in the children aged 2–8 years, with no differences seen between the boys and girls. After the age of 8 years, oestrogen values above 1 μg/24 hr began to be encountered and by age 11½ years the majority of subjects were recording oestrogen values above this figure. The rise in the oestrogen values was more rapid in the girls than in the boys. Evidence was presented that a value of approximately 1 μg/24 hr represents the minimum oestrogen production for the initiation of breast development. The oestrogen values were fluctuating with irregular periodicities at all ages and the gradual general rises seen after the age of 8 years could be arrested at any stage for a year or more. Menarche was preceded by marked periodic fluctuations in oestrogen output which peaked above 15 μg/24 hr. In all subjects studied, the initial bleeding cycles were anovulatory as judged by the low pregnanediol values, the usual pattern being one of fluctuating oestrogen production. One subject was studied fully through to the establishment of ovulation, which first occurred 12 months after menarche. The approach of ovulation was indicated by pre-menstrual rises in pregnanediol which increased in amplitude from 0·4 mg/24 hr until finally 2 mg/24 hr was exceeded (the value accepted for ovulation). Evidence was presented that the interval from menarche to ovulation in different individuals was very variable, extending from ovulation at menarche itself to periods of more than a year. Recording of self-observed symptoms of production of cervical mucus could be of considerable value in documenting these events in larger populations.
Acceptability and use-effectiveness of contraception for teenagers
Authors: Coles Ruth 
Published: October 2011

There is a mass of evidence supporting the belief that adolescents are sexually active but do not use contraception, or do not use it effectively. There are a number of factors which may account for this:(1) a belief in spontaneous behaviour; (2) lack of acceptance of their sexuality by themselves and by others, especially their parents and their teachers; (3) inadequate sex education; (4) inhibitions about obtaining contraception and actual difficulties encountered.These headings are very arbitrary since all these factors are inter-related and it is difficult to know where to start.
The biological basis of aptitude: the endurance runner
Authors: Williams Clyde 
Published: October 2011

SummaryAptitude for a particular sport is governed by many factors, not least of which are obvious environmental influences. There are, however, individuals who, through genetic endowment, have the necessary biological characteristics which identify them as potentially elite athletes. These characteristics have been described more fully for endurance athletes because prolonged, almost steady-state running, lends itself more readily to investigation by biologists, than do the more complex sports.These studies show that the potentially elite endurance athlete is an individual endowed with an above average cardio-respiratory system, capable of a high rate of oxygen transport and carbon dioxide elimination. Not only does the elite endurance athlete have a greater rate of oxygen transport than the average sportsman or sportswoman, but the muscles receiving the oxygen are composed mainly of type I, i.e. low-twitch oxidative fibres, which are designed for endurance exercise. Furthermore, the elite endurance athlete also appears to be pre-programmed genetically to lay down less fat, in the form of sub-cutaneous adipose tissue, than the average sportsman or sportswoman of the same age and sex.Although genetic endowment dictates the potential ability of an individual for sustained high speed running, only appropriate training will allow the realization of this potential and so enable the individual to join the fraternity of the world's elite endurance athletes.
The demography of ethnic minorities
Authors: Coleman David 
Published: October 2011

Cultural—‘ethnic’—differences within national populations have recently become the focus of considerable academic and political debate. This paper considers their demographic significance and reviews some facts and theories on the demography of minorities.It cannot present a comprehensive theory of the demography of ethnic minorities. Such a theory must be part of a more general analysis of cultural effects on demographic variables—which so far is lacking in demography. Neither can it review exhaustively the facts of minority demography; they are not collected or made available in sufficient detail from many countries with minority or multiple nationalities. The aims of the paper are accordingly less ambitious: to consider the political and academic import of minority demographic differences, formulate questions that might usefully be asked about them, and present a few examples in detail.
Genetic assimilation in ethnic minorities
Authors: Hiorns R. W. 
Published: October 2011

Broadly, genetic assimilation may be taken to mean the process by which groups acquire similar genes to one another. In the case of ethnic minorities, this usually involves a minority group and the surrounding majority population. Our knowledge of the genetics of human populations is imperfect and we may declare that only a small fraction of the total set of genes we possess may be identified. These genes may be divided into three subsets:(1) genes which are known and have known effects upon characteristics of those who possess them;(2) genes which are known and may be identified but have no known effects;(3) genes which are unknown, presumed to be awaiting discovery.
Biased sex ratio and niche restriction in Baruscapillaria obsignata (Madsen 1945) (Nematoda, Capillariidae) from Columba livia (Aves, Columbidae)
Authors: D'Ávila S. , Bessa E.C.A. , Souza-Lima S. , Rodrigues M.L.A. 
Published: October 2011

AbstractIn the present study populations of the avian nematode species Baruscapillaria obsignata are described from Columba livia. Male and female individuals were obtained from 27 birds, fixed in alcohol/formalin/acetic acid (AFA) and preserved in 70% ethanol. Nematodes were identified and then counted under a stereoscopic microscope. Baruscapillaria obsignata were much more frequent in the anterior third of the small intestine, and females were more abundant than males in all infra populations. The prevalence was 55.6%, mean intensity was 11.8 (median 11.0; range 1–31) and abundance 6.56. In the present study, we observed an aggregated distribution of parasite infrapopulations, as demonstrated by the value of the exponent of the negative binomial distribution, K = 0.2773; by the discrepancy index, D = 0.656 and by the variance/mean ratio, 12.44. The female/male sex ratios found in all infrapopulations were always greater than 1, showing a bias in favour of female abundance. This tendency was especially marked in infrapopulations containing fewer individuals. The sizes of infrapopulations ranged from 5 to 31 individuals. The mean sex ratio observed was 2.69 ± 3.28 (median 1.83; range 0–11). In infrapopulations with 5–15 individuals, the sex ratios observed varied from 2.6 to 11, while in those with 17–31 individuals, the sex ratios were lower, ranging from 1.7 to 2.4. There was a negative correlation between the intensity of infection and the sex ratio of infrapopulations. Results are discussed in terms of possible factors influencing the processes that lead to niche restriction and biased sex ratios in parasite infrapopulations.
Implicit and explicit knowledge in second language acquisition
Authors: REBUSCHAT PATRICK , WILLIAMS JOHN N. 
Published: October 2011

ABSTRACTLanguage development is frequently characterized as a process where learning proceeds implicitly, that is, incidentally and in absence of awareness of what was learned. This article reports the results of two experiments that investigated whether second language acquisition can also result in implicit knowledge. Adult learners were trained on an artificial language under incidental learning conditions and then tested by means of grammaticality judgments and subjective measures of awareness. The results indicate that incidental exposure to second language syntax can result in unconscious knowledge, which suggests that at least some of the learning in this experiment was implicit. At the same time, however, it was also found that conscious (but unverbalizable) knowledge was clearly linked to improved performance in the grammaticality judgment task.