bluuebunny/crossref_metadata_2025 huggingface dataset:
Oblique projections and standard‐form transformations for discrete inverse problems
Authors: Hansen Per Christian
Published: October 2011

This tutorial paper considers a specific computational tool for the numerical solution of discrete inverse problems, known as the standard‐form transformation, by which we can treat general Tikhonov regularization problems efficiently. In the tradition of B. N. Datta's expositions of numerical linear algebra, we use the close relationship between oblique projections, pseudoinverses, and matrix computations to derive a simple geometric motivation and algebraic formulation of the standard‐form transformation. Copyright © 2011 John Wiley & Sons, Ltd.
On the solution of a quadratic vector equation arising in Markovian Binary Trees
Authors: Bini Dario A. , Meini Beatrice , Poloni Federico
Published: October 2011

We present some advances, both from a theoretical and a computational point of view, on a quadratic vector equation (QVE) arising in Markovian Binary Trees. Concerning the theoretical advances, some irreducibility assumptions are relaxed, and the minimality of the solution of the QVE is expressed in terms of properties of the Jacobian of a suitable function. From the computational point of view, we elaborate on the Perron vector‐based iteration proposed in [Meini and Poloni, A Perron iteration for the solution of a quadratic vector equation arising in Markovian binary trees]. In particular, we provide a condition that ensures that the Perron iteration converges to the sought solution of the QVE. Moreover we introduce a variant of the algorithm that consists of the application of the Newton method instead of a fixed‐point iteration. This method has the same convergence behavior as the Perron iteration, namely it tends to converge faster for close‐to‐critical problems. Moreover, unlike the Perron iteration, the method has a quadratic convergence. Finally, we show that it is possible to alter the bilinear form defining the QVE in several ways without changing the solution. This modification has an impact on convergence speed of the algorithms. Copyright © 2011 John Wiley & Sons, Ltd.
Carbon nanotube‐filled ethylene/vinylacetate copolymers: from in situ catalyzed polymerization to high‐performance electro‐conductive nanocomposites
Authors: Gorrasi Giuliana , Bredeau Stéphane , Candia Chiara Di , Patimo Giovanni , Pasquale Salvatore De , Dubois Philippe
Published: October 2011

Preparation and analysis of morphology, mechanical, and electrical properties of nanocomposites based on ethylene vinyl acetate (EVA) copolymer and commercial multiwalled carbon nanotubes (CNTs) was achieved. The used techniques for obtaining nanocomposites were the conventional melt‐mixing and the in situ ethylene polymerization/coating reaction, as catalyzed directly from CNT surface, with different polyethylene content (i.e. 55.0% and 66.6%). Nanocomposites were also prepared using crude CNTs. The incorporation in the molten state of such polyethylene surface‐coated CNTs, used as “masterbatch,” in EVA was demonstrated a good strategy for allowing the complete destructuring of the native bundle‐like aggregates, leading to the preparation of polymer nanocomposites with largely improved properties, even at very low nanofiller content. Copyright © 2011 John Wiley & Sons, Ltd.
Omnis cellula e cellula revisited: cell biology as the foundation of pathology
Authors: Wright Nicholas A , Poulsom Richard
Published: October 2011

This 2012 Annual Review Issue of The Journal of Pathology argues strongly that cell biology, in its many disciplines, underpins the foundation of our understanding of the mechanisms of disease—the holy grail of pathology. Our increasing knowledge of the human genome will not be enough to attain this goal without parallel developments in our comprehension of the results, at the cellular level, of these genetic changes. In the end, it is cell biology and cell biologists who will deliver this mission. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Exercise intervention for management of obesity
Authors: Deusinger Susan S.
Published: October 2011

Obesity touches the lives of most Americans regardless of age. In adults, accrual of co‐morbidities, including frank disability, impacts health in ways that mandate aggressive public health action. In children, the rising prevalence of overweight and obesity raises serious prospective concerns for life as these children enter adulthood. Action is imperative to provide medical interventions and preventive strategies to reduce the threat this condition poses to future generations. Obesity primarily results from an energy regulation imbalance within the body; understanding its origin and effects requires considering both the intake (via eating) and output (via moving) of energy. This article focuses on how exercise and physical activity (i.e., energy output) can influence the primary condition of obesity and its health sequelae. Components, strategies, and expected outcomes of exercise and lifestyle activity are addressed. Successful long‐term participation in daily movement requires matching exercise regimens and physical activity outlets to individual preferences and environmental conditions. Activity habits of Americans must change at home and in the workplace, schools and the community to positively influence health. Although the goals of Healthy People 2010 to reduce sedentary behavior have not been met, success of other public health interventions (e.g., immunizations, use of bicycle helmets) suggests that social change to alter activity habits can be achieved. Failure to reach our public health goals should serve as a catalyst for broad‐based action to help children, adolescents, and adults attain and maintain behaviors that reduce the risk of obesity and its health insults. Pediatr Blood Cancer 2012; 58: 135–139. © 2011 Wiley Periodicals, Inc.
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

Intoduction

Rhubarb 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.

Objective

The 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.

Methodology

Quantitative 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.

Results

All 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%.

Conclusion

A 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

This 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

The 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

By 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

In 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.

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(© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Work and Fun on the Internet: The Effects of Utilitarianism and Hedonism Online
Authors: Scarpi Daniele
Published: October 2011

Consumers may act on the spur of the moment, driven by fun and curiosity, or be goal-oriented, task-focused utilitarians. This study investigates the effects of consumers’ hedonic and utilitarian orientation online on price consciousness, frequency of purchase, purchased amount, intention to re-patronize a Web site and expertise with the Internet. It specifically considers purchasing, not mere browsing, basing on data collected on customers of one of the largest Italian online retailers for electronics. The data show significant differences between hedonic and utilitarian orientation online with regard to past purchase frequency, the amount purchased and the intention to re-patronize the Web site in the future. The findings suggest that utilitarianism is strongly present online, and is valuable, thus utilitarian consumers should not be neglected, but hedonism is even more profitable, impacting on the number of items purchased and the intention to come back to the Web site. No differences are found in the level of price consciousness or in the degree of expertise with the Internet.
Eddies and interface deformations induced by optical streaming
Authors: Chraibi H. , Wunenburger R. , Lasseux D. , Petit J. , Delville J.-P.
Published: October 2011

We 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.
Leontius of Byzantium and his Defence of the Council of Chalcedon
Authors: Rees Silas
Published: October 2011

The contribution to christology made by Leontius of Byzantium (fl. 520–543 A.D.) lies in his doctrine that the manhood of Christ is ‘enhypostatic’ (ἐνυπόστατος)—the doctrine of Enhypostasia or Inexistence. The Council of Chalcedon (451) defined the person or hypostasis of Christ as consisting in the union of two perfect natures, the nature of God and the nature of man, without division or confusion. On the principle laid down by Aristotle and accepted by all disputants, that there can be no such thing as a nature or substance without hypostasis (ϕύσις, οὐσία ἀνυπόστατος), the question arises of how it possible to avoid the conclusion of two hypostases, corresponding to the two perfect natures, in Christ. Such was the problem set by the definition of Chalcedon and the logic of Aristotle.
The Nature of the Church
Authors: Sperry Willard L.
Published: October 2011

The perennial debate as to the nature of the church must always seem to those who are more interested in ideas than in institutions one of the irrelevancies with which theology is so often charged. It is not the church that matters, but religion.
Toward a Valid View of God
Authors: Meland Bernard E.
Published: October 2011

Liberal Christians have affirmed their faith in religious certainty on the strength of two basic claims: namely, that Jesus revealed the character of God—a morally good God; and that Jesus revealed God's purpose for the world—a morally perfect humanity in accord with God's own character. The outlook of liberal Christianity, embracing both its theology and its ethical program, centres in its certainty concerning these two doctrines which form its sources.
The Apocalypse of Paul and the ‘Iranische Erlösungsmysterium’
Authors: Kraeling Carl H.
Published: October 2011

Among New Testament apocrypha few have been more consistently neglected by modern scholarship than the so-called Apocalypse of Paul. This represents a strange reversal in the fortunes of the book, since at one time it ruled an almost universal favorite. Diverse tokens of this its original popularity still exist. The first will be found in the multiplicity of its ancient versions, manuscripts of which have been coming to light with some regularity since the eighteenth century, when Assemani indicated the existence of Syriac and Arabic codices in the Vatican Library.
The Athos Codex of the Georgian Old Testament
Authors: Blake Robert P.
Published: October 2011

Georgian literature, if it must yield the palm to the Armenian for extent and variety of content, is in at least one respect distinctly superior to its neighbor. A large body of extremely ancient manuscripts have survived, which have preserved to us a highly diversified series of texts. And in general the oldest Georgian manuscripts usually contain the most valuable material. This is true of the Old Testament; the most complete, and on the whole the best, surviving manuscript of that is likewise the oldest. About this manuscript much has been written, but hardly anything has been published from it, and, strangely enough, no detailed description of it has ever appeared. The account herewith presented rests on a careful personal study of the entire codex in the original and in photographs.
The Serabit Expedition of 1930: III. The Temple of Hathor
Authors: New Silva
Published: October 2011

On one of the relatively flat projections of the plateau which forms the top of the mountain of Serabit el-Khadim, three days’ journey by camel from the nearest point of the coast into the interior of the peninsula of Sinai, stand the ruins of the Temple of Hathor. Near it are turquoise mines exploited by the Egyptians from the third to the eighteenth dynasties, and probably also worked intermittently by the local tribes. But the mines were not the raison d'être of the temple, although the goddess of the temple was certainly worshipped by the miners. In the Wadi Maghara also there are Egyptian turquoise mines, and until they were either destroyed or taken away to museums there were inscriptions, carved to record Egyptian expeditions to them. But there is no temple at Maghara.
A Further Note on the Mote and the Beam (Matt. vii. 3–5; Luke vi. 41–42)
Authors: King George Brockwell
Published: October 2011

In the Expository Times for November 1927 Dean C. A. Webster revived an explanation of the saying of Jesus on the mote and the beam made by Karl Furrer (Zeitschrift für Missionskunde und Religionswissenschaft, 1890). Furrer held that we have in the saying of the mote and the beam an incorrect Greek translation of an Aramaic word which signified both ‘eye’ and ‘well,’ and that the Greek translator made a mistake and chose the former instead of the latter meaning. Webster offers an argument in support of this contention, which, again, is combatted by P. L. Hedley in the Expository Times for June 1928.
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.
The Serâbît Inscriptions: II. The Decipherment and Significance of the Inscriptions
Authors: Butin Romain F.
Published: October 2011

Beginning with Flinders Petrie scholars have been struck by the similarity between the script of these inscriptions and the Egyptian hieroglyphs. As the inscriptions were found in the neighborhood of numerous Egyptian monuments, an attempt was naturally made to read them as in the Egyptian language; but this proved unsuccessful, and it was evident that although the signs show close relationship with hieroglyphs, the language is not Egyptian. On Sinai, it was natural to think of a Semitic language. Further, the Egyptian phonetic value of the signs does not yield Semitic words, so that it appears that not only the language but the phonetic value of the signs is Semitic, not Egyptian.
Altheim: Revolutionary or Reactionary?
Authors: Rose H. J.
Published: October 2011

It is no longer possible for any serious researcher on the religion of ancient Rome, and especially on what may be called its proto-history (the regal period and the beginning of the Republic) to ignore the work of Franz Altheim and the little group of colleagues who, with him, form what may perhaps be called the Frankfurt school. The present writer has seen no full-length criticism of his work as a whole, though more than one article has appeared dealing with particular points on his or his colleagues' theories. This essay is an attempt to describe and evaluate his attitude, avoiding, save for the sake of illustration, discussion of details which may be right or wrong without seriously affecting the estimate of his work in general.
Early Orphism and Kindred Religious Movements
Authors: Nilsson Martin P.
Published: October 2011

Orphism is more famous and more debated than any other phenomenon of Greek religion. A central place in the stream of religious ideas is assigned to it, and it is regarded as the source of conceptions of the greatest importance in later times. A vast Orphic literature has existed since early times. Orphism was the first Greek religion to have sacred books, and this is perhaps the ultimate, if unconscious, reason why the scientific treatment of Orphism tends to disclose a system of Orphic doctrines. This is true of Lobeck's masterly work and of the impressive chapter on Orphism in Rohde's Psyche which more than anything determined the views of recent scholars. It is also true of the very ingeniously written and admirably constructed parts of Miss Harrison's Prolegomena which are devoted to Orphism; her treatment is much more copious than Rohde's and she covers a much wider field.
Some ‘Western’ Variants in the Text of Acts
Authors: Bacon Benjamin W.
Published: October 2011

In his article published in the issues of the American Journal of Theology for January and April 1919 (Vol. XXIII), under the title ‘Fact and Fancy in Theories Concerning Acts,’ my respected colleague Professor Charles C. Torrey appears to resent my characterization as “philological” of the type of criticism displayed in his able articles. The term, however, bears no disparaging connotation, and was not so intended. It was, and will be, employed by the present writer simply to distinguish a particular mode of approach to this outstanding problem of New Testament criticism. The mode chosen by Torrey to the exclusion of all others is ‘philological,’ as distinguished from the mode exemplified in the ‘historical’ (or, as Torrey prefers to call it, the “theologico-conjectural”) type represented by such scholars as Harnack, Schürer, Windisch, Preuschen, Loisy, and others. The present reply to his strictures has been long delayed, awaiting Ropes's “Text of Acts” in Volume III of “The Beginnings of Christianity,” in which the long-debated question of the ‘Western’ Text is discussed with what may be hoped to be advance toward its settlement, If in the present essay the type of criticism which Torrey brings to the common problem is still designated ‘philological,’ it must be understood that the term implies no minimizing of Torrey's great attainments in the fields both of textual and higher criticism.
Contributions of ability and attainment testing in Africa to a general theory of intellect
Authors: Irvine S. H.
Published: October 2011

Factor 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 as a social category
Authors: Rex John
Published: October 2011

When the United Nations Organization was set up in 1945, one of its first intellectual tasks was to define the problem of racism which had been one of the major factors in Hitler's rise to power and the subsequent devastation of Europe. Hence UNESCO asked a group of biologists and social scientists to draw up a statement in 1949. The original statement and a further version in 1951 proved, however, to be ambiguous and unsatisfactory in certain respects and the Director-General of UNESCO therefore called upon biologists to meet separately in Moscow in 1964 and for their meeting to be followed by a meeting of biologists, social scientists and lawyers which would then address itself to the specific sociological problem of racism.
Race, pluralism and nationalism in the British Caribbean
Authors: Oxaal Ivar
Published: October 2011

British 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.
The Galton Lecture 1969: Women in academic life
Authors: Kenyon Kathleen M.
Published: October 2011

I do not believe that I am the right person to give this Galton Lecture. I am not in the least a dyed-in-the-wool woman academic. To be that one has to have been man-and-boy in the job. Most of my colleagues at Oxford and sister colleagues at Cambridge could have given the lecture much better. Having written this introductory sentence, it was borne in on me that there were two separate breeds (I am not quite sure whether in this scientific milieu I should say species or genera) of academic women. At Oxford and Cambridge, at Durham, and up to recently in London, there has been the phenomenon (I cannot, in fact, think of any other classificatory term, for obviously one cannot use either breed or species or genera in the generally accepted sense about a single-sex organization) of associations of undiluted women academics, associations to be diluted by about 1972. In other universities, the female of the species is absorbed in the whole. Again, having reached this stage in my meditations, my sense of inadequacy in my present situation is slightly mitigated by the fact that I have at least had some experience of a community in which sex-differentiation was nominally not observed. Between my period as an Oxford undergraduate and my past 7 years as Principal of an Oxford women's college, I had 27 years at the University of London, though I must admit it was at an eccentric and utterly atypical institution.
Environmental influences on human fertility
Authors: Parkes Alan S.
Published: October 2011

The word environment is here used to mean the total environment, physical and social, which for man means primarily the climatic and cultural conditions under which he lives and breeds. Fertility is used in the demographic sense of reproductive performance as contrasted with fecundity, or potential reproductive capacity.
Biosocial aspects of multiple births
Authors: Nylander P. P. S.
Published: October 2011

Owing to the rarity of triplets and higher multiple births, most studies of multiple births have been focused on twins. One of the fields of study which has attracted considerable interest is the association of biosocial factors with twinning. Although much work has been done in this field in Caucasian populations, very little investigation has been carried out in tropical areas, some of which have the highest twinning rates on record. In this paper, the results of recent studies on twinning conducted in Aberdeen (Scotland) and Ibadan (Nigeria) will be presented to illustrate the influence of some biosocial factors on twinning.
Some social determinants of recent trends in British fertility
Authors: Busfield Joan , Hawthorn Geoffrey
Published: October 2011

The 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

The 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

The 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

Urinary 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 menopausal transition: endocrinological and epidemiological considerations
Authors: Sherman Barry M. , Wallace Robert B. , Treloar Alan E.
Published: October 2011

The human menstrual cycle is characterized by a series of dynamic hormonal relationships that result in the regular maturation of ovarian follicles, ovulation and corpus luteum formation. As methodology has changed and improved, it has become possible to examine these events in greater detail. The simple analysis of menstrual cycle length, when done with care in a large number of women over long time spans, has revealed much about the fundamental biological rhythm of the menstrual cycle. Of particular interest are the predictable changes in cycle length and variability that occur at different stages of reproductive life (Treloar et al., 1967; Vollman, 1977). Basal body temperature records add another dimension to the analyses of menstrual cycle length because they permit estimation of the length of the pre- and post-ovulatory phases of the menstrual cycle and provide some index of the integrity of corpus luteum function.
Patterns of fertility at later ages of reproduction
Authors: Leridon Henri
Published: October 2011

This paper discusses some of the things that demographers know about fertility at later ages of reproduction in developed countries. The nature of the information available through, for example, vital statistics is often a product of history and of administrative requirements, rather than the result of a well-based scheme. Surveys are frequently used to fill the gaps in major sources, but no survey appears to have been carried out specifically on the topic under discussion here. The available information will be discussed under four broad headings: (1) the levels and the trends of late fertility, as compared with fertility at younger ages; (2) the specific characteristics of mothers giving birth at later ages; (3) the specific characteristics of the corresponding births, and the risks for pregnancies at older ages; (4) the question of whether these births are less wanted than others.
The role of the media in sport
Authors: Morgan Cliff
Published: October 2011

The part played by radio and television coverage of sport in developing public appreciation of sports is covered, and consideration is given to the responsibilities involved in dealing with sports in which violence occurs. The duties of the television producer in relation to the players, the viewers and the sponsors of sport are discussed.
The biological basis of aptitude: the endurance runner
Authors: Williams Clyde
Published: October 2011

Aptitude 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.
Citius, altius, fortius?
Authors: Williams John
Published: October 2011

Factors leading to improvements in human sports performance are considered. The positive and negative effects of social and economic changes and the application of scientific and technological developments are discussed.
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.
Measuring the impact of health interventions on mortality in developing countries: why bother?
Authors: Graham Wendy
Published: October 2011

Measuring the mortality impact of health interventions is not straightforward; there is now ample evidence of this. So why bother? Clearly, the utility, sensibility and feasibility of measuring the mortality impact of health interventions depend on many factors, which makes it difficult to offer simple prescriptions. The failure of those demanding measurement to appreciate this has led, on the one hand, to the proliferation of largely unsubstantiated claims on the achievements of health interventions and, on the other hand, to disillusionment about the prospects of demonstrating any impact on mortality. It is not difficult to account for the complexity of this area nor the current state of uncertainty. Progress has largely reflected developments in its three components—mortality measurement, health research and programme evaluation. It is thus not surprising to find the almost exclusive emphasis on measuring impact on infant and child mortality; in developing countries, child health is given a high priority in the allocation of resources by governments and donor agencies, and the techniques for estimating child mortality are generally more advanced.
Oral rehydration therapy and its effect on child mortality in Egypt
Authors: Rashad Hoda
Published: October 2011

A major Egyptian national programme for the control of diarrhoeal disease was launched in February 1984, with the aim of reducing the dehydration-specific mortality resulting from acute diarrhoea (52% of all infant deaths in 1979) and thus to reduce overall infant and childhood mortality.
Physicochemical, microbiological and sensory profiles of fermented milk containing probiotic strains isolated from kefir
Authors: Kakisu Emiliano , Irigoyen Aurora , Torre Paloma , De Antoni Graciela L , Abraham Analía G
Published: October 2011

A two-strain starter culture containing Lactobacillus plantarum CIDCA 83114, a potential probiotic strain isolated from kefir grains, and Streptococcus thermophilus CIDCA 321 was tested for the preparation of a fermented milk product. Kluyveromyces marxianus CIDCA 8154, a yeast with immunomodulatory properties was included to formulate a three-strain starter culture. Supernatants of enterohaemorragic Escherichia coli, shiga-toxin–producing strain, along with a two-strain or a three-strain starter culture were included in the medium of Vero-cell surface cultures. The results demonstrated that these combinations of microorganisms antagonize the cytopathic action of shiga toxins. The cell concentration of Lb. plantarum did not decrease during fermentation, indicating that the viability of this strain was not affected by low pH, nor did the number of viable bacteria change during 21 days of storage in either fermented products. The number of viable yeasts increases during fermentation and storage. Trained assessors analyzed the general acceptability of fresh fermented milks and considered both acceptable. The milk fermented with the two-strain starter culture was considered acceptable after two week of storage, while the product fermented with the three-strain starter culture remained acceptable for less than one week. The main changes in sensory attributes detected by the trained panel were in sour taste, milky taste and also in fermented attributes. The correlation between different sensory attributes and acceptability indicated that the panel was positively influenced by milky attributes (taste, odour, and flavour) as well as the intensity of flavour. In conclusion, the two-strain starter culture would be the more promising alternative for inclusion of that potential probiotic lactobacillus in a fermented milk product.