bluuebunny/crossref_metadata_2025 huggingface dataset:
Before crossing over: the advantages of eukaryotic sex in

genomes lacking chiasmatic recombination
Authors: ANTEZANA MARCOS A. , HUDSON RICHARD R.
Published: July 2002

Non-recombining populations should suffer from four classic population

genetic disadvantages: (1)

they cannot reverse Muller's Ratchet, the accumulation of

deleterious mutations caused by genetic

drift and mutation; (2) whenever the fix a favourable mutation they lose

all unlinked favourable

variants; (3) they tend to lose favourable mutations that are linked to

deleterious mutations; and

(4) their genetic loads can be quite high when deleterious mutations have

synergistic effects. It is

commonly assumed that inter-chromosomal recombination (independent assortment)

can counter

these phenomena, but this has been studied only for the genetic load case.
In

contrast, many

studies have shown that recombination via crossing over can counter these

phenomena. Here we

first show that segregation alone can strongly decelerate Muller's

Ratchet in diploids, i.e. that

recombination is not the only way to do so. We then show that

inter-chromosomal recombination

can indeed deal with phenomena (1) to (3) above very effectively if the

genome consists of a

moderate number of chromosomes. Therefore, if the above advantages of

genetic recombination

played a large role in the initial success of eukaryotic sex, the crucial

moment in the origin of sex

might have been the evolution of inter-chromosomal recombination, i.e.

the evolution of genome

segmentation, segregation, and syngamy. Crossing over might have become

established as a major

recombinational device only later, eliminating the disadvantages of

extensively segmented genomes.
Measuring fitness by means of balancer chromosomes
Authors: BARTON N. H. , PARTRIDGE L.
Published: July 2002

We present the theoretical background to a new method for measuring genetic variation for total
fitness in Drosophila. The method allows heterozygous effects on total fitness of whole wild-type
chromosomes to be measured under normal demography with overlapping generations. The wild-type chromosomes are competed against two balancer chromosomes (B1, B2, say), providing a
standard genotype B1/B2 against which variation in the fitness effects of the wild-type
chromosomes can be assessed. Fitness can be assessed in two ways: (i) at equilibrium of all three
chromosomes under heterozygote advantage, and (ii) during displacement of one balancer by the
other. Equilibrium with all three chromosomes present will be achieved only if the wild-type
homozygote is not too fit, and if the fitnesses of the three heterozygotes are not too unequal. These
conditions were not satisfied for any of a sample of 12 lethal-bearing chromosomes isolated from a
random-bred laboratory population of Drosophila. At equilibrium, genotypic frequencies show low
sensitivity to changes in genotypic fitness. Furthermore, where all four genotypes are viable and
fertile, supplementary information from cages with only two chromosomes present and from direct
measurements of pre-adult viability are required to estimate fitnesses from frequencies. The
invasion method has the advantages of a greater sensitivity and of not requiring further data to
estimate fitnesses if the wild-type homozygote is fertile. However, it requires that multiple samples
be taken as the invasion progresses. In a discrete generation model, generation time influences
fitness estimates from this method and is difficult to estimate accurately from the data. A full age-structured model can also be applied to the data from both types of experiment. For the invasion
method, this gives fitness estimates close to those from the discrete generation model.
The Dead Sea Fault and related subsurface structures,
Gaziantep Basin, southeast Turkey
Authors: COSKUN B. , COSKUN B.
Published: July 2002

Late Cretaceous and Miocene collisions of the Arabian, Anatolian and Eurasian plates, as
shown by widespread ophiolitic exposures along the suture, created favourable geological conditions
for the formation of the surface and subsurface structures in the Gaziantep Basin, southeast Turkey.
The late Cretaceous (Maastrichtian) emplacement of the Kocali–Karadut ophiolite complex induced
subsidence in the northwestern zone of the Kastel Basin during the early Alpine Orogeny and influenced
the structural evolution of the foreland area. The Dead Sea Fault, which originated in the Red
Sea in Miocene time, propagated towards the northwest in the Suez Gulf and the north-northeast in
southeast Turkey, and influenced the structural evolution of the Gaziantep Basin. These two major
tectonic events produced many thrusts, thrust-related subsurface and surface anticlines, faults, fractures,
flower structures and basaltic flows in the area. Geological and geophysical investigations indicate
the existence of two important structural phases. The older structures were formed during the late
Cretaceous movements, but they have been reactivated by latest Miocene tectonic activities with
appearance of the Strands of the Dead Sea Fault in the sedimentary basin. The geothermal studies
show also that, as a result of the Tertiary transgressions and volcanic activity, the northern and southern
sectors of the Gaziantep Basin underwent differing subsidence and structural histories.
Plio-Pleistocene alluvial architecture in marginal extensional
narrow sub-basins: examples from southwest Greece
Authors: ZELILIDIS ABRAHAM , KONTOPOULOS NIKOLAOS
Published: July 2002

At the eastern margin of the southern part of the northwest-trending Kalamata Basin, four
small extensional sub-basins were formed during the Plio-Pleistocene period. These sub-basins
developed on the footwall of a major north-northwest-trending marginal fault, which separates the
Taygetos mountains from the Kalamata Basin. Two different basin configurations, mostly resulting
from different subsidence/sedimentation ratio (R), produced two different depositional types. In the
first type, where R>1, gravelly alluvial fans were deposited in narrow and restricted sub-basins. In the
second type, where R<1, braid-deltas were deposited in open, low-gradient sub-basins with marine
influence. Braid deltas consist mostly of sandstone and mudstone, and only in the northern part of
one sub-basin did gravel accumulate. The paucity of gravel is associated with rapid basin subsidence.
Since factors such as climate and source-rock lithologies were essentially similar for the different
basins, these different alluvial stratigraphies result principally from tectonic processes. Maximum sediment
thickness formed on the hangingwall of faults parallel to the major basin-margin fault. Transfer
faults at right angles to this major fault have strongly influenced the pathways of braided low-sinuosity
streams. The initial open-channel width-to-depth ratio of the channels in this study (range 5–20) is
comparable to suspended load channels and channel-fill deposits.
PRIVATE PROPERTY, PUBLIC INTEREST, AND THE ROLE OF THE STATE IN NINETEENTH-CENTURY BRITAIN: THE CASE OF THE LIGHTHOUSES
Authors: TAYLOR JAMES
Published: July 2002

Until 1836, many of England's lighthouses were privately owned. The owners levied tolls on all merchant shipping which made use of the lights, and in many cases grew rich from the proceeds. After 1815 these profits became increasingly contentious, and, under pressure from shipowners, merchants, and the radical MP Joseph Hume, the whig government abolished private ownership of lighthouses and made Trinity House the sole lighthouse authority for England. The choice of Trinity House as the central administration from a range of alternatives made a UK-wide authority impossible, however, due to the unwillingness of Irish and Scottish MPs to see their national boards replaced by an ‘inferior’ English one. The reform process sheds light on contemporary perceptions of the relationship between private property and public interest and suggests that alongside the process of post-war retrenchment, the state was acquiring a new role as guardian of the public interest, often positioning itself against certain forms of private property. Behind the ‘old corruption’ rhetoric which characterized the demand for reform lay the conviction that certain resources should be excluded from the realm of private property by the state, and that private profit made at the expense of the public interest was morally wrong.
THE TRANSFORMATION OF EIGHTEENTH-CENTURY AMERICA
Authors: MIDDLETON SIMON
Published: July 2002

Contested boundaries: itinerancy and the shaping of the colonial
American religious world. By Timothy D. Hall. Durham: Duke University Press, 1994.
Pp. x+196. ISBN 0-8223-1522-X. £10.97.

Original meanings: politics and ideas in the making of the Constitution.
By Jack N. Rakove. New York: Alfred A. Knopf, 1996. Pp. xvi.+439.
ISBN 0-394-57858-9 £19.26.

Parades and the politics of the street: festive culture in the early American
republic. By Simon P. Newman. Philadelphia: University of Pennsylvania Press, 1997.
Pp. xiv+271. ISBN 0-8122-3399-9. £24.42.

Transatlantic radicals and the early American republic. By Michael Durey.
Kansas: University of Kansas, 1997. Pp. xi+425. ISBN 0-7006-0823-0 £25.71.
SHIREEN T. HUNTER, The Future of Islam and the West: Clash of Civilizations or Peaceful Coexistence (Westport, Conn.: Praeger, 1998). Pp. 210. $55.00 cloth, $17.95 paper. BASSAM TIBI, The Challenge of Fundamentalism: Political Islam and the New World Disorder (Berkeley: University of California Press, 1998). Pp. 262. $29.95 cloth.
Authors: Keddie Nikki R.
Published: July 2002

Shireen T. Hunter and Bassam Tibi have both written thoughtful and useful books about the current Islamic political phenomenon, which complement and do not duplicate each other. Hunter presents a realistic, readable, and analytical argument showing, among other things, that the foreign policies of Islamic states are only to a small degree influenced by Islam and are much more determined by considerations of foreign and domestic interest, however Islamic the government may claim to be. She also demonstrates that there has been little unity in the foreign policies of Muslim countries. For both of these reasons, she states that Samuel Huntington's idea of a coming clash of civilizations, centering on the West versus Islam, is not based on reality and is extremely unlikely to come to pass. (Tibi's book is also concerned with disproving Huntington's argument with effective counter-arguments.)
ABDO BAAKLINI, GUILAIN DENOEUX, AND ROBERT SPRINGBORG, Legislative Politics in the Arab World: The Resurgence of Democratic Institutions (Boulder, Colo.: Lynne Reinner, 1999). Pp. 287. $59.95 cloth, $22.50 paper.
Authors: Lust-Okar Ellen
Published: July 2002

In Legislative Politics in the Arab World, Abdo Baaklini, Guilain Denoeux, and Robert Springborg provide a long-overdue and important step toward understanding legislative institutions in the Arab world. In the first part of this work, they redirect scholars' attention to Arab legislatures, which they argue both reflect and affect the “dynamics of democratic transition and consolidation in the Arab world” (p. 6). In the second part of the book, they provide detailed case studies of legislative institutions in Egypt, Jordan, Kuwait, Lebanon, Morocco, and Yemen. Throughout the book, they leave us with the simple but important message: “Arab legislatures matter.”
WOMEN WORKING IN OMAN: INDIVIDUAL CHOICE AND CULTURAL CONSTRAINTS
Authors: Chatty Dawn
Published: July 2002

Middle Eastern women have often been portrayed by Westerners as silent shadows or as helpless victims of suppressive customs and traditions who are unable to organize or form groups on their own and for themselves and are prevented from entering fully into the public sector of life. The past decade, however, has seen an explosion in research and publication that fully acknowledges women as people in their own right. Women in the Middle East have come to be seen as political and economic actors who fend for themselves and struggle and reflect on their lives and the future of their societies. Through their actions, the boundary that defines what is traditional cultural behavior and what is contemporary, foreign, or unacceptable is often blurred.1 The patriarchal state, however, fails to recognize the transformative power of women's contemporary behavior, which pushes the definition of “accepted” or “traditional” behavior beyond that found in official documents and local and regional legislation, with their largely male audience.
RIFA⊂A RAFI⊂ AL-TAHTAWI AND HIS CONTRIBUTION TO THE LEXICAL DEVELOPMENT OF MODERN LITERARY ARABIC
Authors: Sawaie Mohammed
Published: July 2002

In the 19th century, Europe had a tangible impact on the Arab East. During this period, Arabic-speaking regions were brought into intimate contact with the West, both through military intrusion (e.g., the French in 1798–1801 and the British in Egypt in 1882), and institutional penetration (e.g., the founding of Western-style schools and higher-education institutions in the Levant in the 1800s by Christian missionaries such as the Syrian Protestant College in 1866, now the American University of Beirut, and [the Jesuit] St. Joseph University, also in Beirut, in 1874). This overpowering European encroachment on the Arab East in the 19th century resulted in cultural and linguistic identity crises. Muhammad ⊂Ali, who ruled Egypt from 1805 until 1848, dispatched groups of students to Western countries such as Italy, Austria, and France to study at their universities and technical institutions. At home, he established schools with Western-language instruction, and sponsored translations of scientific works initially into Turkish, and later into Arabic, from Italian and French, thus making available new disciplines such as various branches of engineering, military science, and agriculture. In 1822, he established a printing press in the Bulaq section of Cairo.1 From then on, Arabicized versions of European terms such as “theater” (tiy―atru), “journal” (jurn―al), “the post” (al-busta), and “politics” (al-bulit―iq―a) signaled the arrival of Western institutions and technology in Arabic-speaking regions, and such terms were adopted by writers in their writings. The cultural, political, military, and technological challenges that resulted from the European contact with the Arab East, and the institutional changes that accompanied them, proved to be a crucial turning point in the development of the Arabic language, particularly its lexicon. However, interest in language matters was central to the Arab renaissance (Nahda) of the 19th century. Arab writers; intellectuals; and translators such Rifa⊂a Rafi⊂ al-Tahtawi (1801/2–73), (Ahmad) Faris al-Shidyaq (1801/04?–87), Nasif al-Yaziji (1800–71), and Butrus al-Bustani (1819–83), among others, debated Arabic linguistic issues in terms of their own literary and linguistic heritage. These and other authors discussed the “internal” needs of Arabic, not only issues of translating the culture of the Western societies. They wrote grammars and compiled other literary textbooks to facilitate the teaching of Arabic and to overcome difficulties of learning the language associated with older, traditional ways of language teaching and to raise awareness of the literary tradition of Arabs. These intellectuals also engaged in the preparation of glossaries and dictionaries appropriate to the needs of their societies.2
MASTER AND SERVANT IN COLONIAL KENYA, 1895–1939
Authors: ANDERSON DAVID M.
Published: July 2002

THE recruitment of African labour at poor rates of pay and under primitive
conditions of work was characteristic of the operation of colonial capitalism
in Africa during the nineteenth and twentieth centuries. The implications of
these conditions have been generalized very widely in the historiography of
colonial Kenya. Where capital was centred upon extractive industries or
upon settler agriculture (as in Kenya), historians have found much evidence
to indicate that colonial states (and the metropolitan government) readily
colluded with capital in providing the legal framework within which labour
could be recruited and maintained in adequate numbers and at low cost to
the employer. The state itself was the largest employer of labour throughout
British colonial Africa and shared an interest in encouraging Africans into
the labour market. Criticisms of labour conditions prevailing in any colony
were thus likely to be interpreted as criticisms of the state itself.
Influences of yearly weather variation and fertilizer
rate on bread-making quality in Swedish grown wheats
containing HMW glutenin subunits 2+12 or 5+10
cultivated during the period 1990–96
Authors: JOHANSSON E. , SVENSSON G.
Published: July 2002

The effects of weather and nitrogen application rate on bread volume, protein concentration and
gluten strength were investigated in spring and winter wheats in Sweden during 1990–96. The
investigation was carried out in wheats containing the high-molecular-weight (HMW) glutenin
subunit combinations 2+12 or 5+10.

The results showed that a warm (c. 20°C mean dry temperature) and dry grain-filling period, as
during 1994 and 1995, led to high gluten strength. As a relatively gentle dough mixing is normally
applied in Sweden when baking bread, excessively high gluten strength results in low bread volumes.
Wheat cultivars containing HMW glutenin subunits 5+10 generally had higher gluten strength than
those containing subunits 2+12. However, not all the cultivars containing subunits 5+10 showed
overstrong gluten properties, whereas some cultivars containing subunits 2+12 were overstrong
during 1994 and 1995. Different cultivars produced the highest gluten strength in different years.
Generally, cultivars containing HMW subunits 2+12 gave higher bread volumes than those
containing subunits 5+10. This is probably due to the Swedish baking method, where the dough is
given a relatively gentle mixing for a fixed period of time.

Increased fertilizer rates led to increased protein concentration and decreased gluten strength.
However, during certain years, for example 1994, the gluten strength was only decreased slightly by
increased fertilizer rates, particularly in cultivars containing HMW glutenin subunits 5+10.
Effects of Striga hermonthica on yield components in maize
Authors: ADETIMIRIN V. O. , AKEN'OVA M. E. , KIM S. K.
Published: July 2002

A split-plot experiment was conducted in 1992 and 1993 at Mokwa in the southern Guinea savanna
zone of Nigeria to determine the responses of maize yield components to infestation by parasitic weed
Striga hermonthica (Del.) Benth. and identify the most important yield components under Striga
parasitism. Infestation treatments (infested v. non-infested) and hybrids [9022-13 (highly tolerant),
8644-31 (moderately tolerant), 8321-21 (moderately susceptible) and 8338-1 (highly susceptible)] were
the main and subplots, respectively.

Striga significantly reduced grain yield and all the yield components considered. Pre-flowering
stress due to Striga parasitism was higher than post-flowering stress and resulted in higher reduction
for ears per plant (44%) than reductions for other yield components (12–29%). The numbers of yield
components for which the hybrids exhibited the highest percentage reduction increased with the
degree of susceptibility to Striga. Thus, 8338-1, the highly susceptible hybrid, suffered more severe
reductions in a larger number of yield components than the other hybrids. Number of ears per plant
was a major yield component and accounted for an overwhelming proportion (R2 = 0·95) of the
variation in grain yield under Striga. Reductions in maize grain yield and its components were more
severe under the moisture stress that occurred in 1992.
FACTORS ASSOCIATED WITH UNFAVOURABLE BIRTH OUTCOMES IN KENYA
Authors: MAGADI MONICA , MADISE NYOVANI , DIAMOND IAN
Published: July 2002

Studies addressing factors associated with adverse birth outcomes have almost exclusively been based on hospital statistics. This is a serious limitation in developing countries where the majority of births do not occur within health facilities. This paper examines factors associated with premature deliveries, small baby’s size at birth and Caesarean section deliveries in Kenya based on the 1993 Kenya Demographic and Health Survey data. Due to the hierarchical nature of the data, the analysis uses multilevel logistic regression models to take into account the family and community effects. The results show that the odds of unfavourable birth outcomes are significantly higher for first births than for higher order births. Furthermore, antenatal care (measured by frequency of antenatal care visits and tetanus toxoid injection) is observed to have a negative association with the incidence of premature births. For the baby’s size at birth, maternal nutritional status is observed to be a predominant factor. Short maternal stature is confirmed as a significant risk factor for Caesarean section deliveries. The observed higher odds of Caesarean section deliveries among women from households of high socioeconomic status are attributed to the expected association between socioeconomic status and the use of appropriate maternal health care services. The odds of unfavourable birth outcomes vary significantly between women. In addition, the odds of Caesarean section deliveries vary between districts, after taking into account the individual-level characteristics of the woman.
ASSESSING POPULATION DYNAMICS IN A RURAL AFRICAN SOCIETY: THE NAVRONGO DEMOGRAPHIC SURVEILLANCE SYSTEM
Authors: BINKA FRED N. , NGOM PIERRE , PHILLIPS JAMES F. , ADAZU KUBAJE , MacLEOD BRUCE B.
Published: July 2002

In 1993, the Navrongo Health Research Centre launched a new demographic research system for monitoring the impact of health service interventions in a rural district of northern Ghana. The Navrongo Demographic Surveillance System uses automated software generation procedures that greatly simplify the preparation of complex database management systems. This paper reviews the Navrongo model for data collection, as well as features of the Navrongo system that have led to its replication in other health research projects requiring individual-level longitudinal demographic data. Demographic research results for the first 2 years of system operation are indicative of a pretransitional rural society with high fertility, exceedingly high mortality risks, and pronounced seasonal out-migration.
Thermal stability of acid proteinases
Authors: WALSH MARIE K. , LI XIAOSHAN
Published: July 2002

Milk-clotting enzymes are used during the production of cheese to coagulate the
casein, allowing the formation of a three-dimensional network that entraps the milk
fat. Commercially available milk-clotting enzymes differ with respect to source,
specificity, optimum pH and thermostability. All are acid proteinases that can cleave
κ-casein resulting in the coagulation of milk. Chymosin (EC 3.4.23.4) is specific for
the Phe–Met bond in κ-casein at the natural pH of milk (6·7). Recombinant chymosin
is available commercially from a variety of sources and has a maximum activity at
40 °C. Recombinant chymosins are purified from the fermentation of recombinant
strains of Aspergillus niger, Asp. oryzae or Kluyveromyces marxianus. These enzyme
preparations are chemically and functionally identical to calf chymosin. Rennets are
purified from the abomasum of bovines and can contain from 60 to 100% chymosin
with the remainder being primarily bovine pepsin (Wigley, 1996). Microbial
proteinases (EC 3.4.23.6) are generally more proteolytic than chymosin, with varying
heat stability. These enzymes liberate more non-protein N from casein and can
cleave α- and β-casein as well as κ-casein at the natural pH of milk. Acid proteinases
from Cryphonectria parasitica are more heat labile than those from Rhizomucor
miehei, which are characterized as thermostable (Ernstrom & Wong, 1974).

The objective of this research was to characterize milk-clotting enzymes with
respect to thermal inactivation in skim milk. This information has applications in
milk and whey processing.
Effect of feed availability on post-milking standing time in dairy
cows
Authors: TYLER JEFF W. , FOX LARRY K. , PARISH STEVEN M. , SWAIN JOHN , JOHNSON DENNIS L. , GRASSESCHI HELEN A. , GANT RODERICK
Published: July 2002

Control programmes for contagious mastitis pathogens, primarily

Streptococcus
agalactiae and Staphylococcus aureus, consisting of milking

hygiene, treatment or
isolation of infected cows and post-milking teat disinfection are relatively

effective
(McDonald, 1970; Natzke, 1977; Fox & Gay, 1993). Similar control programmes
are
often ineffective in the prevention of intramammary infections caused by

environmental bacteria (Eberhart, 1977; Smith et al.
1985; Erskine et al. 1991; Smith
& Hogan, 1993). This disparity of success relates to the fact that
the
principal source of environmental mastitis pathogens is the cow's
environment,
rather than another
cow with an intramammary infection (Eberhart, 1977; Smith et al.

1985). Infections
of environmental origin are particularly noteworthy because they may remain

common in well managed herds, and these infections often cause severe clinical
signs
and high case fatality rates (Eberhart, 1977; Smith et al. 1985;

Erskine et al. 1991; Smith & Hogan, 1993).

Control programmes for environmental mastitis usually include premilking
teat
disinfection, decreased use of water in udder preparation, increased
concentrations of
dietary vitamin E and selenium, improved sanitation of the environment
and
modification of cow behaviour in the post-milking period (Eberhart, 1977;
Smith
et al. 1984, 1985; Weiss et al. 1990; Erskine
et al. 1991; Smith & Hogan, 1993).
Environmental infections are thought to result when bacteria lacking specific

virulence factors penetrate the teat sphincter (Eberhart
et al. 1979; Smith et al.
1985). The bulk of these exposures are thought to occur between milkings.
Control
of these infections is problematic because the cow's teat sphincter

remains open after
mechanical milking (McDonald, 1975a). Presumably, cows are predisposed
to
intramammary infections when the open teat sphincter is exposed when cows
lie
down. Hence, dairy managers are advised to offer fresh feed to cows immediately

after milking to increase the likelihood that the teat sphincter will close
at least
partly before cows become recumbent.

The purpose of this study was to determine the effect of feed availability

on post-milking behaviour in dairy cows. Specifically, the measured
dependent variable was
the length of time that cows remained standing after leaving the milking
parlour.
Managing diet quality for Cheddar cheese manufacturing milk.
2. Pasture v. grain supplements
Authors: CHRISTIAN MARY P. , GRAINGER CHRIS , SUTHERLAND BRIAN J. , MAYES JEFFERY J. , HANNAH MURRAY C. , KEFFORD BRUCE
Published: July 2002

The effects of supplementing a basal diet of silage and hay with increasing
amounts of harvested spring pasture, or with lupin and wheat, on the composition
of milk and the consequent effects on cheese composition and yield were investigated
in an indoor feeding study. Milk was collected from five groups of eight cows in mid
lactation offered different diets and manufactured into Cheddar cheese on a pilot
scale. Milk from cows given the lupin–wheat (LW) and the high pasture level (HP)
diets produced low moisture cheese. Cheese produced with milk from cows given the
control diet was high in moisture content compared with that made with milk from
cows offered the LW diet. Cheese yields from the milk of cows offered the HP and LW
diets were greater than from the milk of cows on the control diet, and were associated
with the higher casein concentrations of these milks. Casein number was higher in
milk from diets supplemented with pasture but was not an indicator of the functional
properties of milk that affected cheese moisture. The proportion of β-casein in milk
from cows offered the HP diet was higher and that of γ-casein lower than in milk
from cows given the LW supplement, although cheese moisture content was similar
with both diets. Milk from cows offered the HP diet had a greater inorganic P
concentration than that from cows given the LW diet, although the dietary intake
of P was higher for the LW diet. The significance of the effect of dietary P intake on
the concentration of inorganic P in milk and hence its suitability for cheesemaking
was apparent when dietary P intake was low, as shown in milk produced by cows
offered the control diet.
Peter's Throne and Augustine's Chair: Rome and Canterbury
from Baldwin (1184–90) to Robert Winchelsey (1297–1313)
Authors: SAYERS JANE
Published: July 2002

The arrival of St Augustine in England from Rome in 597 was an
event of profound significance, for it marked the beginnings of
relations between Rome and Canterbury. To later generations this
came to mean relations between the papacy in its universal role, hence the
throne of St Peter, and the metropolitical see of Canterbury and the
cathedral priory of Christ Church, for the chair of St Augustine was
the seat of both a metropolitan and an abbot. The archiepiscopal see and
the cathedral priory were inextricably bound in a unique way.

Relations with Rome had always been particularly close, both between
the archbishops and the pope and between the convent and the pope. The
cathedral church of Canterbury was dedicated to the Saviour (Christ
Church) as was the papal cathedral of the Lateran. Gregory had sent the
pallium to Augustine in sign of his metropolitan rank. There had been
correspondence with Rome from the first. In Eadmer's account of the old
Anglo-Saxon church, it was built in the Roman fashion, as Bede testifies,
imitating the church of the blessed Peter, prince of the Apostles, in which
the most sacred relics in the whole world are venerated. Even more
precisely, the confessio of St Peter was copied at Canterbury. As Eadmer
says, ‘From the choir of the singers one went up to the two altars (of Christ
and of St Wilfrid) by some steps, since there was a crypt underneath, what
the Romans call a confessio, built like the confessio of St Peter.’ (Eadmer
had both visited Rome in 1099 and witnessed the fire that destroyed the
old cathedral some thirty years before in 1067.) And there, in the confessio,
Eadmer goes on to say, Alfege had put the head of St Swithun and there
were many other relics. The confessio in St Peter's had been constructed
by Pope Gregory the Great and contained the body of the prince of the
Apostles and it was in a niche here that the pallia were put before the
ceremony of the vesting, close to the body of St Peter. There may be, too,
another influence from Rome and old St Peter's on the cathedral at
Canterbury. The spiral columns in St Anselm's crypt at Canterbury,
which survived the later fire of 1174, and are still standing, were possibly
modelled on those that supported St Peter's shrine. These twisted
columns were believed to have been brought to Rome from the Temple
of Solomon. At the end of the sixth century, possibly due to Gregory the
Great, they were arranged to form an iconostasis-like screen before the
apostle's shrine. Pope Gregory III in the eighth century had added an
outer screen of six similar columns, the present of the Byzantine Exarch,
of which five still survive. They are practically the only relics of the old
basilica to have been preserved in the new Renaissance St Peter's.
Visiting ‘Peter in Chains’: French Pilgrimage to Rome, 1873–93
Authors: BRENNAN BRIAN
Published: July 2002

Inscribed on the wall of the expiatory Basilica of Sacré Coeur, at
Montmartre, the 1873 ‘national vow’ of France interprets the
nation's recent misfortunes as divine chastisement of an errant and
irreligious people. Since it was Napoleon III's withdrawal of French troops
from Rome that had made it possible for the Italian forces to capture the
papal city in September 1870, the ‘national vow’ reflects a strong sense
of French responsibility for the pope's loss of his temporal power. The
Catholic Right interpreted France's defeat in the Franco-Prussian war,
and her subsequent loss of Alsace and Lorraine, as God's punishment on
‘the eldest daughter of the Church’ for her desertion of the Vicar of
Christ, and the ‘national vow’ pledged prayer for the Roman pontiff's
deliverance from his enemies. This study analyses the devotion of French
Catholics to ‘the prisoner of the Vatican’ during the Third Republic
through an exploration of some of the religious and political meanings of
pilgrimage to visit ‘Peter in chains’. It also charts the process by which
promotion in the Catholic press, rapid train transportation and cheaper
package fares opened an era of mass pilgrimage to Rome and paved the
way for a new popular papal style.
Exact statistical properties of the Burgers equation
Authors: FRACHEBOURG L. , MARTIN Ph. A.
Published: July 2002

The one-dimensional Burgers equation in the inviscid limit with white noise initial
condition is revisited. The one- and two-point distributions of the Burgers field as
well as the related distributions of shocks are obtained in closed analytical forms.
In particular, the large distance behaviour of spatial correlations of the field is
determined. Since higher-order distributions factorize in terms of the one- and two-
point functions, our analysis provides an explicit and complete statistical description
of this problem.
The dynamics of two-layer gravity-driven flows in permeable rock
Authors: WOODS ANDREW W. , MASON ROBERT
Published: July 2002

We examine the motion of a two-layer gravity current, composed of two fluids of
different viscosity and density, as it propagates through a model porous layer. We
focus on two specific situations: first, the case in which each layer of fluid has finite
volume, and secondly, the case in which each layer is supplied by a steady maintained
flux. In both cases, we find similarity solutions which describe the evolution of the
flow. These solutions illustrate how the morphology of the interface between the
two layers of fluid depends on the viscosity, density and volume ratios of the two
layers. We show that in the special case that the viscosity ratio of the upper to
lower layers, V, satisfies V = (1 + F)/(1 + RF)
where F and R are respectively the
ratios of the volume and buoyancy of the lower layer to those of the upper layer,
then the ratio of layer depths is the same at all points. Furthermore, we show
that for V > (<)(1 + F)/(1 + RF), the lower (upper) layer advances ahead of the
upper (lower) layer. We also present some new laboratory experiments on two-layer
gravity currents, using a Hele-Shaw cell, and show that these are in accord with the
model predictions. One interesting prediction of the model, which is confirmed by
the experiments, is that for a finite volume release, if the viscosity ratio is sufficiently
large, then the less-viscous layer separates from the source. We extend the model to
describe the propagation of a layer of fluid which is continuously stratified in either
density or viscosity, and we briefly discuss application of the results for modelling
various two-layer gravity-driven flows in permeable rock.
On constructing realizable, conservative mixed scalar equations using the eddy-damped quasi-normal Markovian theory
Authors: ULITSKY MARK , COLLINS LANCE R.
Published: July 2002

The eddy-damped quasi-normal Markovian (EDQNM) turbulence theory has been
applied to the covariance spectrum of two passive isotropic scalars with different
diffusivities in stationary isotropic turbulence. A rigorous application of EDQNM,
which introduces no new modelling assumptions or constants, is shown to yield a
covariance spectrum that violates the Cauchy–Schwartz inequality over some of the
wavenumbers. One approach to this problem is to derive a model based on a stochastic
differential equation, as its presence guarantees realizability. For an isotropic scalar,
it is possible to construct a Langevin equation for the Fourier transform of the scalar
concentrations that is consistent with each EDQNM scalar autocorrelation spectrum.
The Langevin equations can then be used to construct a model for the covariance
spectrum that is realizable. However, the resulting covariance transfer term does not
properly conserve the scalar covariance, and so the model is still not satisfactory. The
problem can be traced to the Markovianization step, which leads to the presence of
the scalar diffusivities in the transfer functions in an unphysical fashion. A simple fix
is described which reconciles the two approaches and gives conservative, realizable
results for all time.

Next, we apply the EDQNM theory to a more general system involving the mixing
of anisotropic scalars. Anisotropy in this case results from a uniform mean gradient
of the two scalar concentrations in one direction. As with the isotropic scalars, direct
application of the EDQNM closure results in a covariance spectrum that violates the
Cauchy–Schwartz inequality; however, in this case it is not as simple to construct a
Langevin model that reproduces all of the spectral interactions that result from the
EDQNM procedure. Nevertheless, we show that the same modification of the inverse
time scale as is done for the isotropic scalar results in an anisotropic scalar covariance
spectrum that is realizable for all times.
Nonlinear stability of a fluid-loaded elastic plate with mean flow
Authors: PEAKE N.
Published: July 2002

It has been known for some time that the unsteady interaction between a simple
elastic plate and a mean flow has a number of interesting features, which include,
but are not limited to, the existence of negative-energy waves (NEWs) which are
destabilized by the introduction of dashpot dissipation, and convective instabilities
associated with the flow–surface interaction. In this paper we consider the nonlinear
evolution of these two types of waves in uniform mean flow. It is shown that the NEW
can become saturated at weakly nonlinear amplitude. For general parameter values
this saturation can be achieved for wavenumber k corresponding to low-frequency
oscillations, but in the realistic case in which the coefficient of the nonlinear tension
term (in our normalization proportional to the square of the solid–fluid density
ratio) is large, saturation is achieved for all k in the NEW range. In both cases the
nonlinearities act so as increase the restorative stiffness in the plate, the oscillation
frequency of the dashpots driving the NEW instability decreases, and the system
approaches a state of static deflection (in agreement with the results of the numerical
simulations of Lucey et al. 1997). With regard to the marginal convective instability,
we show that the wave-train evolution is described by the defocusing form of the
nonlinear Schrödinger (NLS) equation, suggesting (at least for wave trains with
compact support) that in the long-time limit the marginal convective instability
decays to zero. In contrast, expansion about a range of other points on the neutral
curve yields the focusing form of the NLS equation, allowing the existence of isolated
soliton solutions, whose amplitude is shown to be potentially significant for realistic
parameter values. Moreover, when slow spanwise modulation is included, it turns out
that even the marginal convective instability can exhibit solitary-wave behaviour for
modulation directions lying outside broad wedges about the flow direction.
An integral model for gas entrainment into full cone sprays
Authors: COSSALI G. E.
Published: July 2002

The paper proposes a one-dimensional model for predicting gas entrainment into
a non-evaporating full cone steady spray injected into a stagnant gas at uniform
pressure. The main outcome is a law relating the entrained mass flow rate to injected
mass flow rate, gas properties, mean droplet diameter and axial distance from the
nozzle. A comparison with available experimental data is presented. The model
allows the apparent inconsistency of the experimental results obtained under different
conditions to be eliminated by identifying two new non-dimensional parameters.
Global dynamics of symmetric and asymmetric wakes
Authors: HAMMOND D. A. , REDEKOPP L. G.
Published: July 2002

The two-dimensional wake–shear layer forming behind a
rectangular-based forebody with independent ambient streams on either
side of the forebody is examined by direct numerical simulation.
Theoretical aspects of global modes and frequency selection criteria
based on local and global stability arguments are tested by computing
local stability properties using local, time-averaged velocity profiles
obtained from the numerical simulations and making the parallel-flow
approximation. The theoretical results based on the assumption of a
slightly non-parallel, spatially developing flow are shown to provide a
firm basis for the frequency selection of vortex shedding and for
defining the conditions for its onset. Distributed suction or blowing
applied at the base of the forebody is used as a means of wake flow
modification. The critical suction velocity to suppress vortex shedding
is calculated. It is shown that local directional control (i.e.
vectoring) of the near-wake flow is possible, but only when all global
modes are suppressed.
Symmetry breaking and overturning oscillations in
thermohaline-driven flows
Authors: DIJKSTRA HENK A. , MOLEMAKER M. JEROEN
Published: July 2002

The bifurcation structure of thermohaline-driven flows is
studied within one of the simplest zonally averaged models which
captures thermohaline transport: a Boussinesq model of
surface-forced thermohaline flow in a two-dimensional rectangular
basin. Under mixed boundary conditions, i.e. prescribed surface
temperature and fresh-water flux, it is shown that symmetry breaking
originates from a codimension-two singularity which arises through
the intersection of the paths of two symmetry-breaking pitchfork
bifurcations. The physical mechanism of symmetry breaking of both the
thermally and salinity dominated symmetric solution is described in
detail from the perturbation structures near bifurcation. Limit
cycles with an oscillation period in the order of the overturning
time scale arise through Hopf bifurcations on the branches of
asymmetric steady solutions. The physical mechanism of oscillation is
described in terms of the most unstable mode just at the Hopf
bifurcation. The occurrence of these oscillations is quite sensitive
to the shape of the prescribed fresh-water flux. Symmetry breaking
still occurs when, instead of a fixed temperature, a Newtonian
cooling condition is prescribed at the surface. There is only
quantitative sensitivity, i.e. the positions of the bifurcation
points shift with the surface heat transfer coefficient. There are no
qualitative changes in the bifurcation diagram except in the limit
where both the surface heat flux and fresh-water flux are prescribed.
The bifurcation structure at large aspect ratio is shown to converge
to that obtained by asymptotic theory. The complete structure of
symmetric and asymmetric multiple equilibria is shown to originate
from a codimension-three bifurcation, which arises through the
intersection of a cusp and the codimension-two singularity
responsible for symmetry breaking.
Influence of camber on sound generation by

airfoils interacting with high-frequency gusts
Authors: MYERS MATTHEW R. , KERSCHEN E. J.
Published: July 2002

A theoretical model is developed for the sound generated when a

convected disturbance encounters a cambered airfoil at non-zero angle of

attack. The model is

a generalization of a previous theory for a flat-plate airfoil, and

is based on a linearization of the Euler equations about the steady,

subsonic flow past the airfoil.

High-frequency gusts, whose wavelengths are short compared to the airfoil
chord, are

considered. The airfoil camber and incidence angle are restricted so that
the mean

flow past the airfoil is a small perturbation to a uniform flow. The

singular perturbation analysis retains the asymptotic regions present in

the case of a flat-plate airfoil:

local regions, which scale on the gust wavelength, at the airfoil leading

and trailing

edges; a ‘transition’ region behind the airfoil which is similar

to the transition zone

between illuminated and shadow regions in optical problems; and an outer
region, far

away from the airfoil edges and wake, in which the solution has a

geometric-acoustics

form. For the cambered airfoil, an additional asymptotic region in the
form of an

acoustic boundary layer adjacent to the airfoil surface is required

in order to account

for surface curvature effects. Parametric calculations are presented which
illustrate

that, like incidence angle, moderate amounts of airfoil camber can

significantly affect

the sound field produced by airfoil–gust interactions. Most importantly,

the amount

of radiated sound power is found to correlate very well with a single aerodynamic

loading parameter, αeff, which is an

effective mean-flow incidence angle for the airfoil leading edge.
On linear and nonlinear instability of
the incompressible swept attachment-line boundary layer
Authors: THEOFILIS VASSILIOS
Published: July 2002

The stability of an incompressible swept attachment-line
boundary layer flow is studied
numerically, within the Görtler–Hämmerlin
framework, in both the linear and nonlinear two-dimensional
regimes in a self-consistent manner. The initial-boundary-value
problem resulting from substitution of small-amplitude excitation
into the incompressible Navier–Stokes equations
and linearization about the generalized Hiemenz
profile is solved. A comprehensive comparison of all linear
approaches utilized to
date is presented and it is demonstrated that the linear
initial-boundary-value problem
formulation delivers results in excellent agreement with
those obtained by solution of
either the temporal or the spatial linear stability theory
eigenvalue problem for both
zero suction and a layer in which blowing is applied. In
the latter boundary layer
recent experiments have documented the growth of instability
waves with frequencies
in a range encompassed by that of the unstable
Görtler–Hämmerlin linear modes
found in our simulations. In order to enable further
comparisons with experiment
and, thus, assess the validity of the
Görtler–Hämmerlin theoretical model, we make
available the spatial structure of the eigenfunctions at
maximum growth conditions.

The condition on smallness of the imposed excitation is
subsequently relaxed and
the resulting nonlinear initial-boundary-value problem is
solved. Extensive numerical
experimentation has been performed which has verified
theoretical predictions on
the way in which the solution is expected to bifurcate from
the linear neutral loop.
However, it is demonstrated that the two-dimensional
model equations considered do
not deliver subcritical instability of this flow; this
strengthens the conjecture that three-dimensionality is,
at least partly, responsible for the observed discrepancy
between the linear theory critical Reynolds number and the
subcritical turbulence observed either
experimentally or in three-dimensional numerical simulations.
Further, the present
nonlinear computations demonstrate that the unstable
flow has its line of maximum
amplification in the neighbourhood of the experimentally
observed instability waves,
in a manner analogous to the Blasius boundary layer. In
line with previous eigenvalue
problem and direct simulation work, suction is observed to
be a powerful stabilization
mechanism for naturally occurring instabilities of small amplitude.